diff --git a/deps/CMakeLists.txt b/deps/CMakeLists.txt
index 1e59396c702dfa9c67eee09a3aed5cc6b421abf4..a4db6fd5fbc3e867cd30d2a1c871e48a7bfbd5eb 100644
--- a/deps/CMakeLists.txt
+++ b/deps/CMakeLists.txt
@@ -9,6 +9,7 @@ ADD_SUBDIRECTORY(lz4)
 ADD_SUBDIRECTORY(cJson)
 ADD_SUBDIRECTORY(wepoll)
 ADD_SUBDIRECTORY(MsvcLibX)
+ADD_SUBDIRECTORY(rmonotonic)
 
 IF (TD_LINUX AND TD_MQTT)
   ADD_SUBDIRECTORY(MQTT-C)
diff --git a/deps/MsvcLibX/include/msvcTime.h b/deps/MsvcLibX/include/msvcTime.h
index 1897da58570cf503b05502d0a15c899f1f126015..6f8b5dac8f88e4c3dd40445f1c5512ba2e6e796f 100644
--- a/deps/MsvcLibX/include/msvcTime.h
+++ b/deps/MsvcLibX/include/msvcTime.h
@@ -38,6 +38,7 @@
 typedef int clockid_t;
 /* Supported values for clockid_t */
 #define CLOCK_REALTIME 0
+#define CLOCK_MONOTONIC 1
 
 int clock_gettime(clockid_t clock_id, struct timespec *tp);
 
diff --git a/deps/MsvcLibX/src/clock_gettime.c b/deps/MsvcLibX/src/clock_gettime.c
index fee7532e2e552ec08b615e61e3f4d79276ea6cfc..cbddf7107ae3733186c014c26a769f3f9d386d0e 100644
--- a/deps/MsvcLibX/src/clock_gettime.c
+++ b/deps/MsvcLibX/src/clock_gettime.c
@@ -34,15 +34,56 @@
 #include "msvcTime.h"
 #include "sys/msvcStat.h" /* For MsvcLibX's Filetime2Timespec */
 
-int clock_gettime(clockid_t clock_id, struct timespec *pTS) {
-  FILETIME ft;
-  if (clock_id != CLOCK_REALTIME) {
-    errno = EINVAL;
-    return -1;
+#define MS_PER_SEC      1000ULL     // MS = milliseconds
+#define US_PER_MS       1000ULL     // US = microseconds
+#define HNS_PER_US      10ULL       // HNS = hundred-nanoseconds (e.g., 1 hns = 100 ns)
+#define NS_PER_US       1000ULL
+
+#define HNS_PER_SEC     (MS_PER_SEC * US_PER_MS * HNS_PER_US)
+#define NS_PER_HNS      (100ULL)    // NS = nanoseconds
+#define NS_PER_SEC      (MS_PER_SEC * US_PER_MS * NS_PER_US)
+
+int clock_gettime_monotonic(struct timespec *tv) {
+  static LARGE_INTEGER ticksPerSec;
+  LARGE_INTEGER ticks;
+  double seconds;
+
+  if (!ticksPerSec.QuadPart) {
+    QueryPerformanceFrequency(&ticksPerSec);
+    if (!ticksPerSec.QuadPart) {
+      errno = ENOTSUP;
+      return -1;
+    }
   }
+
+  QueryPerformanceCounter(&ticks);
+
+  seconds = (double) ticks.QuadPart / (double) ticksPerSec.QuadPart;
+  tv->tv_sec = (time_t)seconds;
+  tv->tv_nsec = (long)((ULONGLONG)(seconds * NS_PER_SEC) % NS_PER_SEC);
+
+  return 0;
+}
+
+int clock_gettime_realtime(struct timespec *pTS) {
+  FILETIME ft;
+
   GetSystemTimeAsFileTime(&ft);
   Filetime2Timespec(&ft, pTS);
+
   return 0;
 }
 
+int clock_gettime(clockid_t clock_id, struct timespec *pTS) {
+  if (clock_id == CLOCK_MONOTONIC) {
+    return clock_gettime_monotonic(pTS);
+  } else if (clock_id == CLOCK_REALTIME) {
+    return clock_gettime_realtime(pTS);
+  }
+
+  errno = ENOTSUP;
+
+  return -1;
+}
+
 #endif /* defined(_WIN32) */
diff --git a/deps/rmonotonic/CMakeLists.txt b/deps/rmonotonic/CMakeLists.txt
new file mode 100644
index 0000000000000000000000000000000000000000..b870b7d6d7a3817c38bfd4c488f75890fd115b7f
--- /dev/null
+++ b/deps/rmonotonic/CMakeLists.txt
@@ -0,0 +1,11 @@
+AUX_SOURCE_DIRECTORY(${CMAKE_CURRENT_SOURCE_DIR}/src SOURCE_LIST)
+
+add_definitions(-DUSE_PROCESSOR_CLOCK)
+
+INCLUDE_DIRECTORIES(${CMAKE_CURRENT_SOURCE_DIR}/../MsvcLibX/include)
+
+ADD_LIBRARY(rmonotonic ${SOURCE_LIST})
+TARGET_INCLUDE_DIRECTORIES(rmonotonic PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/inc)
+IF (TD_WINDOWS)
+  TARGET_LINK_LIBRARIES(rmonotonic MsvcLibXw)
+ENDIF ()
diff --git a/deps/rmonotonic/inc/monotonic.h b/deps/rmonotonic/inc/monotonic.h
new file mode 100644
index 0000000000000000000000000000000000000000..0850548d36629b0b1bfba04e818937e275cac5bf
--- /dev/null
+++ b/deps/rmonotonic/inc/monotonic.h
@@ -0,0 +1,56 @@
+#ifndef __MONOTONIC_H
+#define __MONOTONIC_H
+/* The monotonic clock is an always increasing clock source.  It is unrelated to
+ * the actual time of day and should only be used for relative timings.  The
+ * monotonic clock is also not guaranteed to be chronologically precise; there
+ * may be slight skew/shift from a precise clock.
+ *
+ * Depending on system architecture, the monotonic time may be able to be
+ * retrieved much faster than a normal clock source by using an instruction
+ * counter on the CPU.  On x86 architectures (for example), the RDTSC
+ * instruction is a very fast clock source for this purpose.
+ */
+
+//#include "fmacros.h"
+#include <stdint.h>
+//#include <unistd.h>
+
+#if defined(_WIN32) || defined(_WIN64)
+  #define inline
+#endif
+
+/* A counter in micro-seconds.  The 'monotime' type is provided for variables
+ * holding a monotonic time.  This will help distinguish & document that the
+ * variable is associated with the monotonic clock and should not be confused
+ * with other types of time.*/
+typedef uint64_t monotime;
+
+/* Retrieve counter of micro-seconds relative to an arbitrary point in time.  */
+extern monotime (*getMonotonicUs)(void);
+
+
+/* Call once at startup to initialize the monotonic clock.  Though this only
+ * needs to be called once, it may be called additional times without impact.
+ * Returns a printable string indicating the type of clock initialized.
+ * (The returned string is static and doesn't need to be freed.)  */
+const char * monotonicInit();
+
+
+/* Functions to measure elapsed time.  Example:
+ *     monotime myTimer;
+ *     elapsedStart(&myTimer);
+ *     while (elapsedMs(myTimer) < 10) {} // loops for 10ms
+ */
+static inline void elapsedStart(monotime *start_time) {
+    *start_time = getMonotonicUs();
+}
+
+static inline uint64_t elapsedUs(monotime start_time) {
+    return getMonotonicUs() - start_time;
+}
+
+static inline uint64_t elapsedMs(monotime start_time) {
+    return elapsedUs(start_time) / 1000;
+}
+
+#endif
diff --git a/deps/rmonotonic/src/monotonic.c b/deps/rmonotonic/src/monotonic.c
new file mode 100644
index 0000000000000000000000000000000000000000..622ac1b075a66ec49338cda3cc4afbc8355636dd
--- /dev/null
+++ b/deps/rmonotonic/src/monotonic.c
@@ -0,0 +1,173 @@
+#include "monotonic.h"
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <time.h>
+
+#undef NDEBUG
+#include <assert.h>
+
+#if defined(_WIN32) || defined(_WIN64)
+#include "msvcTime.h"
+#include "msvcStdio.h"
+#endif
+
+/* The function pointer for clock retrieval.  */
+monotime (*getMonotonicUs)(void) = NULL;
+
+static char monotonic_info_string[32];
+
+
+/* Using the processor clock (aka TSC on x86) can provide improved performance
+ * throughout Redis wherever the monotonic clock is used.  The processor clock
+ * is significantly faster than calling 'clock_getting' (POSIX).  While this is
+ * generally safe on modern systems, this link provides additional information
+ * about use of the x86 TSC: http://oliveryang.net/2015/09/pitfalls-of-TSC-usage
+ *
+ * To use the processor clock, either uncomment this line, or build with
+ *   CFLAGS="-DUSE_PROCESSOR_CLOCK"
+#define USE_PROCESSOR_CLOCK
+ */
+
+
+#if defined(USE_PROCESSOR_CLOCK) && defined(__x86_64__) && defined(__linux__)
+#include <regex.h>
+#include <x86intrin.h>
+
+static long mono_ticksPerMicrosecond = 0;
+
+static monotime getMonotonicUs_x86() {
+    return __rdtsc() / mono_ticksPerMicrosecond;
+}
+
+static void monotonicInit_x86linux() {
+    const int bufflen = 256;
+    char buf[bufflen];
+    regex_t cpuGhzRegex, constTscRegex;
+    const size_t nmatch = 2;
+    regmatch_t pmatch[nmatch];
+    int constantTsc = 0;
+    int rc;
+
+    /* Determine the number of TSC ticks in a micro-second.  This is
+     * a constant value matching the standard speed of the processor.
+     * On modern processors, this speed remains constant even though
+     * the actual clock speed varies dynamically for each core.  */
+    rc = regcomp(&cpuGhzRegex, "^model name\\s+:.*@ ([0-9.]+)GHz", REG_EXTENDED);
+    assert(rc == 0);
+
+    /* Also check that the constant_tsc flag is present.  (It should be
+     * unless this is a really old CPU.  */
+    rc = regcomp(&constTscRegex, "^flags\\s+:.* constant_tsc", REG_EXTENDED);
+    assert(rc == 0);
+
+    FILE *cpuinfo = fopen("/proc/cpuinfo", "r");
+    if (cpuinfo != NULL) {
+        while (fgets(buf, bufflen, cpuinfo) != NULL) {
+            if (regexec(&cpuGhzRegex, buf, nmatch, pmatch, 0) == 0) {
+                buf[pmatch[1].rm_eo] = '\0';
+                double ghz = atof(&buf[pmatch[1].rm_so]);
+                mono_ticksPerMicrosecond = (long)(ghz * 1000);
+                break;
+            }
+        }
+        while (fgets(buf, bufflen, cpuinfo) != NULL) {
+            if (regexec(&constTscRegex, buf, nmatch, pmatch, 0) == 0) {
+                constantTsc = 1;
+                break;
+            }
+        }
+
+        fclose(cpuinfo);
+    }
+    regfree(&cpuGhzRegex);
+    regfree(&constTscRegex);
+
+    if (mono_ticksPerMicrosecond == 0) {
+        fprintf(stderr, "monotonic: x86 linux, unable to determine clock rate");
+        return;
+    }
+    if (!constantTsc) {
+        fprintf(stderr, "monotonic: x86 linux, 'constant_tsc' flag not present");
+        return;
+    }
+
+    snprintf(monotonic_info_string, sizeof(monotonic_info_string),
+            "X86 TSC @ %ld ticks/us", mono_ticksPerMicrosecond);
+    getMonotonicUs = getMonotonicUs_x86;
+}
+#endif
+
+
+#if defined(USE_PROCESSOR_CLOCK) && defined(__aarch64__)
+static long mono_ticksPerMicrosecond = 0;
+
+/* Read the clock value.  */
+static inline uint64_t __cntvct() {
+    uint64_t virtual_timer_value;
+    __asm__ volatile("mrs %0, cntvct_el0" : "=r"(virtual_timer_value));
+    return virtual_timer_value;
+}
+
+/* Read the Count-timer Frequency.  */
+static inline uint32_t cntfrq_hz() {
+    uint64_t virtual_freq_value;
+    __asm__ volatile("mrs %0, cntfrq_el0" : "=r"(virtual_freq_value));
+    return (uint32_t)virtual_freq_value;    /* top 32 bits are reserved */
+}
+
+static monotime getMonotonicUs_aarch64() {
+    return __cntvct() / mono_ticksPerMicrosecond;
+}
+
+static void monotonicInit_aarch64() {
+    mono_ticksPerMicrosecond = (long)cntfrq_hz() / 1000L / 1000L;
+    if (mono_ticksPerMicrosecond == 0) {
+        fprintf(stderr, "monotonic: aarch64, unable to determine clock rate");
+        return;
+    }
+
+    snprintf(monotonic_info_string, sizeof(monotonic_info_string),
+            "ARM CNTVCT @ %ld ticks/us", mono_ticksPerMicrosecond);
+    getMonotonicUs = getMonotonicUs_aarch64;
+}
+#endif
+
+static monotime getMonotonicUs_posix(void) {
+    /* clock_gettime() is specified in POSIX.1b (1993).  Even so, some systems
+     * did not support this until much later.  CLOCK_MONOTONIC is technically
+     * optional and may not be supported - but it appears to be universal.
+     * If this is not supported, provide a system-specific alternate version.  */
+    struct timespec ts;
+    clock_gettime(CLOCK_MONOTONIC, &ts);
+    return ((uint64_t)ts.tv_sec) * 1000000 + ts.tv_nsec / 1000;
+}
+
+static void monotonicInit_posix() {
+    /* Ensure that CLOCK_MONOTONIC is supported.  This should be supported
+     * on any reasonably current OS.  If the assertion below fails, provide
+     * an appropriate alternate implementation.  */
+    struct timespec ts;
+    int rc = clock_gettime(CLOCK_MONOTONIC, &ts);
+    assert(rc == 0);
+
+    snprintf(monotonic_info_string, sizeof(monotonic_info_string),
+            "POSIX clock_gettime");
+    getMonotonicUs = getMonotonicUs_posix;
+}
+
+
+
+const char * monotonicInit() {
+    #if defined(USE_PROCESSOR_CLOCK) && defined(__x86_64__) && defined(__linux__)
+    if (getMonotonicUs == NULL) monotonicInit_x86linux();
+    #endif
+
+    #if defined(USE_PROCESSOR_CLOCK) && defined(__aarch64__)
+    if (getMonotonicUs == NULL) monotonicInit_aarch64();
+    #endif
+
+    if (getMonotonicUs == NULL) monotonicInit_posix();
+
+    return monotonic_info_string;
+}
diff --git a/packaging/cfg/taos.cfg b/packaging/cfg/taos.cfg
index 73004fe7b722d2fd2c15930f69a38d78aca4220d..5ac0e39dcc134260945d5328ac8035559574f277 100644
--- a/packaging/cfg/taos.cfg
+++ b/packaging/cfg/taos.cfg
@@ -270,3 +270,9 @@
 
 # in retrieve blocking model, only in 50% query threads will be used in query processing in dnode
 # retrieveBlockingModel    0
+
+# the maximum allowed query buffer size in MB during query processing for each data node
+# -1 no limit (default)
+# 0  no query allowed, queries are disabled
+# queryBufferSize         -1
+
diff --git a/packaging/deb/makedeb.sh b/packaging/deb/makedeb.sh
index 431093be950e2c2bb199ed294b57641290fe6221..850c636940a34e5a2b58c227e1fd105fb57fa285 100755
--- a/packaging/deb/makedeb.sh
+++ b/packaging/deb/makedeb.sh
@@ -47,6 +47,9 @@ cp ${compile_dir}/../packaging/cfg/taos.cfg         ${pkg_dir}${install_home_pat
 cp ${compile_dir}/../packaging/deb/taosd            ${pkg_dir}${install_home_path}/init.d
 cp ${compile_dir}/../packaging/tools/post.sh        ${pkg_dir}${install_home_path}/script
 cp ${compile_dir}/../packaging/tools/preun.sh       ${pkg_dir}${install_home_path}/script
+cp ${compile_dir}/../packaging/tools/startPre.sh    ${pkg_dir}${install_home_path}/bin
+cp ${compile_dir}/../packaging/tools/set_core.sh    ${pkg_dir}${install_home_path}/bin
+cp ${compile_dir}/../packaging/tools/taosd-dump-cfg.gdb    ${pkg_dir}${install_home_path}/bin
 cp ${compile_dir}/build/bin/taosdemo                ${pkg_dir}${install_home_path}/bin
 cp ${compile_dir}/build/bin/taosdemox               ${pkg_dir}${install_home_path}/bin
 cp ${compile_dir}/build/bin/taosdump                ${pkg_dir}${install_home_path}/bin
diff --git a/packaging/rpm/tdengine.spec b/packaging/rpm/tdengine.spec
index 6f012aa80eac67ba42e7ca561c95ef6d905c2100..d20a6c91cdd78a8c54b89b14d7b77807ebef4877 100644
--- a/packaging/rpm/tdengine.spec
+++ b/packaging/rpm/tdengine.spec
@@ -55,6 +55,9 @@ cp %{_compiledir}/../packaging/cfg/taos.cfg         %{buildroot}%{homepath}/cfg
 cp %{_compiledir}/../packaging/rpm/taosd            %{buildroot}%{homepath}/init.d
 cp %{_compiledir}/../packaging/tools/post.sh        %{buildroot}%{homepath}/script
 cp %{_compiledir}/../packaging/tools/preun.sh       %{buildroot}%{homepath}/script
+cp %{_compiledir}/../packaging/tools/startPre.sh    %{buildroot}%{homepath}/bin
+cp %{_compiledir}/../packaging/tools/set_core.sh    %{buildroot}%{homepath}/bin
+cp %{_compiledir}/../packaging/tools/taosd-dump-cfg.gdb    %{buildroot}%{homepath}/bin
 cp %{_compiledir}/build/bin/taos                    %{buildroot}%{homepath}/bin
 cp %{_compiledir}/build/bin/taosd                   %{buildroot}%{homepath}/bin
 cp %{_compiledir}/build/bin/taosdemo                %{buildroot}%{homepath}/bin
diff --git a/packaging/tools/install.sh b/packaging/tools/install.sh
index d98ed2185f014356fcf6e954bd717be98a960d16..9cec9963af6f8abdcaedeeb4e7d40f9244508be2 100755
--- a/packaging/tools/install.sh
+++ b/packaging/tools/install.sh
@@ -168,6 +168,7 @@ function install_main_path() {
     if [ "$verMode" == "cluster" ]; then
         ${csudo} mkdir -p ${nginx_dir}
     fi
+    ${csudo} cp ${script_dir}/email ${install_main_dir}/ ||: 
 }
 
 function install_bin() {
@@ -604,9 +605,7 @@ function install_service_on_systemd() {
     ${csudo} bash -c "echo '[Service]'                          >> ${taosd_service_config}"
     ${csudo} bash -c "echo 'Type=simple'                        >> ${taosd_service_config}"
     ${csudo} bash -c "echo 'ExecStart=/usr/bin/taosd'           >> ${taosd_service_config}"
-    #${csudo} bash -c "echo 'ExecStartPre=/usr/local/taos/bin/setDelay.sh'     >> ${taosd_service_config}"
-    #${csudo} bash -c "echo 'ExecStartPost=/usr/local/taos/bin/resetDelay.sh'  >> ${taosd_service_config}"
-    #${csudo} bash -c "echo 'ExecStopPost=/usr/local/taos/bin/resetDelay.sh'   >> ${taosd_service_config}"
+    ${csudo} bash -c "echo 'ExecStartPre=/usr/local/taos/bin/startPre.sh'         >> ${taosd_service_config}"
     ${csudo} bash -c "echo 'LimitNOFILE=infinity'               >> ${taosd_service_config}"
     ${csudo} bash -c "echo 'LimitNPROC=infinity'                >> ${taosd_service_config}"
     ${csudo} bash -c "echo 'LimitCORE=infinity'                 >> ${taosd_service_config}"
diff --git a/packaging/tools/install_power.sh b/packaging/tools/install_power.sh
index b14d5d400b9332c52f1559dcfef72a287d9fc385..89b5ce5b4f1f9edc91b7abbf459303cd8f632edf 100755
--- a/packaging/tools/install_power.sh
+++ b/packaging/tools/install_power.sh
@@ -578,6 +578,7 @@ function install_service_on_systemd() {
     ${csudo} bash -c "echo '[Service]'                           >> ${powerd_service_config}"
     ${csudo} bash -c "echo 'Type=simple'                         >> ${powerd_service_config}"
     ${csudo} bash -c "echo 'ExecStart=/usr/bin/powerd'           >> ${powerd_service_config}"
+    ${csudo} bash -c "echo 'ExecStartPre=/usr/local/power/bin/startPre.sh'           >> ${powerd_service_config}"
     ${csudo} bash -c "echo 'LimitNOFILE=infinity'                >> ${powerd_service_config}"
     ${csudo} bash -c "echo 'LimitNPROC=infinity'                 >> ${powerd_service_config}"
     ${csudo} bash -c "echo 'LimitCORE=infinity'                  >> ${powerd_service_config}"
diff --git a/packaging/tools/make_install.sh b/packaging/tools/make_install.sh
index 474b6f4619201d609cf9f41e50680d2d19e3ac3e..1fd0e943b155d0c96c26c3fdcec7061bd25197e4 100755
--- a/packaging/tools/make_install.sh
+++ b/packaging/tools/make_install.sh
@@ -149,10 +149,12 @@ function install_bin() {
     ${csudo} rm -f ${bin_link_dir}/rmtaos       || :
 
     ${csudo} cp -r ${binary_dir}/build/bin/* ${install_main_dir}/bin
+    ${csudo} cp -r ${script_dir}/taosd-dump-cfg.gdb   ${install_main_dir}/bin
 
     if [ "$osType" != "Darwin" ]; then
-        ${csudo} cp -r ${script_dir}/remove.sh   ${install_main_dir}/bin
+        ${csudo} cp -r ${script_dir}/remove.sh     ${install_main_dir}/bin
         ${csudo} cp -r ${script_dir}/set_core.sh   ${install_main_dir}/bin
+        ${csudo} cp -r ${script_dir}/startPre.sh   ${install_main_dir}/bin
     else
         ${csudo} cp -r ${script_dir}/remove_client.sh   ${install_main_dir}/bin
     fi
@@ -330,6 +332,7 @@ function install_service_on_systemd() {
     ${csudo} bash -c "echo '[Service]'                          >> ${taosd_service_config}"
     ${csudo} bash -c "echo 'Type=simple'                        >> ${taosd_service_config}"
     ${csudo} bash -c "echo 'ExecStart=/usr/bin/taosd'           >> ${taosd_service_config}"
+    ${csudo} bash -c "echo 'ExecStartPre=/usr/local/taos/bin/startPre.sh'           >> ${taosd_service_config}"
     ${csudo} bash -c "echo 'LimitNOFILE=infinity'               >> ${taosd_service_config}"
     ${csudo} bash -c "echo 'LimitNPROC=infinity'                >> ${taosd_service_config}"
     ${csudo} bash -c "echo 'LimitCORE=infinity'                 >> ${taosd_service_config}"
diff --git a/packaging/tools/makeclient.sh b/packaging/tools/makeclient.sh
index 00dfcb75590a50d23180e5eb2b6ad38f28924bba..52a4e059065ba666e9624800a24f267f74e454f9 100755
--- a/packaging/tools/makeclient.sh
+++ b/packaging/tools/makeclient.sh
@@ -45,7 +45,8 @@ if [ "$osType" != "Darwin" ]; then
     strip ${build_dir}/bin/taos
     bin_files="${build_dir}/bin/taos ${script_dir}/remove_client.sh"
   else  
-    bin_files="${build_dir}/bin/taos ${build_dir}/bin/taosdump ${build_dir}/bin/taosdemo ${build_dir}/bin/taosdemox ${script_dir}/remove_client.sh ${script_dir}/set_core.sh ${script_dir}/get_client.sh"
+    bin_files="${build_dir}/bin/taos ${build_dir}/bin/taosdump ${build_dir}/bin/taosdemo ${build_dir}/bin/taosdemox\
+               ${script_dir}/remove_client.sh ${script_dir}/set_core.sh ${script_dir}/get_client.sh ${script_dir}/taosd-dump-cfg.gdb"
   fi
   lib_files="${build_dir}/lib/libtaos.so.${version}"
 else
diff --git a/packaging/tools/makeclient_power.sh b/packaging/tools/makeclient_power.sh
index 509df31297d5b442a05516b37a1b82572ae4f610..15f8994e945aac89fc30b1fe7eaaf3c72ea8c105 100755
--- a/packaging/tools/makeclient_power.sh
+++ b/packaging/tools/makeclient_power.sh
@@ -81,6 +81,7 @@ if [ "$osType" != "Darwin" ]; then
     cp ${build_dir}/bin/taosdump      ${install_dir}/bin/powerdump  
     cp ${script_dir}/set_core.sh      ${install_dir}/bin
     cp ${script_dir}/get_client.sh    ${install_dir}/bin
+    cp ${script_dir}/taosd-dump-cfg.gdb    ${install_dir}/bin
   fi
 else
   cp ${bin_files} ${install_dir}/bin
diff --git a/packaging/tools/makepkg.sh b/packaging/tools/makepkg.sh
index 0b4659a9112f933a5ba9b91f52f3df203d18a2e7..267338ed06d528be84d13f4a871865f76b940344 100755
--- a/packaging/tools/makepkg.sh
+++ b/packaging/tools/makepkg.sh
@@ -36,7 +36,8 @@ if [ "$pagMode" == "lite" ]; then
   strip ${build_dir}/bin/taos
   bin_files="${build_dir}/bin/taosd ${build_dir}/bin/taos ${script_dir}/remove.sh"
 else 
-  bin_files="${build_dir}/bin/taosd ${build_dir}/bin/taos ${build_dir}/bin/taosdump ${build_dir}/bin/taosdemo ${build_dir}/bin/taosdemox ${build_dir}/bin/tarbitrator ${script_dir}/remove.sh ${script_dir}/set_core.sh ${script_dir}/get_client.sh"
+  bin_files="${build_dir}/bin/taosd ${build_dir}/bin/taos ${build_dir}/bin/taosdump ${build_dir}/bin/taosdemo ${build_dir}/bin/taosdemox ${build_dir}/bin/tarbitrator\
+             ${script_dir}/remove.sh ${script_dir}/set_core.sh ${script_dir}/startPre.sh  ${script_dir}/taosd-dump-cfg.gdb"
 fi
 
 lib_files="${build_dir}/lib/libtaos.so.${version}"
diff --git a/packaging/tools/makepkg_power.sh b/packaging/tools/makepkg_power.sh
index ba57fe5e9687b32b73a0a3ff4d48807f04a0202d..7227a08b7ab5e6fdfbdb4801fac3d174fe481f1e 100755
--- a/packaging/tools/makepkg_power.sh
+++ b/packaging/tools/makepkg_power.sh
@@ -36,7 +36,8 @@ fi
 #  strip ${build_dir}/bin/taos
 #  bin_files="${build_dir}/bin/powerd ${build_dir}/bin/power ${script_dir}/remove_power.sh"
 #else 
-#  bin_files="${build_dir}/bin/powerd ${build_dir}/bin/power ${build_dir}/bin/powerdemo ${build_dir}/bin/tarbitrator ${script_dir}/remove_power.sh ${script_dir}/set_core.sh"
+#  bin_files="${build_dir}/bin/powerd ${build_dir}/bin/power ${build_dir}/bin/powerdemo ${build_dir}/bin/tarbitrator ${script_dir}/remove_power.sh\
+#              ${script_dir}/set_core.sh ${script_dir}/startPre.sh  ${script_dir}/taosd-dump-cfg.gdb"
 #fi
 
 lib_files="${build_dir}/lib/libtaos.so.${version}"
@@ -82,6 +83,8 @@ else
   cp ${build_dir}/bin/tarbitrator   ${install_dir}/bin
   cp ${script_dir}/set_core.sh      ${install_dir}/bin
   cp ${script_dir}/get_client.sh    ${install_dir}/bin
+  cp ${script_dir}/startPre.sh      ${install_dir}/bin
+  cp ${script_dir}/taosd-dump-cfg.gdb  ${install_dir}/bin
 fi
 chmod a+x ${install_dir}/bin/* || :
 
diff --git a/packaging/tools/post.sh b/packaging/tools/post.sh
index 6bfbf33fd1dd8011e0fbd77322b9f104a0ab8c30..c6ef73932d8dbaedbe82fdc69997ef092c9953e7 100755
--- a/packaging/tools/post.sh
+++ b/packaging/tools/post.sh
@@ -406,6 +406,7 @@ function install_service_on_systemd() {
     ${csudo} bash -c "echo '[Service]'                          >> ${taosd_service_config}"
     ${csudo} bash -c "echo 'Type=simple'                        >> ${taosd_service_config}"
     ${csudo} bash -c "echo 'ExecStart=/usr/bin/taosd'           >> ${taosd_service_config}"
+    ${csudo} bash -c "echo 'ExecStartPre=/usr/local/taos/bin/startPre.sh'           >> ${taosd_service_config}"
     ${csudo} bash -c "echo 'LimitNOFILE=infinity'               >> ${taosd_service_config}"
     ${csudo} bash -c "echo 'LimitNPROC=infinity'                >> ${taosd_service_config}"
     ${csudo} bash -c "echo 'LimitCORE=infinity'                 >> ${taosd_service_config}"
diff --git a/packaging/tools/startPre.sh b/packaging/tools/startPre.sh
new file mode 100644
index 0000000000000000000000000000000000000000..3c16a5a938bdf3d7dc36c0a79f46e9c8f32b222b
--- /dev/null
+++ b/packaging/tools/startPre.sh
@@ -0,0 +1,50 @@
+#!/bin/bash
+#
+# if enable core dump, set start count to 3, disable core dump, set start count to 20.
+# set -e
+# set -x
+
+taosd=/etc/systemd/system/taosd.service
+line=`grep StartLimitBurst ${taosd}`
+num=${line##*=}
+#echo "burst num: ${num}"
+
+startSeqFile=/usr/local/taos/.startSeq
+recordFile=/usr/local/taos/.startRecord
+
+startSeq=0
+
+if [[ ! -e ${startSeqFile} ]]; then
+  startSeq=0
+else
+  startSeq=$(cat ${startSeqFile})
+fi
+   
+nextSeq=`expr $startSeq + 1`
+echo "${nextSeq}" > ${startSeqFile}
+
+curTime=$(date "+%Y-%m-%d %H:%M:%S")
+echo "startSeq:${startSeq} startPre.sh exec ${curTime}, burstCnt:${num}" >> ${recordFile}
+
+
+coreFlag=`ulimit -c`
+echo "coreFlag: ${coreFlag}" >> ${recordFile}
+
+if [ ${coreFlag} = "0" ];then
+  #echo "core is 0"
+  if [ ${num} != "20" ];then
+    sed -i "s/^.*StartLimitBurst.*$/StartLimitBurst=20/" ${taosd}
+    systemctl daemon-reload
+    echo "modify burst count from ${num} to 20" >> ${recordFile}
+  fi
+fi
+
+if [ ${coreFlag} = "unlimited" ];then
+  #echo "core is unlimited"
+  if [ ${num} != "3" ];then
+    sed -i "s/^.*StartLimitBurst.*$/StartLimitBurst=3/" ${taosd}
+    systemctl daemon-reload
+    echo "modify burst count from ${num} to 3" >> ${recordFile}
+  fi
+fi
+
diff --git a/src/client/inc/tsclient.h b/src/client/inc/tsclient.h
index 68cd2747e9ee39ce21de87964cf26ad19d14af66..c9702ad1fc7e83e1d7473ee040bafc33e6277c87 100644
--- a/src/client/inc/tsclient.h
+++ b/src/client/inc/tsclient.h
@@ -297,6 +297,11 @@ typedef struct {
   struct SLocalMerger  *pLocalMerger;
 } SSqlRes;
 
+typedef struct {
+  char         key[512]; 
+  void         *pDnodeConn; 
+} SRpcObj;
+
 typedef struct STscObj {
   void *             signature;
   void *             pTimer;
@@ -312,8 +317,8 @@ typedef struct STscObj {
   int64_t            hbrid;
   struct SSqlObj *   sqlList;
   struct SSqlStream *streamList;
-  SRpcCorEpSet       *tscCorMgmtEpSet;
-  void*              pDnodeConn;
+  SRpcObj           *pRpcObj;
+  SRpcCorEpSet      *tscCorMgmtEpSet;
   pthread_mutex_t    mutex;
   int32_t            numOfObj; // number of sqlObj from this tscObj
 } STscObj;
@@ -390,8 +395,10 @@ typedef struct SSqlStream {
 
 void tscSetStreamDestTable(SSqlStream* pStream, const char* dstTable);
 
-int32_t tscInitRpc(const char *user, const char *secret, void** pDnodeConn);
-void    tscInitMsgsFp();
+
+int  tscAcquireRpc(const char *key, const char *user, const char *secret,void **pRpcObj);
+void tscReleaseRpc(void *param);
+void tscInitMsgsFp();
 
 int tsParseSql(SSqlObj *pSql, bool initial);
 
diff --git a/src/client/src/tscSQLParser.c b/src/client/src/tscSQLParser.c
index ec699408de943f228e2c0aa7057f265bc9fc446a..4811a3b35d3fc15be5af78cff8d420868637da9b 100644
--- a/src/client/src/tscSQLParser.c
+++ b/src/client/src/tscSQLParser.c
@@ -5427,6 +5427,7 @@ int32_t validateColumnName(char* name) {
 
   if (token.type == TK_STRING) {
     strdequote(token.z);
+    strntolower(token.z, token.z, token.n);
     token.n = (uint32_t)strtrim(token.z);
 
     int32_t k = tSQLGetToken(token.z, &token.type);
diff --git a/src/client/src/tscServer.c b/src/client/src/tscServer.c
index 6035a270c5494560744b12cfa77c7449ca2fcb06..bcffbde6583ffed4b896ba4f1882cafe1d547685 100644
--- a/src/client/src/tscServer.c
+++ b/src/client/src/tscServer.c
@@ -157,13 +157,16 @@ void tscProcessHeartBeatRsp(void *param, TAOS_RES *tres, int code) {
     SRpcEpSet     *epSet = &pRsp->epSet;
     if (epSet->numOfEps > 0) {
       tscEpSetHtons(epSet);
-      if (!tscEpSetIsEqual(&pSql->pTscObj->tscCorMgmtEpSet->epSet, epSet)) {
-        tscTrace("%p updating epset: numOfEps: %d, inUse: %d", pSql, epSet->numOfEps, epSet->inUse);
-        for (int8_t i = 0; i < epSet->numOfEps; i++) {
-          tscTrace("endpoint %d: fqdn=%s, port=%d", i, epSet->fqdn[i], epSet->port[i]);
-        }
-        tscUpdateMgmtEpSet(pSql, epSet);
-      }
+
+      //SRpcCorEpSet *pCorEpSet = pSql->pTscObj->tscCorMgmtEpSet;
+      //if (!tscEpSetIsEqual(&pCorEpSet->epSet, epSet)) {
+      //  tscTrace("%p updating epset: numOfEps: %d, inUse: %d", pSql, epSet->numOfEps, epSet->inUse);
+      //  for (int8_t i = 0; i < epSet->numOfEps; i++) {
+      //    tscTrace("endpoint %d: fqdn=%s, port=%d", i, epSet->fqdn[i], epSet->port[i]);
+      //  }
+      //}
+      //concurrency problem, update mgmt epset anyway 
+      tscUpdateMgmtEpSet(pSql, epSet);
     }
 
     pSql->pTscObj->connId = htonl(pRsp->connId);
@@ -270,7 +273,8 @@ int tscSendMsgToServer(SSqlObj *pSql) {
       .code    = 0
   };
 
-  rpcSendRequest(pObj->pDnodeConn, &pSql->epSet, &rpcMsg, &pSql->rpcRid);
+  
+  rpcSendRequest(pObj->pRpcObj->pDnodeConn, &pSql->epSet, &rpcMsg, &pSql->rpcRid);
   return TSDB_CODE_SUCCESS;
 }
 
@@ -292,8 +296,8 @@ void tscProcessMsgFromServer(SRpcMsg *rpcMsg, SRpcEpSet *pEpSet) {
   if (pObj->signature != pObj) {
     tscDebug("%p DB connection is closed, cmd:%d pObj:%p signature:%p", pSql, pCmd->command, pObj, pObj->signature);
 
-    taosRemoveRef(tscObjRef, pSql->self);
-    taosReleaseRef(tscObjRef, pSql->self);
+    taosRemoveRef(tscObjRef, handle);
+    taosReleaseRef(tscObjRef, handle);
     rpcFreeCont(rpcMsg->pCont);
     return;
   }
@@ -303,8 +307,8 @@ void tscProcessMsgFromServer(SRpcMsg *rpcMsg, SRpcEpSet *pEpSet) {
     tscDebug("%p sqlObj needs to be released or DB connection is closed, cmd:%d type:%d, pObj:%p signature:%p",
         pSql, pCmd->command, pQueryInfo->type, pObj, pObj->signature);
 
-    taosRemoveRef(tscObjRef, pSql->self);
-    taosReleaseRef(tscObjRef, pSql->self);
+    taosRemoveRef(tscObjRef, handle);
+    taosReleaseRef(tscObjRef, handle);
     rpcFreeCont(rpcMsg->pCont);
     return;
   }
@@ -350,7 +354,7 @@ void tscProcessMsgFromServer(SRpcMsg *rpcMsg, SRpcEpSet *pEpSet) {
 
       // if there is an error occurring, proceed to the following error handling procedure.
       if (rpcMsg->code == TSDB_CODE_TSC_ACTION_IN_PROGRESS) {
-        taosReleaseRef(tscObjRef, pSql->self);
+        taosReleaseRef(tscObjRef, handle);
         rpcFreeCont(rpcMsg->pCont);
         return;
       }
@@ -418,13 +422,15 @@ void tscProcessMsgFromServer(SRpcMsg *rpcMsg, SRpcEpSet *pEpSet) {
     (*pSql->fp)(pSql->param, pSql, rpcMsg->code);
   }
 
-  taosReleaseRef(tscObjRef, pSql->self);
+  
 
   if (shouldFree) { // in case of table-meta/vgrouplist query, automatically free it
-    taosRemoveRef(tscObjRef, pSql->self);
+    taosRemoveRef(tscObjRef, handle);
     tscDebug("%p sqlObj is automatically freed", pSql); 
   }
 
+  taosReleaseRef(tscObjRef, handle);
+
   rpcFreeCont(rpcMsg->pCont);
 }
 
diff --git a/src/client/src/tscSql.c b/src/client/src/tscSql.c
index 36146a49b9a2f1b9e59a1cc69ebeda4ef983ef64..448eea16bf5a529f489b59ced9a9f32c513338eb 100644
--- a/src/client/src/tscSql.c
+++ b/src/client/src/tscSql.c
@@ -90,9 +90,11 @@ static SSqlObj *taosConnectImpl(const char *ip, const char *user, const char *pa
   } else {
     if (tscSetMgmtEpSetFromCfg(tsFirst, tsSecond, &corMgmtEpSet) < 0) return NULL;
   }
+  char rpcKey[512] = {0};
+  snprintf(rpcKey, sizeof(rpcKey), "%s:%s:%s:%d", user, pass, ip, port);
  
-  void *pDnodeConn = NULL;
-  if (tscInitRpc(user, secretEncrypt, &pDnodeConn) != 0) {
+  void *pRpcObj = NULL;
+  if (tscAcquireRpc(rpcKey, user, secretEncrypt, &pRpcObj) != 0) {
     terrno = TSDB_CODE_RPC_NETWORK_UNAVAIL;
     return NULL;
   }
@@ -100,23 +102,21 @@ static SSqlObj *taosConnectImpl(const char *ip, const char *user, const char *pa
   STscObj *pObj = (STscObj *)calloc(1, sizeof(STscObj));
   if (NULL == pObj) {
     terrno = TSDB_CODE_TSC_OUT_OF_MEMORY;
-    rpcClose(pDnodeConn);
+    tscReleaseRpc(pRpcObj);
     return NULL;
   }
-  // set up tscObj's mgmtEpSet
-  pObj->tscCorMgmtEpSet = (SRpcCorEpSet *)malloc(sizeof(SRpcCorEpSet));
-  if (NULL == pObj->tscCorMgmtEpSet) {
+
+  pObj->tscCorMgmtEpSet = malloc(sizeof(SRpcCorEpSet));
+  if (pObj->tscCorMgmtEpSet == NULL) {
     terrno = TSDB_CODE_TSC_OUT_OF_MEMORY;
-    rpcClose(pDnodeConn);
-    free(pObj->tscCorMgmtEpSet);
+    tscReleaseRpc(pRpcObj);
     free(pObj);
     return NULL;
   }
-  memcpy(pObj->tscCorMgmtEpSet, &corMgmtEpSet, sizeof(SRpcCorEpSet));
-
-  pObj->signature = pObj;
-  pObj->pDnodeConn = pDnodeConn;
+  memcpy(pObj->tscCorMgmtEpSet, &corMgmtEpSet, sizeof(corMgmtEpSet));
   
+  pObj->signature = pObj;
+  pObj->pRpcObj = (SRpcObj *)pRpcObj;
   tstrncpy(pObj->user, user, sizeof(pObj->user));
   secretEncryptLen = MIN(secretEncryptLen, sizeof(pObj->pass));
   memcpy(pObj->pass, secretEncrypt, secretEncryptLen);
@@ -126,8 +126,7 @@ static SSqlObj *taosConnectImpl(const char *ip, const char *user, const char *pa
     /* db name is too long */
     if (len >= TSDB_DB_NAME_LEN) {
       terrno = TSDB_CODE_TSC_INVALID_DB_LENGTH;
-      rpcClose(pDnodeConn);
-      free(pObj->tscCorMgmtEpSet);
+      tscReleaseRpc(pRpcObj);
       free(pObj);
       return NULL;
     }
@@ -144,8 +143,7 @@ static SSqlObj *taosConnectImpl(const char *ip, const char *user, const char *pa
   SSqlObj *pSql = (SSqlObj *)calloc(1, sizeof(SSqlObj));
   if (NULL == pSql) {
     terrno = TSDB_CODE_TSC_OUT_OF_MEMORY;
-    rpcClose(pDnodeConn);
-    free(pObj->tscCorMgmtEpSet);
+    tscReleaseRpc(pRpcObj);
     free(pObj);
     return NULL;
   }
@@ -161,9 +159,8 @@ static SSqlObj *taosConnectImpl(const char *ip, const char *user, const char *pa
 
   if (TSDB_CODE_SUCCESS != tscAllocPayload(&pSql->cmd, TSDB_DEFAULT_PAYLOAD_SIZE)) {
     terrno = TSDB_CODE_TSC_OUT_OF_MEMORY;
-    rpcClose(pDnodeConn);
+    tscReleaseRpc(pRpcObj);
     free(pSql);
-    free(pObj->tscCorMgmtEpSet);
     free(pObj);
     return NULL;
   }
@@ -202,7 +199,7 @@ TAOS *taos_connect_internal(const char *ip, const char *user, const char *pass,
       return NULL;
     }
     
-    tscDebug("%p DB connection is opening, dnodeConn:%p", pObj, pObj->pDnodeConn);
+    tscDebug("%p DB connection is opening, rpcObj: %p, dnodeConn:%p", pObj, pObj->pRpcObj, pObj->pRpcObj->pDnodeConn);
     taos_free_result(pSql);
   
     // version compare only requires the first 3 segments of the version string
@@ -279,7 +276,7 @@ void taos_close(TAOS *taos) {
     return;
   }
 
-  tscDebug("%p try to free tscObj and close dnodeConn:%p", pObj, pObj->pDnodeConn);
+  tscDebug("%p try to free tscObj", pObj);
   if (pObj->signature != pObj) {
     tscDebug("%p already closed or invalid tscObj", pObj);
     return;
@@ -303,7 +300,7 @@ void taos_close(TAOS *taos) {
     }
   }
 
-  tscDebug("%p all sqlObj are freed, free tscObj and close dnodeConn:%p", pObj, pObj->pDnodeConn);
+  tscDebug("%p all sqlObj are freed, free tscObj", pObj);
   taosRemoveRef(tscRefId, pObj->rid);
 }
 
diff --git a/src/client/src/tscSystem.c b/src/client/src/tscSystem.c
index dd0f248b85452342fb567357ba9346ab71754dfc..62ae2cd7098b74a5b5c9d024a116d1f47851c6cd 100644
--- a/src/client/src/tscSystem.c
+++ b/src/client/src/tscSystem.c
@@ -43,41 +43,74 @@ void      *tscTmr;
 void      *tscQhandle;
 int32_t    tscRefId = -1;
 int32_t    tscNumOfObj = 0;         // number of sqlObj in current process.
-
 static void  *tscCheckDiskUsageTmr;
+void      *tscRpcCache;            // cache to keep rpc obj
+int32_t   tscNumOfThreads = 1;     // num of rpc threads  
+static    pthread_mutex_t rpcObjMutex; // mutex to protect open the rpc obj concurrently 
 static pthread_once_t tscinit = PTHREAD_ONCE_INIT;
 
 void tscCheckDiskUsage(void *UNUSED_PARAM(para), void* UNUSED_PARAM(param)) {
   taosGetDisk();
   taosTmrReset(tscCheckDiskUsage, 1000, NULL, tscTmr, &tscCheckDiskUsageTmr);
 }
+void tscFreeRpcObj(void *param) {
+  assert(param);
+  SRpcObj *pRpcObj = (SRpcObj *)(param);
+  tscDebug("free rpcObj:%p and free pDnodeConn: %p", pRpcObj, pRpcObj->pDnodeConn);
+  rpcClose(pRpcObj->pDnodeConn);
+}
 
-int32_t tscInitRpc(const char *user, const char *secretEncrypt, void **pDnodeConn) {
-  SRpcInit rpcInit;
-
-  if (*pDnodeConn == NULL) {
-    memset(&rpcInit, 0, sizeof(rpcInit));
-    rpcInit.localPort = 0;
-    rpcInit.label = "TSC";
-    rpcInit.numOfThreads = 1;  // every DB connection has only one thread
-    rpcInit.cfp = tscProcessMsgFromServer;
-    rpcInit.sessions = tsMaxConnections;
-    rpcInit.connType = TAOS_CONN_CLIENT;
-    rpcInit.user = (char *)user;
-    rpcInit.idleTime = 2000;
-    rpcInit.ckey = "key";
-    rpcInit.spi = 1;
-    rpcInit.secret = (char *)secretEncrypt;
-
-    *pDnodeConn = rpcOpen(&rpcInit);
-    if (*pDnodeConn == NULL) {
-      tscError("failed to init connection to TDengine");
-      return -1;
-    } else {
-      tscDebug("dnodeConn:%p is created, user:%s", *pDnodeConn, user);
-    }
+void tscReleaseRpc(void *param)  {
+  if (param == NULL) {
+    return;
   }
+  pthread_mutex_lock(&rpcObjMutex);
+  taosCacheRelease(tscRpcCache, (void *)&param, true); 
+  pthread_mutex_unlock(&rpcObjMutex);
+} 
 
+int32_t tscAcquireRpc(const char *key, const char *user, const char *secretEncrypt, void **ppRpcObj) {
+  pthread_mutex_lock(&rpcObjMutex);
+
+  SRpcObj *pRpcObj = (SRpcObj *)taosCacheAcquireByKey(tscRpcCache, key, strlen(key));
+  if (pRpcObj != NULL) {
+    *ppRpcObj = pRpcObj;   
+    pthread_mutex_unlock(&rpcObjMutex);
+    return 0;
+  } 
+
+  SRpcInit rpcInit;
+  memset(&rpcInit, 0, sizeof(rpcInit));
+  rpcInit.localPort = 0;
+  rpcInit.label = "TSC";
+  rpcInit.numOfThreads = tscNumOfThreads * 2;    
+  rpcInit.cfp = tscProcessMsgFromServer;
+  rpcInit.sessions = tsMaxConnections;
+  rpcInit.connType = TAOS_CONN_CLIENT;
+  rpcInit.user = (char *)user;
+  rpcInit.idleTime = 2000; 
+  rpcInit.ckey = "key"; 
+  rpcInit.spi = 1; 
+  rpcInit.secret = (char *)secretEncrypt;
+
+  SRpcObj rpcObj;
+  memset(&rpcObj, 0, sizeof(rpcObj));
+  strncpy(rpcObj.key, key, strlen(key));
+  rpcObj.pDnodeConn = rpcOpen(&rpcInit);
+  if (rpcObj.pDnodeConn == NULL) {
+    pthread_mutex_unlock(&rpcObjMutex);
+    tscError("failed to init connection to TDengine");
+    return -1;
+  } 
+  pRpcObj = taosCachePut(tscRpcCache, rpcObj.key, strlen(rpcObj.key), &rpcObj, sizeof(rpcObj), 1000*10);   
+  if (pRpcObj == NULL) {
+    rpcClose(rpcObj.pDnodeConn);
+    pthread_mutex_unlock(&rpcObjMutex);
+    return -1;
+  } 
+
+  *ppRpcObj  = pRpcObj;
+  pthread_mutex_unlock(&rpcObjMutex);
   return 0;
 }
 
@@ -118,7 +151,7 @@ void taos_init_imp(void) {
   int queueSize = tsMaxConnections*2;
 
   double factor = (tscEmbedded == 0)? 2.0:4.0;
-  int32_t tscNumOfThreads = (int)(tsNumOfCores * tsNumOfThreadsPerCore / factor);
+  tscNumOfThreads = (int)(tsNumOfCores * tsNumOfThreadsPerCore / factor);
   if (tscNumOfThreads < 2) {
     tscNumOfThreads = 2;
   }
@@ -140,6 +173,10 @@ void taos_init_imp(void) {
     tscTableMetaInfo = taosHashInit(1024, taosGetDefaultHashFunction(TSDB_DATA_TYPE_BINARY), true, HASH_ENTRY_LOCK);
     tscDebug("TableMeta:%p", tscTableMetaInfo);
   }
+   
+  int refreshTime = 5;
+  tscRpcCache = taosCacheInit(TSDB_DATA_TYPE_BINARY, refreshTime, true, tscFreeRpcObj, "rpcObj");
+  pthread_mutex_init(&rpcObjMutex, NULL);
 
   tscRefId = taosOpenRef(200, tscCloseTscObj);
 
@@ -179,11 +216,19 @@ void taos_cleanup(void) {
   taosCloseRef(id);
 
   taosCleanupKeywordsTable();
-  taosCloseLog();
+
+  p = tscRpcCache; 
+  tscRpcCache = NULL;
+  
+  if (p != NULL) {
+    taosCacheCleanup(p); 
+    pthread_mutex_destroy(&rpcObjMutex);
+  }
 
   if (tscEmbedded == 0) {
     rpcCleanup();
-  }
+    taosCloseLog();
+  };
 
   p = tscTmr;
   tscTmr = NULL;
diff --git a/src/client/src/tscUtil.c b/src/client/src/tscUtil.c
index 824fff574e2fd1160eaa2cef1d6edc0869ea2a67..83d9dd805cb006ad4728f2adadffbabc7da128f6 100644
--- a/src/client/src/tscUtil.c
+++ b/src/client/src/tscUtil.c
@@ -32,6 +32,14 @@
 static void freeQueryInfoImpl(SQueryInfo* pQueryInfo);
 static void clearAllTableMetaInfo(SQueryInfo* pQueryInfo);
 
+static void tscStrToLower(char *str, int32_t n) {
+  if (str == NULL || n <= 0) { return;}
+  for (int32_t i = 0; i < n; i++) {
+    if (str[i] >= 'A' && str[i] <= 'Z') {
+        str[i] -= ('A' - 'a');
+    }
+  }
+}
 SCond* tsGetSTableQueryCond(STagCond* pTagCond, uint64_t uid) {
   if (pTagCond->pCond == NULL) {
     return NULL;
@@ -447,7 +455,6 @@ void tscFreeRegisteredSqlObj(void *pSql) {
 
   SSqlObj* p = *(SSqlObj**)pSql;
   STscObj* pTscObj = p->pTscObj;
-
   assert(RID_VALID(p->self));
 
   int32_t num   = atomic_sub_fetch_32(&pTscObj->numOfObj, 1);
@@ -898,16 +905,10 @@ void tscCloseTscObj(void *param) {
   pObj->signature = NULL;
   taosTmrStopA(&(pObj->pTimer));
 
-  void* p = pObj->pDnodeConn;
-  if (pObj->pDnodeConn != NULL) {
-    rpcClose(pObj->pDnodeConn);
-    pObj->pDnodeConn = NULL;
-  }
-
   tfree(pObj->tscCorMgmtEpSet);
+  tscReleaseRpc(pObj->pRpcObj);
   pthread_mutex_destroy(&pObj->mutex);
 
-  tscDebug("%p DB connection is closed, dnodeConn:%p", pObj, p);
   tfree(pObj);
 }
 
@@ -1420,9 +1421,11 @@ int32_t tscValidateName(SStrToken* pToken) {
   char* sep = strnchr(pToken->z, TS_PATH_DELIMITER[0], pToken->n, true);
   if (sep == NULL) {  // single part
     if (pToken->type == TK_STRING) {
+       
       strdequote(pToken->z);
+      tscStrToLower(pToken->z, pToken->n);
       pToken->n = (uint32_t)strtrim(pToken->z);
-
+       
       int len = tSQLGetToken(pToken->z, &pToken->type);
 
       // single token, validate it
@@ -1474,7 +1477,7 @@ int32_t tscValidateName(SStrToken* pToken) {
     if (pToken->type == TK_STRING && validateQuoteToken(pToken) != TSDB_CODE_SUCCESS) {
       return TSDB_CODE_TSC_INVALID_SQL;
     }
-
+    
     // re-build the whole name string
     if (pStr[firstPartLen] == TS_PATH_DELIMITER[0]) {
       // first part do not have quote do nothing
@@ -1486,6 +1489,8 @@ int32_t tscValidateName(SStrToken* pToken) {
     }
     pToken->n += (firstPartLen + sizeof(TS_PATH_DELIMITER[0]));
     pToken->z = pStr;
+
+    tscStrToLower(pToken->z,pToken->n);
   }
 
   return TSDB_CODE_SUCCESS;
diff --git a/src/common/inc/tglobal.h b/src/common/inc/tglobal.h
index 284e71801603e8184f14e96bb42b4d1896060780..9b498e8bd2ab9e8bf2f31f5a91e6d881544a34f9 100644
--- a/src/common/inc/tglobal.h
+++ b/src/common/inc/tglobal.h
@@ -57,7 +57,8 @@ extern int32_t  tsCompressMsgSize;
 extern char     tsTempDir[];
 
 //query buffer management
-extern int32_t  tsQueryBufferSize;      // maximum allowed usage buffer for each data node during query processing
+extern int32_t  tsQueryBufferSize;      // maximum allowed usage buffer size in MB for each data node during query processing
+extern int64_t  tsQueryBufferSizeBytes; // maximum allowed usage buffer size in byte for each data node during query processing
 extern int32_t  tsRetrieveBlockingModel;// retrieve threads will be blocked
 
 extern int8_t   tsKeepOriginalColumnName;
diff --git a/src/common/src/tglobal.c b/src/common/src/tglobal.c
index 4a9b4c3e4357679e034fbda8ae296ed7b3589483..a2d02be683cd9b78e518d9630d604d8874035d68 100644
--- a/src/common/src/tglobal.c
+++ b/src/common/src/tglobal.c
@@ -105,6 +105,7 @@ int64_t tsMaxRetentWindow = 24 * 3600L;  // maximum time window tolerance
 // 0  no query allowed, queries are disabled
 // positive value (in MB)
 int32_t tsQueryBufferSize = -1;
+int64_t tsQueryBufferSizeBytes = -1;
 
 // in retrieve blocking model, the retrieve threads will wait for the completion of the query processing.
 int32_t tsRetrieveBlockingModel = 0;
@@ -283,7 +284,7 @@ bool taosCfgDynamicOptions(char *msg) {
     int32_t cfgLen = (int32_t)strlen(cfg->option);
     if (cfgLen != olen) continue;
     if (strncasecmp(option, cfg->option, olen) != 0) continue;
-    if (cfg->valType != TAOS_CFG_VTYPE_INT32) {
+    if (cfg->valType == TAOS_CFG_VTYPE_INT32) {
       *((int32_t *)cfg->ptr) = vint;
     } else {
       *((int8_t *)cfg->ptr) = (int8_t)vint;
@@ -1488,6 +1489,10 @@ int32_t taosCheckGlobalCfg() {
   tsSyncPort = tsServerPort + TSDB_PORT_SYNC;
   tsHttpPort = tsServerPort + TSDB_PORT_HTTP;
 
+  if (tsQueryBufferSize >= 0) {
+    tsQueryBufferSizeBytes = tsQueryBufferSize * 1048576UL;
+  }
+
   taosPrintGlobalCfg();
 
   return 0;
diff --git a/src/common/src/ttypes.c b/src/common/src/ttypes.c
index 0d5910ea3815eb36b2aa15d205dfcf0e7148ae72..6fa27a029bfd5356cca3e34dffe8d3018ade9fd8 100644
--- a/src/common/src/ttypes.c
+++ b/src/common/src/ttypes.c
@@ -632,7 +632,7 @@ int32_t tStrToInteger(const char* z, int16_t type, int32_t n, int64_t* value, bo
   }
 
   // the string may be overflow according to errno
-  *value = issigned? strtoll(z, &endPtr, radix):strtoul(z, &endPtr, radix);
+  *value = issigned? strtoll(z, &endPtr, radix):strtoull(z, &endPtr, radix);
 
   // not a valid integer number, return error
   if (endPtr - z != n || errno == ERANGE) {
diff --git a/src/cq/src/cqMain.c b/src/cq/src/cqMain.c
index 5f1fecc49470c29dbd405b73c8773d491c7d65c4..a5de27d7fc0cc3922456f5311834f2bd812f7a57 100644
--- a/src/cq/src/cqMain.c
+++ b/src/cq/src/cqMain.c
@@ -50,10 +50,13 @@ typedef struct {
   void    *dbConn;
   void    *tmrCtrl;
   pthread_mutex_t mutex;
+  int32_t delete;
+  int32_t cqObjNum;
 } SCqContext;
 
 typedef struct SCqObj {
   tmr_h          tmrId;
+  int64_t        rid;
   uint64_t       uid;
   int32_t        tid;      // table ID
   int32_t        rowSize;  // bytes of a row
@@ -69,6 +72,84 @@ typedef struct SCqObj {
 static void cqProcessStreamRes(void *param, TAOS_RES *tres, TAOS_ROW row); 
 static void cqCreateStream(SCqContext *pContext, SCqObj *pObj);
 
+int32_t    cqObjRef = -1;
+
+void cqRmFromList(SCqObj *pObj) {
+  //LOCK in caller
+
+  SCqContext *pContext = pObj->pContext;
+
+  if (pObj->prev) {
+    pObj->prev->next = pObj->next;
+  } else {
+    pContext->pHead = pObj->next;
+  }
+
+  if (pObj->next) {
+    pObj->next->prev = pObj->prev;
+  }
+
+}
+
+void cqFree(void *handle) {
+  if (tsEnableStream == 0) {
+    return;
+  }
+  SCqObj *pObj = handle;
+  SCqContext *pContext = pObj->pContext;
+  int32_t delete = 0;
+
+  pthread_mutex_lock(&pContext->mutex);
+  
+  // free the resources associated
+  if (pObj->pStream) {
+    taos_close_stream(pObj->pStream);
+    pObj->pStream = NULL;
+  } else {
+    taosTmrStop(pObj->tmrId);
+    pObj->tmrId = 0;
+  }
+
+  cInfo("vgId:%d, id:%d CQ:%s is dropped", pContext->vgId, pObj->tid, pObj->sqlStr); 
+  tdFreeSchema(pObj->pSchema);
+  free(pObj->dstTable);
+  free(pObj->sqlStr);
+  free(pObj);
+
+  pContext->cqObjNum--;
+
+  if (pContext->cqObjNum <= 0 && pContext->delete) {
+    delete = 1;
+  }
+
+  pthread_mutex_unlock(&pContext->mutex);
+
+  if (delete) {
+    pthread_mutex_unlock(&pContext->mutex);
+    
+    pthread_mutex_destroy(&pContext->mutex);
+    
+    taosTmrCleanUp(pContext->tmrCtrl);
+    pContext->tmrCtrl = NULL;
+    
+    cDebug("vgId:%d, CQ is closed", pContext->vgId);
+    free(pContext);
+  }
+}
+
+
+void cqCreateRef() {
+  int32_t ref = atomic_load_32(&cqObjRef);
+  if (ref == -1) {
+    ref = taosOpenRef(4096, cqFree);
+
+    if (atomic_val_compare_exchange_32(&cqObjRef, -1, ref) != -1) {
+      taosCloseRef(ref);
+    }  
+  }
+}
+
+
 void *cqOpen(void *ahandle, const SCqCfg *pCfg) {
   if (tsEnableStream == 0) {
     return NULL;
@@ -79,6 +160,8 @@ void *cqOpen(void *ahandle, const SCqCfg *pCfg) {
     return NULL;
   }
 
+  cqCreateRef();
+
   pContext->tmrCtrl = taosTmrInit(0, 0, 0, "CQ");
 
   tstrncpy(pContext->user, pCfg->user, sizeof(pContext->user));
@@ -97,6 +180,7 @@ void *cqOpen(void *ahandle, const SCqCfg *pCfg) {
 
   pthread_mutex_init(&pContext->mutex, NULL);
 
+
   cDebug("vgId:%d, CQ is opened", pContext->vgId);
 
   return pContext;
@@ -109,30 +193,30 @@ void cqClose(void *handle) {
   SCqContext *pContext = handle;
   if (handle == NULL) return;
 
+  pContext->delete = 1;
+  
   // stop all CQs
   cqStop(pContext);
 
-  // free all resources
-  pthread_mutex_lock(&pContext->mutex);
-
-  SCqObj *pObj = pContext->pHead;
-  while (pObj) {
-    SCqObj *pTemp = pObj;
-    pObj = pObj->next;
-    tdFreeSchema(pTemp->pSchema);
-    tfree(pTemp->sqlStr);
-    free(pTemp);
-  } 
-  
-  pthread_mutex_unlock(&pContext->mutex);
+  int64_t rid = 0;
 
-  pthread_mutex_destroy(&pContext->mutex);
+  while (1) {
+    pthread_mutex_lock(&pContext->mutex);
 
-  taosTmrCleanUp(pContext->tmrCtrl);
-  pContext->tmrCtrl = NULL;
+    SCqObj *pObj = pContext->pHead;
+    if (pObj) {
+      cqRmFromList(pObj);
 
-  cDebug("vgId:%d, CQ is closed", pContext->vgId);
-  free(pContext);
+      rid = pObj->rid;
+    } else {      
+      pthread_mutex_unlock(&pContext->mutex);
+      break;
+    }
+    
+    pthread_mutex_unlock(&pContext->mutex);
+    
+    taosRemoveRef(cqObjRef, rid);
+  }
 }
 
 void cqStart(void *handle) {
@@ -191,7 +275,8 @@ void *cqCreate(void *handle, uint64_t uid, int32_t sid, const char* dstTable, ch
     return NULL;
   }
   SCqContext *pContext = handle;
-
+  int64_t rid = 0;
+  
   SCqObj *pObj = calloc(sizeof(SCqObj), 1);
   if (pObj == NULL) return NULL;
 
@@ -213,32 +298,36 @@ void *cqCreate(void *handle, uint64_t uid, int32_t sid, const char* dstTable, ch
   if (pContext->pHead) pContext->pHead->prev = pObj;
   pContext->pHead = pObj;
 
+  pContext->cqObjNum++;
+
+  pObj->rid = taosAddRef(cqObjRef, pObj);
+
   cqCreateStream(pContext, pObj);
 
+  rid = pObj->rid;
+
   pthread_mutex_unlock(&pContext->mutex);
 
-  return pObj;
+
+  return (void *)rid;
 }
 
 void cqDrop(void *handle) {
   if (tsEnableStream == 0) {
     return;
   }
-  SCqObj *pObj = handle;
-  SCqContext *pContext = pObj->pContext;
-
-  pthread_mutex_lock(&pContext->mutex);
 
-  if (pObj->prev) {
-    pObj->prev->next = pObj->next;
-  } else {
-    pContext->pHead = pObj->next;
-  }
-
-  if (pObj->next) {
-    pObj->next->prev = pObj->prev;
+  SCqObj* pObj = (SCqObj*)taosAcquireRef(cqObjRef, (int64_t)handle);
+  if (pObj == NULL) {
+    return;
   }
+  
+  SCqContext *pContext = pObj->pContext;
+  
+  pthread_mutex_lock(&pContext->mutex);
 
+  cqRmFromList(pObj);
+  
   // free the resources associated
   if (pObj->pStream) {
     taos_close_stream(pObj->pStream);
@@ -248,17 +337,18 @@ void cqDrop(void *handle) {
     pObj->tmrId = 0;
   }
 
-  cInfo("vgId:%d, id:%d CQ:%s is dropped", pContext->vgId, pObj->tid, pObj->sqlStr); 
-  tdFreeSchema(pObj->pSchema);
-  free(pObj->dstTable);
-  free(pObj->sqlStr);
-  free(pObj);
-
   pthread_mutex_unlock(&pContext->mutex);
+
+  taosRemoveRef(cqObjRef, (int64_t)handle);
+  taosReleaseRef(cqObjRef, (int64_t)handle);
 }
 
 static void doCreateStream(void *param, TAOS_RES *result, int32_t code) {
-  SCqObj* pObj = (SCqObj*)param;
+  SCqObj* pObj = (SCqObj*)taosAcquireRef(cqObjRef, (int64_t)param);
+  if (pObj == NULL) {
+    return;
+  }
+  
   SCqContext* pContext = pObj->pContext;
   SSqlObj* pSql = (SSqlObj*)result;
   if (atomic_val_compare_exchange_ptr(&(pContext->dbConn), NULL, pSql->pTscObj) != NULL) {
@@ -267,10 +357,16 @@ static void doCreateStream(void *param, TAOS_RES *result, int32_t code) {
   pthread_mutex_lock(&pContext->mutex);
   cqCreateStream(pContext, pObj);
   pthread_mutex_unlock(&pContext->mutex);
+
+  taosReleaseRef(cqObjRef, (int64_t)param);
 }
 
 static void cqProcessCreateTimer(void *param, void *tmrId) {
-  SCqObj* pObj = (SCqObj*)param;
+  SCqObj* pObj = (SCqObj*)taosAcquireRef(cqObjRef, (int64_t)param);
+  if (pObj == NULL) {
+    return;
+  }
+  
   SCqContext* pContext = pObj->pContext;
 
   if (pContext->dbConn == NULL) {
@@ -281,6 +377,8 @@ static void cqProcessCreateTimer(void *param, void *tmrId) {
     cqCreateStream(pContext, pObj);
     pthread_mutex_unlock(&pContext->mutex);
   }
+
+  taosReleaseRef(cqObjRef, (int64_t)param);
 }
 
 static void cqCreateStream(SCqContext *pContext, SCqObj *pObj) {
@@ -288,13 +386,13 @@ static void cqCreateStream(SCqContext *pContext, SCqObj *pObj) {
 
   if (pContext->dbConn == NULL) {
     cDebug("vgId:%d, create dbConn after 1000 ms", pContext->vgId);
-    pObj->tmrId = taosTmrStart(cqProcessCreateTimer, 1000, pObj, pContext->tmrCtrl);
+    pObj->tmrId = taosTmrStart(cqProcessCreateTimer, 1000, (void *)pObj->rid, pContext->tmrCtrl);
     return;
   }
   pObj->tmrId = 0;
 
   if (pObj->pStream == NULL) {
-    pObj->pStream = taos_open_stream(pContext->dbConn, pObj->sqlStr, cqProcessStreamRes, 0, pObj, NULL);
+    pObj->pStream = taos_open_stream(pContext->dbConn, pObj->sqlStr, cqProcessStreamRes, 0, (void *)pObj->rid, NULL);
 
     // TODO the pObj->pStream may be released if error happens
     if (pObj->pStream) {
@@ -308,18 +406,28 @@ static void cqCreateStream(SCqContext *pContext, SCqObj *pObj) {
 }
 
 static void cqProcessStreamRes(void *param, TAOS_RES *tres, TAOS_ROW row) {
-  SCqObj *pObj = (SCqObj *)param;
+  SCqObj* pObj = (SCqObj*)taosAcquireRef(cqObjRef, (int64_t)param);
+  if (pObj == NULL) {
+    return;
+  }
+  
   if (tres == NULL && row == NULL) {
     taos_close_stream(pObj->pStream);
 
     pObj->pStream = NULL;
+
+    taosReleaseRef(cqObjRef, (int64_t)param);
+
     return;
   }
 
   SCqContext *pContext = pObj->pContext;
   STSchema   *pSchema = pObj->pSchema;
-  if (pObj->pStream == NULL) return;
-
+  if (pObj->pStream == NULL) {    
+    taosReleaseRef(cqObjRef, (int64_t)param);
+    return;
+  }
+  
   cDebug("vgId:%d, id:%d CQ:%s stream result is ready", pContext->vgId, pObj->tid, pObj->sqlStr);
 
   int32_t size = sizeof(SWalHead) + sizeof(SSubmitMsg) + sizeof(SSubmitBlk) + TD_DATA_ROW_HEAD_SIZE + pObj->rowSize;
@@ -370,5 +478,7 @@ static void cqProcessStreamRes(void *param, TAOS_RES *tres, TAOS_ROW row) {
   // write into vnode write queue
   pContext->cqWrite(pContext->vgId, pHead, TAOS_QTYPE_CQ, NULL);
   free(buffer);
+  
+  taosReleaseRef(cqObjRef, (int64_t)param);
 }
 
diff --git a/src/dnode/src/dnodeCfg.c b/src/dnode/src/dnodeCfg.c
index e008d2fa0d82ea65c0c60ce31d6064de1790f978..fd5956b37f28603893b43ca91f8cfd1177dccad2 100644
--- a/src/dnode/src/dnodeCfg.c
+++ b/src/dnode/src/dnodeCfg.c
@@ -156,7 +156,7 @@ static int32_t dnodeWriteCfg() {
   len += snprintf(content + len, maxLen - len, "}\n");
 
   fwrite(content, 1, len, fp);
-  fflush(fp);
+  fsync(fileno(fp));
   fclose(fp);
   free(content);
   terrno = 0;
diff --git a/src/dnode/src/dnodeEps.c b/src/dnode/src/dnodeEps.c
index 1e05c696ce28d3594349ca1e5134550687017893..9554651776ad0e9c961a3d15955491b224d869bf 100644
--- a/src/dnode/src/dnodeEps.c
+++ b/src/dnode/src/dnodeEps.c
@@ -277,7 +277,7 @@ static int32_t dnodeWriteEps() {
   len += snprintf(content + len, maxLen - len, "}\n");
 
   fwrite(content, 1, len, fp);
-  fflush(fp);
+  fsync(fileno(fp));
   fclose(fp);
   free(content);
   terrno = 0;
diff --git a/src/dnode/src/dnodeMInfos.c b/src/dnode/src/dnodeMInfos.c
index 884924f113c3d0131bf0627a3c2563edbf819ec4..0dca116d84a8267231acba686018cf6c07ae15e0 100644
--- a/src/dnode/src/dnodeMInfos.c
+++ b/src/dnode/src/dnodeMInfos.c
@@ -286,7 +286,7 @@ static int32_t dnodeWriteMInfos() {
   len += snprintf(content + len, maxLen - len, "}\n");
 
   fwrite(content, 1, len, fp);
-  fflush(fp);
+  fsync(fileno(fp));
   fclose(fp);
   free(content);
   terrno = 0;
diff --git a/src/mnode/src/mnodeUser.c b/src/mnode/src/mnodeUser.c
index d12e49e3cea2c71e517af5103d810dfa71faf370..55ee39b6bceb7a3d5ebc8838e1a9a2151ccb6c3d 100644
--- a/src/mnode/src/mnodeUser.c
+++ b/src/mnode/src/mnodeUser.c
@@ -123,7 +123,7 @@ static void mnodePrintUserAuth() {
     mnodeDecUserRef(pUser);
   }
 
-  fflush(fp);
+  fsync(fileno(fp));
   fclose(fp);
 }
 
diff --git a/src/os/src/darwin/darwinSysInfo.c b/src/os/src/darwin/darwinSysInfo.c
index 0eb784e9f052233986a13590a2c56be4de0e6e8e..5b42b6b0f69e4a5f161ca52a3afb97c934196ba8 100644
--- a/src/os/src/darwin/darwinSysInfo.c
+++ b/src/os/src/darwin/darwinSysInfo.c
@@ -18,6 +18,9 @@
 #include "tconfig.h"
 #include "tglobal.h"
 #include "tulog.h"
+#include <errno.h>
+#include <libproc.h>
+
 
 static void taosGetSystemTimezone() {
   // get and set default timezone
@@ -103,8 +106,18 @@ int taosSystem(const char *cmd) {
 
 void taosSetCoreDump() {}
 
+char cmdline[1024];
+
 char *taosGetCmdlineByPID(int pid) {
-  return "[not supported yet]";
+
+  errno = 0;
+
+  if (proc_pidpath(pid, cmdline, sizeof(cmdline)) <= 0) {
+    fprintf(stderr, "PID is %d, %s", pid, strerror(errno));
+    return strerror(errno);
+  }
+
+  return cmdline;
 }
 
 bool taosGetSystemUid(char *uid) {
diff --git a/src/query/src/qExecutor.c b/src/query/src/qExecutor.c
index 6e1945407cc0e7682a884a99ea0095bdc27c7b2c..38ba6b54008bc91c83b6a3be9b74ad287b52604c 100644
--- a/src/query/src/qExecutor.c
+++ b/src/query/src/qExecutor.c
@@ -7730,15 +7730,15 @@ static int64_t getQuerySupportBufSize(size_t numOfTables) {
 
 int32_t checkForQueryBuf(size_t numOfTables) {
   int64_t t = getQuerySupportBufSize(numOfTables);
-  if (tsQueryBufferSize < 0) {
+  if (tsQueryBufferSizeBytes < 0) {
     return TSDB_CODE_SUCCESS;
-  } else if (tsQueryBufferSize > 0) {
+  } else if (tsQueryBufferSizeBytes > 0) {
 
     while(1) {
-      int64_t s = tsQueryBufferSize;
+      int64_t s = tsQueryBufferSizeBytes;
       int64_t remain = s - t;
       if (remain >= 0) {
-        if (atomic_val_compare_exchange_64(&tsQueryBufferSize, s, remain) == s) {
+        if (atomic_val_compare_exchange_64(&tsQueryBufferSizeBytes, s, remain) == s) {
           return TSDB_CODE_SUCCESS;
         }
       } else {
@@ -7752,14 +7752,14 @@ int32_t checkForQueryBuf(size_t numOfTables) {
 }
 
 void releaseQueryBuf(size_t numOfTables) {
-  if (tsQueryBufferSize <= 0) {
+  if (tsQueryBufferSizeBytes < 0) {
     return;
   }
 
   int64_t t = getQuerySupportBufSize(numOfTables);
 
   // restore value is not enough buffer available
-  atomic_add_fetch_64(&tsQueryBufferSize, t);
+  atomic_add_fetch_64(&tsQueryBufferSizeBytes, t);
 }
 
 void* qGetResultRetrieveMsg(qinfo_t qinfo) {
diff --git a/src/rpc/src/rpcTcp.c b/src/rpc/src/rpcTcp.c
index 4fe41b17099cadf37988716154f45c6dcccb3814..3295c130ddc6060b90338ce60948b4d8ee1297dc 100644
--- a/src/rpc/src/rpcTcp.c
+++ b/src/rpc/src/rpcTcp.c
@@ -48,6 +48,13 @@ typedef struct SThreadObj {
   void           *(*processData)(SRecvInfo *pPacket);
 } SThreadObj;
 
+typedef struct {
+  char    label[TSDB_LABEL_LEN];
+  int32_t index;
+  int numOfThreads;
+  SThreadObj **pThreadObj;
+} SClientObj;
+
 typedef struct {
   SOCKET      fd;
   uint32_t    ip;
@@ -116,6 +123,7 @@ void *taosInitTcpServer(uint32_t ip, uint16_t port, char *label, int numOfThread
     pThreadObj->processData = fp;
     tstrncpy(pThreadObj->label, label, sizeof(pThreadObj->label));
     pThreadObj->shandle = shandle;
+    pThreadObj->stop = false;
   }
 
   // initialize mutex, thread, fd which may fail
@@ -166,6 +174,7 @@ void *taosInitTcpServer(uint32_t ip, uint16_t port, char *label, int numOfThread
 }
 
 static void taosStopTcpThread(SThreadObj* pThreadObj) {
+  if (pThreadObj == NULL)  { return;}
   // save thread into local variable and signal thread to stop 
   pthread_t thread = pThreadObj->thread; 
   if (!taosCheckPthreadValid(thread)) {
@@ -282,68 +291,104 @@ static void *taosAcceptTcpConnection(void *arg) {
   return NULL;
 }
 
-void *taosInitTcpClient(uint32_t ip, uint16_t port, char *label, int num, void *fp, void *shandle) {
-  SThreadObj    *pThreadObj;
-  pthread_attr_t thattr;
-
-  pThreadObj = (SThreadObj *)malloc(sizeof(SThreadObj));
-  memset(pThreadObj, 0, sizeof(SThreadObj));
-  tstrncpy(pThreadObj->label, label, sizeof(pThreadObj->label));
-  pThreadObj->ip = ip;
-  pThreadObj->shandle = shandle;
-
-  if (pthread_mutex_init(&(pThreadObj->mutex), NULL) < 0) {
-    tError("%s failed to init TCP client mutex(%s)", label, strerror(errno));
-    free(pThreadObj);
+void *taosInitTcpClient(uint32_t ip, uint16_t port, char *label, int numOfThreads, void *fp, void *shandle) {
+  SClientObj *pClientObj = (SClientObj *)calloc(1, sizeof(SClientObj));
+  if (pClientObj == NULL) {
+    tError("TCP:%s no enough memory", label);
     terrno = TAOS_SYSTEM_ERROR(errno); 
     return NULL;
-  }
+  } 
 
-  pThreadObj->pollFd = (EpollFd)epoll_create(10);  // size does not matter
-  if (pThreadObj->pollFd < 0) {
-    tError("%s failed to create TCP client epoll", label);
-    free(pThreadObj);
+  tstrncpy(pClientObj->label, label, sizeof(pClientObj->label));
+  pClientObj->numOfThreads = numOfThreads;
+  pClientObj->pThreadObj = (SThreadObj **)calloc(numOfThreads, sizeof(SThreadObj*));  
+  if (pClientObj->pThreadObj == NULL) {
+    tError("TCP:%s no enough memory", label);
+    tfree(pClientObj);
     terrno = TAOS_SYSTEM_ERROR(errno); 
-    return NULL;
   }
 
-  pThreadObj->processData = fp;
-
+  int code = 0;
+  pthread_attr_t thattr;
   pthread_attr_init(&thattr);
   pthread_attr_setdetachstate(&thattr, PTHREAD_CREATE_JOINABLE);
-  int code = pthread_create(&(pThreadObj->thread), &thattr, taosProcessTcpData, (void *)(pThreadObj));
-  pthread_attr_destroy(&thattr);
-  if (code != 0) {
-    EpollClose(pThreadObj->pollFd);
-    pThreadObj->pollFd = -1;
-    free(pThreadObj);
-    terrno = TAOS_SYSTEM_ERROR(errno); 
-    tError("%s failed to create TCP read data thread(%s)", label, strerror(errno));
-    return NULL;
+
+  for (int i = 0; i < numOfThreads; ++i) {
+    SThreadObj *pThreadObj = (SThreadObj *)calloc(1, sizeof(SThreadObj));
+    if (pThreadObj == NULL) {
+      tError("TCP:%s no enough memory", label);
+      terrno = TAOS_SYSTEM_ERROR(errno); 
+      for (int j=0; j<i; ++j) free(pClientObj->pThreadObj[j]);
+      free(pClientObj);
+      pthread_attr_destroy(&thattr);
+      return NULL;
+    }
+    pClientObj->pThreadObj[i] = pThreadObj;
+    taosResetPthread(&pThreadObj->thread);
+    pThreadObj->ip      = ip;
+    pThreadObj->stop    = false;
+    tstrncpy(pThreadObj->label, label, sizeof(pThreadObj->label));
+    pThreadObj->shandle = shandle;
+    pThreadObj->processData = fp;
   }
 
-  tDebug("%s TCP client is initialized, ip:%u:%hu", label, ip, port);
+  // initialize mutex, thread, fd which may fail
+  for (int i = 0; i < numOfThreads; ++i) {
+    SThreadObj *pThreadObj = pClientObj->pThreadObj[i];
+    code = pthread_mutex_init(&(pThreadObj->mutex), NULL);
+    if (code < 0) {
+      tError("%s failed to init TCP process data mutex(%s)", label, strerror(errno));
+      break;
+    }
+
+    pThreadObj->pollFd = (int64_t)epoll_create(10);  // size does not matter
+    if (pThreadObj->pollFd < 0) {
+      tError("%s failed to create TCP epoll", label);
+      code = -1;
+      break;
+    }
 
-  return pThreadObj;
+    code = pthread_create(&(pThreadObj->thread), &thattr, taosProcessTcpData, (void *)(pThreadObj));
+    if (code != 0) {
+      tError("%s failed to create TCP process data thread(%s)", label, strerror(errno));
+      break;
+    }
+    pThreadObj->threadId = i;
+  }
+  if (code != 0) {
+    terrno = TAOS_SYSTEM_ERROR(errno); 
+    taosCleanUpTcpClient(pClientObj);
+    pClientObj = NULL;
+  } 
+  return pClientObj; 
 }
 
 void taosStopTcpClient(void *chandle) {
-  SThreadObj *pThreadObj = chandle;
-  if (pThreadObj == NULL) return;
+  SClientObj *pClientObj = chandle;
+
+  if (pClientObj == NULL) return;
 
-  tDebug ("%s TCP client is stopped", pThreadObj->label);
+  tDebug ("%s TCP client is stopped", pClientObj->label);
 }
 
 void taosCleanUpTcpClient(void *chandle) {
-  SThreadObj *pThreadObj = chandle;
-  if (pThreadObj == NULL) return;
-
-  tDebug ("%s TCP client will be cleaned up", pThreadObj->label);
-  taosStopTcpThread(pThreadObj);
+  SClientObj *pClientObj = chandle;
+  if (pClientObj == NULL) return;
+  for (int i = 0; i < pClientObj->numOfThreads; ++i) { 
+    SThreadObj *pThreadObj= pClientObj->pThreadObj[i];
+    taosStopTcpThread(pThreadObj); 
+  }
+  
+  tDebug("%s TCP client is cleaned up", pClientObj->label);
+  tfree(pClientObj->pThreadObj);
+  tfree(pClientObj);   
 }
 
 void *taosOpenTcpClientConnection(void *shandle, void *thandle, uint32_t ip, uint16_t port) {
-  SThreadObj *    pThreadObj = shandle;
+  SClientObj *    pClientObj = shandle;
+  int32_t index = atomic_load_32(&pClientObj->index) % pClientObj->numOfThreads;
+    atomic_store_32(&pClientObj->index, index + 1); 
+  SThreadObj *pThreadObj = pClientObj->pThreadObj[index];
 
   SOCKET fd = taosOpenTcpClientSocket(ip, port, pThreadObj->ip);
   if (fd <= 0) return NULL;
diff --git a/src/util/CMakeLists.txt b/src/util/CMakeLists.txt
index 92e030ad81760ed6ede1b7e53128b731b382097d..d5b1827858a0072dc9f4d46e14b9fff4c0b76aaa 100644
--- a/src/util/CMakeLists.txt
+++ b/src/util/CMakeLists.txt
@@ -3,9 +3,10 @@ PROJECT(TDengine)
 
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/rpc/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/sync/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/deps/rmonotonic/inc)
 AUX_SOURCE_DIRECTORY(src SRC)
 ADD_LIBRARY(tutil ${SRC})
-TARGET_LINK_LIBRARIES(tutil pthread osdetail lz4 z)
+TARGET_LINK_LIBRARIES(tutil pthread osdetail lz4 z rmonotonic)
 
 IF (TD_LINUX)
   TARGET_LINK_LIBRARIES(tutil m rt)
diff --git a/src/util/src/ttimer.c b/src/util/src/ttimer.c
index 015c687b3d941db3f6414d0d3d92564dd14e0fdb..6029edf5120314cf13405f69fb8e120e73d61183 100644
--- a/src/util/src/ttimer.c
+++ b/src/util/src/ttimer.c
@@ -18,6 +18,7 @@
 #include "tsched.h"
 #include "ttimer.h"
 #include "tutil.h"
+#include "monotonic.h"
 
 extern int8_t tscEmbedded;
 
@@ -186,6 +187,10 @@ static void removeTimer(uintptr_t id) {
   unlockTimerList(list);
 }
 
+static int64_t getMonotonicMs(void) {
+  return (int64_t) getMonotonicUs() / 1000;
+}
+
 static void addToWheel(tmr_obj_t* timer, uint32_t delay) {
   timerAddRef(timer);
   // select a wheel for the timer, we are not an accurate timer,
@@ -201,7 +206,7 @@ static void addToWheel(tmr_obj_t* timer, uint32_t delay) {
 
   time_wheel_t* wheel = wheels + timer->wheel;
   timer->prev = NULL;
-  timer->expireAt = taosGetTimestampMs() + delay;
+  timer->expireAt = getMonotonicMs() + delay;
 
   pthread_mutex_lock(&wheel->mutex);
 
@@ -334,7 +339,7 @@ tmr_h taosTmrStart(TAOS_TMR_CALLBACK fp, int mseconds, void* param, void* handle
 }
 
 static void taosTimerLoopFunc(int signo) {
-  int64_t now = taosGetTimestampMs();
+  int64_t now = getMonotonicMs();
 
   for (int i = 0; i < tListLen(wheels); i++) {
     // `expried` is a temporary expire list.
@@ -501,7 +506,7 @@ static void taosTmrModuleInit(void) {
 
   pthread_mutex_init(&tmrCtrlMutex, NULL);
 
-  int64_t now = taosGetTimestampMs();
+  int64_t now = getMonotonicMs();
   for (int i = 0; i < tListLen(wheels); i++) {
     time_wheel_t* wheel = wheels + i;
     if (pthread_mutex_init(&wheel->mutex, NULL) != 0) {
@@ -532,6 +537,8 @@ static void taosTmrModuleInit(void) {
 }
 
 void* taosTmrInit(int maxNumOfTmrs, int resolution, int longest, const char* label) {
+  tmrInfo("ttimer monotonic clock source:%s", monotonicInit());
+
   pthread_once(&tmrModuleInit, taosTmrModuleInit);
 
   pthread_mutex_lock(&tmrCtrlMutex);
diff --git a/src/vnode/src/vnodeCfg.c b/src/vnode/src/vnodeCfg.c
index 1ea774afaec92218408c5115ee6ee43e67836efd..9b7916c8bd3b4c5878b0edc3431802b3ed7cd4f6 100644
--- a/src/vnode/src/vnodeCfg.c
+++ b/src/vnode/src/vnodeCfg.c
@@ -341,7 +341,7 @@ int32_t vnodeWriteCfg(SCreateVnodeMsg *pMsg) {
   len += snprintf(content + len, maxLen - len, "}\n");
 
   fwrite(content, 1, len, fp);
-  fflush(fp);
+  fsync(fileno(fp));
   fclose(fp);
   free(content);
   terrno = 0;
diff --git a/src/vnode/src/vnodeVersion.c b/src/vnode/src/vnodeVersion.c
index 68fa32b2de94a6565d734a8adf95ed1e76d3c63c..d22bc17cbeda570f119a5a6e67637382f3a25bf8 100644
--- a/src/vnode/src/vnodeVersion.c
+++ b/src/vnode/src/vnodeVersion.c
@@ -90,7 +90,7 @@ int32_t vnodeSaveVersion(SVnodeObj *pVnode) {
   len += snprintf(content + len, maxLen - len, "}\n");
 
   fwrite(content, 1, len, fp);
-  fflush(fp);
+  fsync(fileno(fp));
   fclose(fp);
   free(content);
   terrno = 0;
diff --git a/tests/examples/JDBC/SpringJdbcTemplate/pom.xml b/tests/examples/JDBC/SpringJdbcTemplate/pom.xml
index 15aed1cf03b4e10e5a69e16be99ea2320a24609e..64a91b951bafe65e2f685fb57091221760fb99f9 100644
--- a/tests/examples/JDBC/SpringJdbcTemplate/pom.xml
+++ b/tests/examples/JDBC/SpringJdbcTemplate/pom.xml
@@ -47,7 +47,7 @@
         <dependency>
             <groupId>com.taosdata.jdbc</groupId>
             <artifactId>taos-jdbcdriver</artifactId>
-            <version>2.0.4</version>
+            <version>2.0.18</version>
         </dependency>
 
     </dependencies>
@@ -69,7 +69,7 @@
                 <configuration>
                     <archive>
                         <manifest>
-                            <mainClass>com.taosdata.jdbc.example.jdbcTemplate.App</mainClass>
+                            <mainClass>com.taosdata.example.jdbcTemplate.App</mainClass>
                         </manifest>
                     </archive>
                     <descriptorRefs>
diff --git a/tests/examples/JDBC/SpringJdbcTemplate/readme.md b/tests/examples/JDBC/SpringJdbcTemplate/readme.md
index 1fe8809b506c248f226edd0f3200c6e352c0a73b..b70a6565f88d0a08b8a26a60676e729ecdb39e2e 100644
--- a/tests/examples/JDBC/SpringJdbcTemplate/readme.md
+++ b/tests/examples/JDBC/SpringJdbcTemplate/readme.md
@@ -8,18 +8,16 @@
 修改 `src/main/resources/applicationContext.xml` 文件中 TDengine 的配置信息：
 
 ```xml
-
- <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
-        <property name="driverClassName" value="com.taosdata.jdbc.TSDBDriver"></property>
-        <property name="url" value="jdbc:TAOS://127.0.0.1:6030/log"></property>
-        <property name="username" value="root"></property>
-        <property name="password" value="taosdata"></property>
-    </bean>
-
-
-    <bean id = "jdbcTemplate"  class="org.springframework.jdbc.core.JdbcTemplate" >
-        <property name="dataSource" ref = "dataSource" ></property>
-    </bean>
+<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
+    <property name="driverClassName" value="com.taosdata.jdbc.TSDBDriver"></property>
+    <property name="url" value="jdbc:TAOS://127.0.0.1:6030/log"></property>
+    <property name="username" value="root"></property>
+    <property name="password" value="taosdata"></property>
+</bean>
+
+<bean id = "jdbcTemplate"  class="org.springframework.jdbc.core.JdbcTemplate" >
+    <property name="dataSource" ref = "dataSource" ></property>
+</bean>
 ```
 
 ### 打包运行
diff --git a/tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/jdbc/example/jdbcTemplate/App.java b/tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/example/jdbcTemplate/App.java
similarity index 86%
rename from tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/jdbc/example/jdbcTemplate/App.java
rename to tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/example/jdbcTemplate/App.java
index a03ca3924f9d86199c461a21d887b78e433ef6fe..6942d62a83adafb85496a81ce93866cd0d53611d 100644
--- a/tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/jdbc/example/jdbcTemplate/App.java
+++ b/tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/example/jdbcTemplate/App.java
@@ -1,9 +1,9 @@
-package com.taosdata.jdbc.example.jdbcTemplate;
+package com.taosdata.example.jdbcTemplate;
 
 
-import com.taosdata.jdbc.example.jdbcTemplate.dao.ExecuteAsStatement;
-import com.taosdata.jdbc.example.jdbcTemplate.dao.WeatherDao;
-import com.taosdata.jdbc.example.jdbcTemplate.domain.Weather;
+import com.taosdata.example.jdbcTemplate.dao.ExecuteAsStatement;
+import com.taosdata.example.jdbcTemplate.dao.WeatherDao;
+import com.taosdata.example.jdbcTemplate.domain.Weather;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.support.ClassPathXmlApplicationContext;
 
diff --git a/tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/jdbc/example/jdbcTemplate/dao/ExecuteAsStatement.java b/tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/example/jdbcTemplate/dao/ExecuteAsStatement.java
similarity index 58%
rename from tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/jdbc/example/jdbcTemplate/dao/ExecuteAsStatement.java
rename to tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/example/jdbcTemplate/dao/ExecuteAsStatement.java
index f146684cc01f75a211182a90e5cfee4058aea413..5947438e408b3b359b138bf989477f60fc327404 100644
--- a/tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/jdbc/example/jdbcTemplate/dao/ExecuteAsStatement.java
+++ b/tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/example/jdbcTemplate/dao/ExecuteAsStatement.java
@@ -1,4 +1,4 @@
-package com.taosdata.jdbc.example.jdbcTemplate.dao;
+package com.taosdata.example.jdbcTemplate.dao;
 
 public interface ExecuteAsStatement{
 
diff --git a/tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/jdbc/example/jdbcTemplate/dao/impl/ExecuteAsStatementImpl.java b/tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/example/jdbcTemplate/dao/ExecuteAsStatementImpl.java
similarity index 75%
rename from tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/jdbc/example/jdbcTemplate/dao/impl/ExecuteAsStatementImpl.java
rename to tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/example/jdbcTemplate/dao/ExecuteAsStatementImpl.java
index 2700e701cc42034975ff902ebe1da01f040b5a69..059e3dda15ea36bcaad4309a434a06f020d0301b 100644
--- a/tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/jdbc/example/jdbcTemplate/dao/impl/ExecuteAsStatementImpl.java
+++ b/tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/example/jdbcTemplate/dao/ExecuteAsStatementImpl.java
@@ -1,6 +1,5 @@
-package com.taosdata.jdbc.example.jdbcTemplate.dao.impl;
+package com.taosdata.example.jdbcTemplate.dao;
 
-import com.taosdata.jdbc.example.jdbcTemplate.dao.ExecuteAsStatement;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.jdbc.core.JdbcTemplate;
 import org.springframework.stereotype.Repository;
diff --git a/tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/jdbc/example/jdbcTemplate/dao/WeatherDao.java b/tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/example/jdbcTemplate/dao/WeatherDao.java
similarity index 65%
rename from tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/jdbc/example/jdbcTemplate/dao/WeatherDao.java
rename to tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/example/jdbcTemplate/dao/WeatherDao.java
index 28962ee1e6803898a0ec24e2231a62d91bcbf6d6..19a07597f8df869dada4e258c4951f67132107a0 100644
--- a/tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/jdbc/example/jdbcTemplate/dao/WeatherDao.java
+++ b/tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/example/jdbcTemplate/dao/WeatherDao.java
@@ -1,6 +1,6 @@
-package com.taosdata.jdbc.example.jdbcTemplate.dao;
+package com.taosdata.example.jdbcTemplate.dao;
 
-import com.taosdata.jdbc.example.jdbcTemplate.domain.Weather;
+import com.taosdata.example.jdbcTemplate.domain.Weather;
 
 import java.util.List;
 
diff --git a/tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/jdbc/example/jdbcTemplate/dao/impl/WeatherDaoImpl.java b/tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/example/jdbcTemplate/dao/WeatherDaoImpl.java
similarity index 84%
rename from tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/jdbc/example/jdbcTemplate/dao/impl/WeatherDaoImpl.java
rename to tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/example/jdbcTemplate/dao/WeatherDaoImpl.java
index 1e0e0ab68c63bdb87ad172f277fe2a65df79d229..8d4ca47d5ee5d351a48bcc1554531566116f5a52 100644
--- a/tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/jdbc/example/jdbcTemplate/dao/impl/WeatherDaoImpl.java
+++ b/tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/example/jdbcTemplate/dao/WeatherDaoImpl.java
@@ -1,20 +1,16 @@
-package com.taosdata.jdbc.example.jdbcTemplate.dao.impl;
+package com.taosdata.example.jdbcTemplate.dao;
 
-import com.taosdata.jdbc.example.jdbcTemplate.dao.WeatherDao;
-import com.taosdata.jdbc.example.jdbcTemplate.domain.Weather;
+import com.taosdata.example.jdbcTemplate.domain.Weather;
+import com.taosdata.example.jdbcTemplate.dao.WeatherDao;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.jdbc.core.BatchPreparedStatementSetter;
 import org.springframework.jdbc.core.JdbcTemplate;
-import org.springframework.jdbc.core.namedparam.SqlParameterSourceUtils;
-import org.springframework.jdbc.core.simple.SimpleJdbcInsert;
 import org.springframework.stereotype.Repository;
 
 import java.sql.PreparedStatement;
 import java.sql.SQLException;
 import java.sql.Timestamp;
-import java.util.HashMap;
 import java.util.List;
-import java.util.Map;
 
 @Repository
 public class WeatherDaoImpl implements WeatherDao {
diff --git a/tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/jdbc/example/jdbcTemplate/domain/Weather.java b/tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/example/jdbcTemplate/domain/Weather.java
similarity index 94%
rename from tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/jdbc/example/jdbcTemplate/domain/Weather.java
rename to tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/example/jdbcTemplate/domain/Weather.java
index 023b301481829b8d73a8af566d418aa8232ef899..1787a08c3554e017645fefbd35d7c4fd1bc60bd4 100644
--- a/tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/jdbc/example/jdbcTemplate/domain/Weather.java
+++ b/tests/examples/JDBC/SpringJdbcTemplate/src/main/java/com/taosdata/example/jdbcTemplate/domain/Weather.java
@@ -1,4 +1,4 @@
-package com.taosdata.jdbc.example.jdbcTemplate.domain;
+package com.taosdata.example.jdbcTemplate.domain;
 
 import java.sql.Timestamp;
 
diff --git a/tests/examples/JDBC/SpringJdbcTemplate/src/main/resources/applicationContext.xml b/tests/examples/JDBC/SpringJdbcTemplate/src/main/resources/applicationContext.xml
index 19ac433385fabe53548dcba25d5bb10965df17af..6d6cf6047e2545256ffd6f39e1e6160a965a6fa8 100644
--- a/tests/examples/JDBC/SpringJdbcTemplate/src/main/resources/applicationContext.xml
+++ b/tests/examples/JDBC/SpringJdbcTemplate/src/main/resources/applicationContext.xml
@@ -10,7 +10,7 @@
 
     <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
         <property name="driverClassName" value="com.taosdata.jdbc.TSDBDriver"></property>
-        <property name="url" value="jdbc:TAOS://192.168.236.137:6030/"></property>
+        <property name="url" value="jdbc:TAOS://127.0.0.1:6030/"></property>
         <property name="username" value="root"></property>
         <property name="password" value="taosdata"></property>
     </bean>
@@ -20,6 +20,6 @@
         <property name="dataSource" ref="dataSource"></property>
     </bean>
 
-    <context:component-scan base-package="com.taosdata.jdbc.example.jdbcTemplate"/>
+    <context:component-scan base-package="com.taosdata.example.jdbcTemplate"/>
 
 </beans>
diff --git a/tests/examples/JDBC/SpringJdbcTemplate/src/test/java/com/taosdata/jdbc/example/jdbcTemplate/BatcherInsertTest.java b/tests/examples/JDBC/SpringJdbcTemplate/src/test/java/com/taosdata/example/jdbcTemplate/BatcherInsertTest.java
similarity index 89%
rename from tests/examples/JDBC/SpringJdbcTemplate/src/test/java/com/taosdata/jdbc/example/jdbcTemplate/BatcherInsertTest.java
rename to tests/examples/JDBC/SpringJdbcTemplate/src/test/java/com/taosdata/example/jdbcTemplate/BatcherInsertTest.java
index 2f2446eb7049ae44ff3e142d62a2e51ab71b6f16..29d0f79fd4982d43078e590b4320c0df457ee44c 100644
--- a/tests/examples/JDBC/SpringJdbcTemplate/src/test/java/com/taosdata/jdbc/example/jdbcTemplate/BatcherInsertTest.java
+++ b/tests/examples/JDBC/SpringJdbcTemplate/src/test/java/com/taosdata/example/jdbcTemplate/BatcherInsertTest.java
@@ -1,9 +1,9 @@
-package com.taosdata.jdbc.example.jdbcTemplate;
+package com.taosdata.example.jdbcTemplate;
 
 
-import com.taosdata.jdbc.example.jdbcTemplate.dao.ExecuteAsStatement;
-import com.taosdata.jdbc.example.jdbcTemplate.dao.WeatherDao;
-import com.taosdata.jdbc.example.jdbcTemplate.domain.Weather;
+import com.taosdata.example.jdbcTemplate.dao.ExecuteAsStatement;
+import com.taosdata.example.jdbcTemplate.dao.WeatherDao;
+import com.taosdata.example.jdbcTemplate.domain.Weather;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
diff --git a/tests/examples/JDBC/SpringJdbcTemplate/src/test/java/com/taosdata/jdbc/AppTest.java b/tests/examples/JDBC/SpringJdbcTemplate/src/test/java/com/taosdata/jdbc/AppTest.java
deleted file mode 100644
index d0219f3db73d0c260420b642f997663acdd36f87..0000000000000000000000000000000000000000
--- a/tests/examples/JDBC/SpringJdbcTemplate/src/test/java/com/taosdata/jdbc/AppTest.java
+++ /dev/null
@@ -1,18 +0,0 @@
-package com.taosdata.jdbc;
-
-import static org.junit.Assert.assertTrue;
-
-import org.junit.Test;
-
-/**
- * Unit test for simple App.
- */
-public class AppTest {
-    /**
-     * Rigorous Test :-)
-     */
-    @Test
-    public void shouldAnswerWithTrue() {
-        assertTrue(true);
-    }
-}
diff --git a/tests/examples/JDBC/readme.md b/tests/examples/JDBC/readme.md
new file mode 100644
index 0000000000000000000000000000000000000000..9a017f4feab148cb7c3fd4132360c3075c6573cb
--- /dev/null
+++ b/tests/examples/JDBC/readme.md
@@ -0,0 +1,13 @@
+# TDengine examples
+
+| No.  |        Name        | Describe                                                     |
+| :--: | :----------------: | ------------------------------------------------------------ |
+|  1   |      JDBCDemo      | Example codes for JDBC-JNI, JDBC-RESTful, Subscribe          |
+|  2   |  connectionPools   | Example codes for HikariCP, Druid, dbcp, c3p0 connection pools |
+|  3   | SpringJdbcTemplate | Example codes for spring jdbcTemplate                        |
+|  4   |  mybatisplus-demo  | Example codes for mybatis                                    |
+|  5   |   springbootdemo   | Example codes for springboot                                 |
+|  6   |      taosdemo      | This is an internal tool for testing Our JDBC-JNI, JDBC-RESTful, RESTful interfaces |
+
+
+more detail: https://www.taosdata.com/cn//documentation20/connector-java/
\ No newline at end of file
diff --git a/tests/pytest/fulltest.sh b/tests/pytest/fulltest.sh
index 3be784ae95c84599c773d5c52b68ef5a630482ea..aee8f7502c354628d9cb0ca9df55ab4a7ad17c6f 100755
--- a/tests/pytest/fulltest.sh
+++ b/tests/pytest/fulltest.sh
@@ -20,6 +20,7 @@ python3 insert/retentionpolicy.py
 python3 ./test.py -f insert/alterTableAndInsert.py
 python3 ./test.py -f insert/insertIntoTwoTables.py
 #python3 ./test.py -f insert/before_1970.py
+python3 ./test.py -f insert/metadataUpdate.py
 python3 bug2265.py
 
 #table
diff --git a/tests/pytest/insert/metadataUpdate.py b/tests/pytest/insert/metadataUpdate.py
new file mode 100644
index 0000000000000000000000000000000000000000..c3ea5c6a7e7b5dbff9ded75394793e7fc4a7fd6c
--- /dev/null
+++ b/tests/pytest/insert/metadataUpdate.py
@@ -0,0 +1,67 @@
+###################################################################
+#           Copyright (c) 2016 by TAOS Technologies, Inc.
+#                     All rights reserved.
+#
+#  This file is proprietary and confidential to TAOS Technologies.
+#  No part of this file may be reproduced, stored, transmitted,
+#  disclosed or used in any form or by any means other than as
+#  expressly provided by the written permission from Jianhui Tao
+#
+###################################################################
+
+# -*- coding: utf-8 -*-
+
+import sys
+import taos
+from util.log import tdLog
+from util.cases import tdCases
+from util.sql import tdSql
+from util.dnodes import tdDnodes
+from multiprocessing import  Process
+
+class TDTestCase:
+    def init(self, conn, logSql):
+        tdLog.debug("start to execute %s" % __file__)
+        tdSql.init(conn.cursor(), logSql)
+
+        self.ts = 1538548685000
+
+    def updateMetadata(self):
+        self.host = "127.0.0.1"
+        self.user = "root"
+        self.password = "taosdata"
+        self.config = tdDnodes.getSimCfgPath()
+
+        self.conn = taos.connect(host = self.host, user = self.user, password = self.password, config = self.config)
+        self.cursor = self.conn.cursor()    
+        self.cursor.execute("alter table db.tb add column col2 int")
+        print("alter table done")
+
+    def run(self):
+        tdSql.prepare()
+
+        print("==============step1")
+        tdSql.execute("create table if not exists tb (ts timestamp, col1 int)")
+        tdSql.execute("insert into tb values(%d, 1)" % self.ts)
+
+        print("==============step2")
+        tdSql.query("select * from tb")
+        tdSql.checkRows(1)
+
+        p = Process(target=self.updateMetadata, args=())
+        p.start()        
+        p.join()
+        p.terminate()
+        
+        tdSql.execute("insert into tb values(%d, 1, 2)" % (self.ts + 1))
+
+        print("==============step2")
+        tdSql.query("select * from tb")
+        tdSql.checkRows(2)
+
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())
diff --git a/tests/script/general/parser/dbtbnameValidate.sim b/tests/script/general/parser/dbtbnameValidate.sim
index 072fd740d4d2960891c774a4e24a999c477ebc96..48c5d4a1f94337a6324826d78eda3ad498ac3d76 100644
--- a/tests/script/general/parser/dbtbnameValidate.sim
+++ b/tests/script/general/parser/dbtbnameValidate.sim
@@ -26,11 +26,11 @@ sql use ' XYZ '
 
 sql drop database 'abc123'
 sql drop database '_ab1234'
-sql drop database 'ABC123'
+sql_error drop database 'ABC123'
 sql drop database '_ABC123'
 sql drop database 'aABb123'
 sql drop database ' xyz '
-sql drop database ' XYZ '
+sql_error drop database ' XYZ '
 
 
 sql use abc
@@ -67,9 +67,9 @@ sql describe mt
 sql describe sub_001
 sql describe sub_dy_tbl
 
-sql_error describe Dd
-sql_error describe FF
-sql_error describe gG
+sql describe Dd
+sql describe FF
+sql describe gG
 
 sql drop table abc.cc
 sql drop table  'abc.Dd'
@@ -119,4 +119,4 @@ if $rows != 4 then
   return -1
 endi
 
-system sh/exec.sh -n dnode1 -s stop -x SIGINT
\ No newline at end of file
+system sh/exec.sh -n dnode1 -s stop -x SIGINT