change flush vm times to 11 and add log

server/src/assembly/resources/conf/iotdb-engine.properties

@@ -262,7 +262,7 @@ max_vm_num=5
 merge_chunk_point_number=10000
 
 # When vmfiles merge times exceeds this, merge the vmfile to the tsfile.
-max_merge_chunk_num_in_tsfile=9
+max_merge_chunk_num_in_tsfile=11
 
 # How many thread will be set up to perform merge main tasks, 1 by default.
 # Set to 1 when less than or equal to 0.

server/src/main/java/org/apache/iotdb/db/conf/IoTDBConfig.java

@@ -236,12 +236,12 @@ public class IoTDBConfig {
   /**
    * When a TsFile's file size (in byte) exceed this, the TsFile is forced closed.
    */
-  private long tsFileSizeThreshold = 512 * 1024 * 1024L;
+  private long tsFileSizeThreshold = 128 * 1024 * 1024L;
 
   /**
    * When a memTable's size (in byte) exceeds this, the memtable is flushed to disk.
    */
-  private long memtableSizeThreshold = 128 * 1024 * 1024L;
+  private long memtableSizeThreshold = 64 * 1024 * 1024L;
 
   /**
    * When average series point number reaches this, flush the memtable to disk
@@ -256,7 +256,7 @@ public class IoTDBConfig {
   /**
    * When vmfiles merge times exceeds this, merge the vmfile to the tsfile.
    */
-  private int maxMergeChunkNumInTsFile = 5;
+  private int maxMergeChunkNumInTsFile = 11;
 
   /**
    * whether to cache meta data(ChunkMetaData and TsFileMetaData) or not.

server/src/main/java/org/apache/iotdb/db/engine/storagegroup/TsFileProcessor.java

@@ -702,6 +702,7 @@ public class TsFileProcessor {
           if ((vmPointNum + memTableToFlush.getTotalPointsNum()) / pathMeasurementSchemaMap.size()
               > config.getMergeChunkPointNumberThreshold() 
               || flushVmTimes >= config.getMaxMergeChunkNumInTsFile()) {
+            logger.info("[Flush] merge {} vms to TsFile", vmTsFileResources.size() + 1);
             isVm = false;
             isFull = false;
             flushVmTimes = 0;
@@ -712,6 +713,7 @@ public class TsFileProcessor {
           } else {
             // merge vm files
             if (config.getMaxVmNum() <= vmTsFileResources.size()) {
+              logger.info("[Flush] merge {} vms to vm", vmTsFileResources.size() + 1);
               isVm = true;
               isFull = true;
               flushTask = new MemTableFlushTask(memTableToFlush, writer, vmTsFileResources,
@@ -719,6 +721,7 @@ public class TsFileProcessor {
                   sequence,
                   storageGroupName);
             } else {
+              logger.info("[Flush] flush a vm");
               isVm = true;
               isFull = false;
               File newVmFile = createNewVMFile(tsFileResource);