make net_thread_count adaptive

src/observer/ob_srv_network_frame.cpp

@@ -56,7 +56,11 @@ int ObSrvNetworkFrame::init()
   const char* mysql_unix_path = "unix:run/mysql.sock";
   const uint32_t rpc_port = static_cast<uint32_t>(GCONF.rpc_port);
   ObNetOptions opts;
-  const int io_cnt = static_cast<int>(GCONF.net_thread_count);
+  int io_cnt = static_cast<int>(GCONF.net_thread_count);
+  // make net thread count adaptive
+  if (0 == io_cnt) {
+    io_cnt = max(6, get_cpu_num() / 8);
+  }
   const int hp_io_cnt = static_cast<int>(GCONF.high_priority_net_thread_count);
   const bool use_easy_ma = hp_io_cnt > 0;
   opts.rpc_io_cnt_ = io_cnt;

src/share/parameter/ob_parameter_seed.ipp

@@ -59,8 +59,8 @@ DEF_TIME(internal_sql_execute_timeout, OB_CLUSTER_PARAMETER, "30s", "[1000us, 10
     "the number of microseconds an internal DML request is permitted to "
     "execute before it is terminated. Range: [1000us, 10m]",
     ObParameterAttr(Section::OBSERVER, Source::DEFAULT, EditLevel::DYNAMIC_EFFECTIVE));
-DEF_INT(net_thread_count, OB_CLUSTER_PARAMETER, "12", "[1,100]",
-    "the number of rpc/mysql I/O threads for Libeasy. Range: [1, 100] in integer",
+DEF_INT(net_thread_count, OB_CLUSTER_PARAMETER, "0", "[0,128]",
+    "the number of rpc/mysql I/O threads for Libeasy. Range: [0, 128] in integer, 0 stands for max(6, CPU_NUM/8)",
     ObParameterAttr(Section::OBSERVER, Source::DEFAULT, EditLevel::STATIC_EFFECTIVE));
 DEF_INT(high_priority_net_thread_count, OB_CLUSTER_PARAMETER, "0", "[0,100]",
     "the number of rpc I/O threads for high priority messages, 0 means set off. Range: [0, 100] in integer",