#2403 MySQL max_idle_time is 10 by default (#2405)

* #2403 MySQL max_idle_time is 10 by default
Signed-off-by: Njinhai <hai.jin@zilliz.com>

* #2403 MySQL max_idle_time is 10 by default
Signed-off-by: Njinhai <hai.jin@zilliz.com>

CHANGELOG.md

@@ -18,14 +18,15 @@ Please mark all change in change log and use the issue from GitHub
 ## Bug
 -   \#2378 Duplicate data after server restart
 -   \#2399 The nlist set by the user may not take effect
+-   \#2403 MySQL max_idle_time is 10 by default
 
 ## Feature
 -   \#2363 Update branch version
--   \#2381 Upgrade to faiss_1.6.3
 
 ## Improvement
 -   \#2307 Disable index SPTAG by default
 -   \#2370 Clean compile warning
+-   \#2381 Upgrade FAISS to 1.6.3
 
 ## Task
 

core/src/db/meta/MySQLConnectionPool.h

@@ -73,7 +73,7 @@ class MySQLConnectionPool : public mysqlpp::ConnectionPool {
 
     int max_pool_size_;
 
-    unsigned int max_idle_time_ = 0;  // 10 seconds
+    unsigned int max_idle_time_ = 10;  // 10 seconds
 };
 
 }  // namespace meta