fix: wait_timeout update for the best practices (#16453)

best-practices/java-app-best-practices.md

@@ -223,7 +223,12 @@ The application needs to return the connection after finishing using it. It is a
 
 ### Probe configuration
 
-The connection pool maintains persistent connections to TiDB. TiDB does not proactively close client connections by default (unless an error is reported), but generally there will be network proxies such as LVS or HAProxy between the client and TiDB. Usually, these proxies will proactively clean up connections that are idle for a certain period of time (controlled by the proxy's idle configuration). In addition to paying attention to the idle configuration of the proxies, the connection pool also needs to keep alive or probe connections.
+The connection pool maintains persistent connections from clients to TiDB as follows:
+
+- Before v5.4, TiDB does not proactively close client connections by default (unless an error is reported).
+- Starting from v5.4, TiDB automatically closes client connections after `28800` seconds (this is, `8` hours) of inactivity by default. You can control this timeout setting using the TiDB and MySQL compatible `wait_timeout` variable. For more information, see [JDBC Query Timeout](/develop/dev-guide-timeouts-in-tidb.md#jdbc-query-timeout).
+
+Moreover, there might be network proxies such as [LVS](https://en.wikipedia.org/wiki/Linux_Virtual_Server) or [HAProxy](https://en.wikipedia.org/wiki/HAProxy) between clients and TiDB. These proxies typically proactively clean up connections after a specific idle period (determined by the proxy's idle configuration). In addition to monitoring the proxy's idle configuration, connection pools also need to maintain or probe connections for keep-alive.
 
 If you often see the following error in your Java application:
 

develop/dev-guide-connection-parameters.md

@@ -36,7 +36,12 @@ The application needs to return the connection after finishing using it. It is r
 
 ### Probe configuration
 
-The connection pool maintains persistent connections to TiDB. TiDB does not proactively close client connections by default (unless an error is reported), but generally, there are also network proxies such as [LVS](https://en.wikipedia.org/wiki/Linux_Virtual_Server) or [HAProxy](https://en.wikipedia.org/wiki/HAProxy) between the client and TiDB. Usually, these proxies proactively clean up connections that are idle for a certain period. In addition to paying attention to the idle configuration of the proxies, the connection pool also needs to keep alive or probe connections.
+The connection pool maintains persistent connections from clients to TiDB as follows:
+
+- Before v5.4, TiDB does not proactively close client connections by default (unless an error is reported).
+- Starting from v5.4, TiDB automatically closes client connections after `28800` seconds (this is, `8` hours) of inactivity by default. You can control this timeout setting using the TiDB and MySQL compatible `wait_timeout` variable. For more information, see [JDBC Query Timeout](/develop/dev-guide-timeouts-in-tidb.md#jdbc-query-timeout).
+
+Moreover, there might be network proxies such as [LVS](https://en.wikipedia.org/wiki/Linux_Virtual_Server) or [HAProxy](https://en.wikipedia.org/wiki/HAProxy) between clients and TiDB. These proxies typically proactively clean up connections after a specific idle period (determined by the proxy's idle configuration). In addition to monitoring the proxy's idle configuration, connection pools also need to maintain or probe connections for keep-alive.
 
 If you often see the following error in your Java application: