B4J Question update mysql-connector ?

[marcick]

In JRDC2 is declared #AdditionalJar: mysql-connector-java-5.1.37-bin

but I see it is available a new version mysql-connector-java-8.0.18

Does it make sense to update it ?
My JRDC2 server app sometimes (after many days or weeks) crash with strange errors like this and I was wondering if updating the mysql-connector could help

2019-12-12 17:11:49 - RDCHandler_Handle error, method query2, (TimeoutException) com.mchange.v2.resourcepool.TimeoutException: A client timed out while waiting to acquire a resource from com.mchange.v2.resourcepool.BasicResourcePool@6615435c -- timeout at awaitAvailable()
2019-12-12 17:11:50 App Error 2: (SQLException) java.sql.SQLException: An attempt by a client to checkout a Connection has timed out.
(SQLException) java.sql.SQLException: An attempt by a client to checkout a Connection has timed out.
java.sql.SQLException: An attempt by a client to checkout a Connection has timed out.
    at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.java:118)
    at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.java:77)
    at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:690)
    at com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.getConnection(AbstractPoolBackedDataSource.java:140)
    at anywheresoftware.b4j.object.ConnectionPool.GetConnection(ConnectionPool.java:45)
    at jrdc.bmap4aw.rdcconnector._vvvvvvvvvvvvvvvvvv5(rdcconnector.java:71)

 

[OliverA]

Could be that 1) pool size is too small or 2) connections are kept open by MySQL (or something else). For the first two issues see the following thread for solutions: https://www.b4x.com/android/forum/t...ns-with-connectionpool-library.42647/#content

 

[marcick]

Hi OliverA. This is an old recurring issue. I'm sure there is something of wrong in my code but I still have to understand.
Difficult to follow those suggestion ... for now I just wanted to know if does it make sense to update the mysql-connector.

Also would be interesting to know if there is a B4j code that can monitor the number of opened connection, so when I capture the crash I print it and see if the problem is this or not.

 

[Jorge M A]

Does it make sense to update it ?

That will depend on which version of MySql you have installed on your server and how you are using it.

You can read the Release Notes for each.

https://dev.mysql.com/doc/relnotes/connector-j/5.1/en/
https://dev.mysql.com/doc/relnotes/connector-j/8.0/en/

 

[marcick]

Thanks.
MySql version is 5.7
I will use mysql-connector-java-8.0.18 instead of the original mysql-connector-java-5.1.37