# MySQL Source creation fails

**URL:** <https://community.dremio.com/t/mysql-source-creation-fails/6738>\
**Category:** Uncategorized\
**Created:** [December 14, 2020, 4:37pm UTC](https://community.dremio.com/t/mysql-source-creation-fails/6738 "2020-12-14T16:37:38Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![udaykrishna5](https://avatars.discourse-cdn.com/v4/letter/u/c0e974/32.png) [@udaykrishna5](https://community.dremio.com/u/udaykrishna5)\
**Post date:** [December 14, 2020, 4:37pm UTC](https://community.dremio.com/t/mysql-source-creation-fails/6738/1 "2020-12-14T16:37:38Z")

</div>

New MySQL source creation fails with the following error

```auto
2020-12-14 15:20:08,457 [start-mysqlsource] ERROR c.d.e.s.jdbc.JdbcSchemaFetcherImpl - Connection is not valid.
java.sql.SQLNonTransientConnectionException: could not load system variables
        at org.mariadb.jdbc.internal.util.exceptions.ExceptionMapper.get(ExceptionMapper.java:234)
        at org.mariadb.jdbc.internal.util.exceptions.ExceptionMapper.getException(ExceptionMapper.java:165)
        at org.mariadb.jdbc.MariaDbDataSource.getConnection(MariaDbDataSource.java:290)
        at org.mariadb.jdbc.MariaDbDataSource.getPooledConnection(MariaDbDataSource.java:455)
        at org.apache.commons.dbcp2.datasources.InstanceKeyDataSource.testCPDS(InstanceKeyDataSource.java:1018)
        at org.apache.commons.dbcp2.datasources.SharedPoolDataSource.registerPool(SharedPoolDataSource.java:167)
        at org.apache.commons.dbcp2.datasources.SharedPoolDataSource.getPooledConnectionAndInfo(SharedPoolDataSource.java:127)
        at org.apache.commons.dbcp2.datasources.InstanceKeyDataSource.getConnection(InstanceKeyDataSource.java:884)
        at org.apache.commons.dbcp2.datasources.InstanceKeyDataSource.getConnection(InstanceKeyDataSource.java:858)
        at com.dremio.exec.store.jdbc.CloseableDataSource$DatasourceWrapper.getConnection(CloseableDataSource.java:87)
        at com.dremio.exec.store.jdbc.JdbcSchemaFetcherImpl.getState(JdbcSchemaFetcherImpl.java:654)
        at com.dremio.exec.store.jdbc.JdbcStoragePlugin.getState(JdbcStoragePlugin.java:423)
        at com.dremio.exec.catalog.ManagedStoragePlugin.setLocals(ManagedStoragePlugin.java:827)
        at com.dremio.exec.catalog.ManagedStoragePlugin.lambda$newStartSupplier$1(ManagedStoragePlugin.java:524)
        at com.dremio.exec.catalog.ManagedStoragePlugin.lambda$nameSupplier$3(ManagedStoragePlugin.java:591)
        at java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1604)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
        at java.lang.Thread.run(Thread.java:748)
Caused by: java.sql.SQLNonTransientConnectionException: could not load system variables
        at org.mariadb.jdbc.internal.util.exceptions.ExceptionMapper.get(ExceptionMapper.java:234)
        at org.mariadb.jdbc.internal.util.exceptions.ExceptionMapper.getException(ExceptionMapper.java:165)
        at org.mariadb.jdbc.internal.protocol.AbstractConnectProtocol.connectWithoutProxy(AbstractConnectProtocol.java:1199)
        at org.mariadb.jdbc.internal.util.Utils.retrieveProxy(Utils.java:560)
        at org.mariadb.jdbc.MariaDbConnection.newConnection(MariaDbConnection.java:174)
        at org.mariadb.jdbc.MariaDbDataSource.getConnection(MariaDbDataSource.java:288)
        ... 16 common frames omitted
Caused by: java.sql.SQLNonTransientConnectionException: could not load system variables
        at org.mariadb.jdbc.internal.util.exceptions.ExceptionMapper.get(ExceptionMapper.java:234)
        at org.mariadb.jdbc.internal.util.exceptions.ExceptionMapper.connException(ExceptionMapper.java:95)
        at org.mariadb.jdbc.internal.protocol.AbstractConnectProtocol.requestSessionDataWithShow(AbstractConnectProtocol.java:723)
        at org.mariadb.jdbc.internal.protocol.AbstractConnectProtocol.readPipelineAdditionalData(AbstractConnectProtocol.java:687)
        at org.mariadb.jdbc.internal.protocol.AbstractConnectProtocol.connect(AbstractConnectProtocol.java:535)
        at org.mariadb.jdbc.internal.protocol.AbstractConnectProtocol.connectWithoutProxy(AbstractConnectProtocol.java:1195)
        ... 19 common frames omitted
Caused by: java.sql.SQLException: Connection is closed
        at org.mariadb.jdbc.internal.protocol.AbstractQueryProtocol.cmdPrologue(AbstractQueryProtocol.java:1801)
        at org.mariadb.jdbc.internal.protocol.AbstractQueryProtocol.executeQuery(AbstractQueryProtocol.java:212)
        at org.mariadb.jdbc.internal.protocol.AbstractConnectProtocol.requestSessionDataWithShow(AbstractConnectProtocol.java:700)
        ... 22 common frames omitted
2020-12-14 15:20:08,457 [start-mysqlsource] WARN c.d.e.catalog.ManagedStoragePlugin - Error starting new source: mysqlsource
java.lang.Exception: Unavailable:
        at com.dremio.exec.catalog.ManagedStoragePlugin.lambda$newStartSupplier$1(ManagedStoragePlugin.java:529)
        at com.dremio.exec.catalog.ManagedStoragePlugin.lambda$nameSupplier$3(ManagedStoragePlugin.java:591)
        at java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1604)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
        at java.lang.Thread.run(Thread.java:748)
2020-12-14 15:20:08,457 [start-mysqlsource] INFO c.d.s.s.LocalSchedulerService - Cancelling task metadata-refresh-wakeup-mysqlsource

```

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<div class="post-metadata">

**Author:** ![balaji.ramaswamy](https://sea2.discourse-cdn.com/flex020/user_avatar/community.dremio.com/balaji.ramaswamy/32/843_2.png) [@balaji.ramaswamy](https://community.dremio.com/u/balaji.ramaswamy)\
**Post date:** [December 15, 2020, 7:00am UTC](https://community.dremio.com/t/mysql-source-creation-fails/6738/2 "2020-12-15T07:00:50Z")

</div>

@udaykrishna5

What version of Mysql is this?

> **[\[CONJ-714\] Error reading SessionVariables is thrown when falling back to...](https://jira.mariadb.org/browse/CONJ-714)**

  

> <https://github.com/sysown/proxysql/issues/2523>
>
> This is a reocuring bug showing the same behaviour as reported in issue #2009.
> We are using MariaDB Connector/J 2.4.3 and ProxySQL...

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<div class="post-metadata">

**Author:** ![udaykrishna5](https://avatars.discourse-cdn.com/v4/letter/u/c0e974/32.png) [@udaykrishna5](https://community.dremio.com/u/udaykrishna5)\
**Post date:** [December 15, 2020, 8:35am UTC](https://community.dremio.com/t/mysql-source-creation-fails/6738/3 "2020-12-15T08:35:07Z")

</div>

@balaji.ramaswamy 5.7.12

---

<div class="post-metadata">

**Author:** ![balaji.ramaswamy](https://sea2.discourse-cdn.com/flex020/user_avatar/community.dremio.com/balaji.ramaswamy/32/843_2.png) [@balaji.ramaswamy](https://community.dremio.com/u/balaji.ramaswamy)\
**Post date:** [December 16, 2020, 8:16am UTC](https://community.dremio.com/t/mysql-source-creation-fails/6738/4 "2020-12-16T08:16:48Z")

</div>

@udaykrishna5

That version seems to be totally fine. Let me further look into this and get back to you. Did you get a chance to look into those forums?