com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionE xception: Communications link failure during commit(). Transaction resolution unknown

[Prashanth Y R]

I have a WildFly application running on an AWS EC2 instance which is connected to MySQL database and is installed on another EC2 instance in the same VPC and subnet. The connectivity between these instances is perfectly made and the application is working fine with a proper connection to the database instance.

However, upon a specific API execution, we see the below expectation in the server log which eventually leads to the failure of execution. I'm unsure what is the problem as the application is running fine and was even fine with the specific API. We have started seeing this expectation only in the last few days. The connectivity between these two instances is perfectly made without any issues.

Help me with the direction in which I need to start the debugging. We haven't made any changes to database properties lately.

Exception:

2024-01-03 09:37:29,211 WARN [org.jboss.jca.core.connectionmanager.listener.TxConnectionListener] (default task-4350) IJ000305: Connection error occured: org.jboss.jca.core.connectionmanager.listener.TxConnectionListener@64e864b[state=NORMAL managed connection=org.jboss.jca.adapters.jdbc.local.LocalManagedConnection@5fed54bf connection handles=1 lastReturned=1704254772312 lastValidated=1704253893776 lastCheckedOut=1704254772349 trackByTx=true pool=org.jboss.jca.core.connectionmanager.pool.strategy.OnePool@1433812f mcp=SemaphoreConcurrentLinkedQueueManagedConnectionPool@98d4f08[pool=wooqDataSource] xaResource=LocalXAResourceImpl@19fdf2dc[connectionListener=64e864b connectionManager=3faa0fba warned=false currentXid=null productName=MySQL productVersion=5.7.30-log jndiName=java:jboss/datasources/WooqerDS] txSync=TransactionSynchronization@1451402909{tx=Local transaction (delegate=TransactionImple < ac, BasicAction: 0:ffff0a400c15:77ad8b58:6592d3a3:1bcf42e status: ActionStatus.COMMITTING >, owner=Local transaction context for provider JBoss JTA transaction provider) wasTrackByTx=true enlisted=true cancel=false}]: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Communications link failure during commit(). Transaction resolution unknown.