Unexpected packet type: 52 thrown in Postgres - QueryExecutorImpl.processResults - postgresql

Question

I am trying to save an entity to the Postgres DB from an application running in AWS. But at some point of time the application is getting crashed by throwing below error repeatedly.
With the below error logs it seems to be an issue with Java IO communication.
But I am not sure why this issue is occurring, when calling this particular save operation as other DB calls are working fine.
Unexpected packet type: 52 at
org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:2333)
Logs:
org.springframework.transaction.TransactionSystemException: Could not roll back JPA transaction; nested exception is org.hibernate.TransactionException: Unable to rollback against JDBC Connection at org.springframework.orm.jpa.JpaTransactionManager.doRollback(JpaTransactionManager.java:563) at
org.springframework.transaction.support.AbstractPlatformTransactionManager.processRollback(AbstractPlatformTransactionManager.java:838) at
org.springframework.transaction.support.AbstractPlatformTransactionManager.rollback(AbstractPlatformTransactionManager.java:812) at
org.springframework.transaction.interceptor.TransactionAspectSupport.completeTransactionAfterThrowing(TransactionAspectSupport.java:551) at
org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:298) at
org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:98) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) at
org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:688) at
com.xxxx.xxxxxx.xxxxx.prepare.PrepareService$$EnhancerBySpringCGLIB$$b0df57d1.save(<generated>) at
com.xxxx.xxxxxxx`.xxxxxx.scheduler.job.PendingJob.execute(PendingJob.java:111) at sun.reflect.GeneratedMethodAccessor178.invoke(Unknown Source) at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at
java.lang.reflect.Method.invoke(Method.java:498) at
org.springframework.scheduling.support.ScheduledMethodRunnable.run(ScheduledMethodRunnable.java:84) at
net.javacrumbs.shedlock.core.DefaultLockingTaskExecutor.executeWithLock(DefaultLockingTaskExecutor.java:54) at
net.javacrumbs.shedlock.core.DefaultLockingTaskExecutor.executeWithLock(DefaultLockingTaskExecutor.java:39) at net.javacrumbs.shedlock.core.DefaultLockManager.executeWithLock(DefaultLockManager.java:51) at
net.javacrumbs.shedlock.core.LockableRunnable.run(LockableRunnable.java:35) at
org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:54) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308) at
java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180) at
java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:748)
Caused by: org.hibernate.TransactionException: Unable to rollback against JDBC Connection at
org.hibernate.resource.jdbc.internal.AbstractLogicalConnectionImplementor.rollback(AbstractLogicalConnectionImplementor.java:122) at
org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl$TransactionDriverControlImpl.rollback(JdbcResourceLocalTransactionCoordinatorImpl.java:294) at
org.hibernate.engine.transaction.internal.TransactionImpl.rollback(TransactionImpl.java:139) at org.springframework.orm.jpa.JpaTransactionManager.doRollback(JpaTransactionManager.java:559) ... 25
common frames omitted
Caused by: org.postgresql.util.PSQLException: An I/O error occurred while sending to the backend. at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:335) at
org.postgresql.jdbc.PgConnection.executeTransactionCommand(PgConnection.java:755) at
org.postgresql.jdbc.PgConnection.rollback(PgConnection.java:799) at
com.zaxxer.hikari.pool.ProxyConnection.rollback(ProxyConnection.java:370) at
com.zaxxer.hikari.pool.HikariProxyConnection.rollback(HikariProxyConnection.java) at
org.hibernate.resource.jdbc.internal.AbstractLogicalConnectionImplementor.rollback(AbstractLogicalConnectionImplementor.java:116) 28 common frames omitted
Caused by: java.io.IOException:
Unexpected packet type: 52 at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:2333) at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:308) ... 33 common frames
So kindly let me know any leads to solve this issue :)
Thanks in advance,
Satheesh

Answer 1

The server sent a message with the first byte equal to '4', which does not correspond to a valid message type. Ask those folks at Amazon.