I don’t have exact reproduction steps yet (otherwise I would have filed an
issue), but on Artemis 2.22 using a mysql backed journal our QA can reliably
send messages that crash the server:
```
2022-09-15 10:42:24,843 WARN [org.apache.activemq.artemis.journal] AMQ142021:
Error on IO callback, class com.sun.proxy.$Proxy21 cannot be cast to class
com.mysql.cj.jdbc.ClientPreparedStatement (com.sun.proxy.$Proxy21 and
com.mysql.cj.jdbc.ClientPreparedStatement are in unnamed module of loader
java.net.URLClassLoader @3a5ed7a6)
2022-09-15 10:42:24,845 ERROR [org.apache.activemq.artemis.core.server]
AMQ222010: Critical IO Error, shutting down the server.
file=org.apache.activemq.artemis.jdbc.store.file.JDBCSequentialFile@3452c05f,
message=Error writing to JDBC file.: java.lang.ClassCastException: class
com.sun.proxy.$Proxy21 cannot be cast to class
com.mysql.cj.jdbc.ClientPreparedStatement (com.sun.proxy.$Proxy21 and
com.mysql.cj.jdbc.ClientPreparedStatement are in unnamed module of loader
java.net.URLClassLoader @3a5ed7a6)
at
com.mysql.cj.jdbc.result.UpdatableResultSet.syncUpdate(UpdatableResultSet.java:1143)
[mysql-connector-java-8.0.28.jar:8.0.28]
at
com.mysql.cj.jdbc.result.UpdatableResultSet.updateBlob(UpdatableResultSet.java:1283)
[mysql-connector-java-8.0.28.jar:8.0.28]
at
java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[java.base:]
at
java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
[java.base:]
at
java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
[java.base:]
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
[java.base:]
at
com.mysql.cj.jdbc.ha.MultiHostConnectionProxy$JdbcInterfaceProxy.invoke(MultiHostConnectionProxy.java:107)
[mysql-connector-java-8.0.28.jar:8.0.28]
at com.sun.proxy.$Proxy22.updateBlob(Unknown Source)
at
org.apache.commons.dbcp2.DelegatingResultSet.updateBlob(DelegatingResultSet.java:1411)
[commons-dbcp2-2.7.0.jar:2.7.0]
at
org.apache.commons.dbcp2.DelegatingResultSet.updateBlob(DelegatingResultSet.java:1411)
[commons-dbcp2-2.7.0.jar:2.7.0]
at
org.apache.commons.dbcp2.DelegatingResultSet.updateBlob(DelegatingResultSet.java:1411)
[commons-dbcp2-2.7.0.jar:2.7.0]
at
org.apache.activemq.artemis.jdbc.store.file.JDBCSequentialFileFactoryDriver.writeToFile(JDBCSequentialFileFactoryDriver.java:284)
[artemis-jdbc-store-2.22.0.jar:2.22.0]
at
org.apache.activemq.artemis.jdbc.store.file.JDBCSequentialFile.internalWrite(JDBCSequentialFile.java:167)
[artemis-jdbc-store-2.22.0.jar:2.22.0]
at
org.apache.activemq.artemis.jdbc.store.file.JDBCSequentialFile.internalWrite(JDBCSequentialFile.java:203)
[artemis-jdbc-store-2.22.0.jar:2.22.0]
at
org.apache.activemq.artemis.jdbc.store.file.JDBCSequentialFile.lambda$scheduleWrite$1(JDBCSequentialFile.java:214)
[artemis-jdbc-store-2.22.0.jar:2.22.0]
at
org.apache.activemq.artemis.utils.actors.OrderedExecutor.doTask(OrderedExecutor.java:42)
[artemis-commons-2.22.0.jar:]
at
org.apache.activemq.artemis.utils.actors.OrderedExecutor.doTask(OrderedExecutor.java:31)
[artemis-commons-2.22.0.jar:]
at
org.apache.activemq.artemis.utils.actors.ProcessorBase.executePendingTasks(ProcessorBase.java:65)
[artemis-commons-2.22.0.jar:]
at
java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
[java.base:]
at
java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
[java.base:]
at
org.apache.activemq.artemis.utils.ActiveMQThreadFactory$1.run(ActiveMQThreadFactory.java:118)
[artemis-commons-2.22.0.jar:]
2022-09-15 10:42:24,848 WARN [org.apache.activemq.artemis.journal] AMQ142021:
Error on IO callback, Error writing to JDBC file.
2022-09-15 10:42:24,854 WARN [org.apache.activemq.artemis.core.client]
AMQ212004: Failed to connect to server.
2022-09-15 10:42:24,909 WARN [org.apache.activemq.artemis.journal] AMQ142021:
Error on IO callback, class com.sun.proxy.$Proxy21 cannot be cast to class
com.mysql.cj.jdbc.ClientPreparedStatement (com.sun.proxy.$Proxy21 and
com.mysql.cj.jdbc.ClientPreparedStatement are in unnamed module of loader
java.net.URLClassLoader @3a5ed7a6)
2022-09-15 10:42:24,926 WARN [org.apache.activemq.artemis.journal] AMQ142021:
Error on IO callback, Error writing to JDBC file.
```
As you can see, whatever the original problem was it is hidden by the
ClassCastException in Artemis.
When I learn more I will file an issue (unless the problem has been resolved in
a later version) and hopefully a fix.
Stephen E. Baker
