Troubleshooting Siddhi Runtime Exceptions and Errors

The possible exceptions that may occur relating to Siddhi runtime are as follows:

NotSerializableException

Sample Error Log	TID: [-1] [] [2017-04-18 17:02:19,876] ERROR {org.wso2.siddhi.core.util.snapshot.ByteSerializer} - Error when writing byte array. org.wso2.carbon.event.receiver.core.internal.management.BlockingEventQueue {org.wso2.siddhi.core.util.snapshot.ByteSerializer} java.io.NotSerializableException: org.wso2.carbon.event.receiver.core.internal.management.BlockingEventQueue
Occurrence	This occurs when non-serializable objects are passed through the `getState()` method. This mostly occurs in custom components and sometimes in default components.
Possible reasons	This is incorrect behaviour caused by developer error.
Troubleshooting options	Read the error log and identify the class and the object that are not serializable.
Recommended action	The relevant object must be patched to implement a serializable interface. You can patch and fix the issue, or report a Github issue in the product repository so that the product team can fix it.

Dropping event chunk - NullpointerException

Sample Error Log

TID: [-1] [] [2017-04-18 17:02:19,876] ERROR {org.wso2.siddhi.core.util.snapshot.ByteSerializer} -  Error when writing byte array. org.wso2.carbon.event.receiver.core.internal.management.BlockingEventQueue {org.wso2.siddhi.core.util.snapshot.ByteSerializer}
java.io.NotSerializableException: org.wso2.carbon.event.receiver.core.internal.management.BlockingEventQueue

Recommended action This is a known issue. To fix this, apply the WSO2-CARBON-PATCH-4.4.0-1028 patch.