Frequently Exceptions

This article describes common exception scenarios and exception information in MDB systems, and how to resolve them.

The Exception Scenario

Data capture service state exception

• Cause: Click view anomaly information, or view <./kafka/logs/connectDistributed.out> anomaly information in log files.
• Solution: Rectify the fault according to the fault information. If the fault persists, contact technical support.。
• Recover: After the exception is rectified, operation synchronization starts to restore data synchronization. If an exception occurs, data needs to be synchronized again.

The synchronization status of the channel object was full or incremental synchronization failed

• Cause: Abnormal cause Obtain the run log for viewing channel details, or click Abnormal Status in the synchronization table of abnormal status in data synchronization details to view the abnormal cause in failed data details.
• Solution: Handle the exception based on the cause. If the exception is a data problem, discard the abnormal data or retry the operation. If the fault persists, contact technical support.
• Recover: After the exception is resolved, operation synchronization starts to restore data synchronization.

The MDB service is stopped and cannot be restored after restart

• Cause: You need to view the exception information in the <./mdb-server/server.out> log file.
• Solution: If the authorization expires, apply for a new license and replace the <./license.json> file. If the fault persists, contact technical support.
• Recover: After the exception is resolved, restart the MDB service.

Frequently Exception Information

Exception Information	Cause	Solution
Online REDO LOG files or archive log files do not contain the offset scn 283058996. Please perform a new snapshot.	scn is not in the archive log file	After data synchronization is reset, data is synchronized again
FATAL: no pg_hba.conf entry for replication connection from host "27.209.10.108", user "mtk_user", SSL off	pg_hba.conf is not configured in the source database	Refer to the source database for instructions on configuring pg_hba.conf
FATAL: terminating Walsender process due to replication timeout.Detail: now time(2022-12-06 01:40:14.299346+08) timeout time(2022-12-06 01:40:14.298937+08) last recv time(2022-12-06 01:40:08.298937+08) heartbeat time(2000-01-01 08:00:00+08).Hint: try increasing wal_sender_timeout or check system time.	wal_sender_timeout parameter configuration problem	Refer to the source instructions for configuring the wal_sender_timeout parameter in postgresql.conf
ERROR: replication should connect HA port in thread_pool	The database opens the connection pool	The connection pool needs to be closed
FATAL: terminating connection due to administrator command	Database services are unhealthy	Check that the database service is working
Failed to resolve Oracle database version;ORA-01017: invalid username/password; logon denied	oracle 12c19c User has no permission	execute: alter user c##mdbuser set container_data=all container=current;