5.7.9. Troubleshooting Oracle CDC Deployments

The following guides provide information for troubleshooting and addressing problems with Oracle deployments.

  • Extractor Slow-down on Single Service

    If when replicating from Oracle, a significant increase in the latency for the extractor within a single service, it may be due to the size of changes and the data not being automatically purged correctly by Oracle.

    The CDC capture tables grow over time, and are automatically purged by Oracle by performing a split on the table partition and releasing the change data from the previous day. In some situations, the purge process is unable to acquire the lock required to partition the table. By default, the purge job does not wait to acquire the lock. To change this behavior, the DDL_LOCK_TIMEOUT parameter can be set so that the partition operation waits for the lock to be available. For more information on setting this value, see Oracle DDL_LOCK_TIMEOUT.

5.7.9.1. ORA-00257: ARCHIVER ERROR. CONNECT INTERNAL ONLY, UNTIL FREED

Last Updated: 2016-04-20

Condition or Error

It is possible for the Oracle server to get into a state where Tungsten Replication is online, and with no other errors showing in the log. However, when logging into the Oracle server an error is returned:

ORA-00257: ARCHIVER ERROR. CONNECT INTERNAL ONLY, UNTIL FREED

Causes

  • This is a lack of resources within the Oracle server, and not an issue with Tungsten Replication.

Rectifications

  • The issue can be addressed by increasing the logical size of the recovery area, by connecting to the Oracle database as the system user and running the fol\ lowing command:

    shell> sqlplus sys/oracle as sysdba
    SQL> ALTER SYSTEM SET db_recovery_file_dest_size = 80G;