Disk contention for the CDC Replication log reader

If you are experiencing a Log Reader bottleneck on your source system it is often due to disk contention for the CDC Replication log reader.

There are several possible solutions for this type of performance issue:

• If you are using the CDC Replication Engine for Oracle databases, the CDC Replication Engine for Microsoft SQL Server, or the CDC Replication Engine for Sybase databases, it may be due to insufficient disk I/O on your source system. You can work with your system administrator to increase the available disk I/O for the database logs.
• With the CDC Replication Engine for Oracle databases, you can configure CDC Replication to only use archive logs to address this issue, although this may have an effect on latency since CDC Replication is no longer using Oracle online logs.
• With the CDC Replication Engine for Oracle databases, you can store your online and archive logs on a separate cached file system. This can improve disk I/O since disk access to the cached file system by the CDC Replication Engine for Oracle databases does not affect Oracle log writing throughput.