Preventing DDRBLOCK and log wrap

Prevent Enterprise Replication (ER) from entering a transaction blocking state, known as DDRBLOCK mode.

When a logical log wraps, it overwrites transactions that ER has not yet processed. The transactions are lost before they are stored in the send queue. If a database server is approaching log wrap, ER enters DDRBLOCK mode. ER can be configured to add a logical log file dynamically instead of entering DDRBLOCK mode.

To monitor proximity to DDRBLOCK, on the menu of the HCL OpenAdmin Tool (OAT) for Informix®, click Replication > Node Details > Capture. Review the Proximity to DDRBLOCK field, which displays the number of pages in the logical log space until ER enters DDRBLOCK.
To prevent DDRBLOCK, configure ER to add logical log files dynamically. On the OAT menu, click Replication > Node Details > Configure, and set the DYNAMIC_LOGS and CDR_MAX_DYNAMIC_LOGS parameters.
To monitor proximity to log wrap, on the OAT menu, click Replication > Node Details > Capture. Review the Proximity to Log Wrap field, which displays the number of pages in the logical log space until the logical log wraps.