Global Data Management Forum

Hi 

i'm using InfoSphere Data Replication, when i update field in primary informix database IDR agent not commit to secondary but when i increase number of commit it will sync primary with secondary.

now question is how can sync even small number of commits on primary sync to secondary. Seems it will sync bulk of data, e.g. when i have 2000 commit it will sync primary and secondary.

FYI: when i restart IDR it will sync even small changes to secondary.

any idea?

Thanks

What you are seeing is something typically seen in small test environments where the amount of log data being generated is extremely small.   Making and committing a change to the source does not make it imediately available to be captured.   This is something that is typically controlled by the source database, Informix in this case.  I am very familiar with how the log data is made available from a Db2 for z/OS source to IIDR and I imagine that the process is similar for Informix.   The Capture process/service communicates to the source database using an API interface defined by the source database.   The source database typically processes the data from the database internal log buffers AFTER A LOG BUFFER IS FILLED, or when a database system CHECKPOINT occurs.   So in a system where only a single update was performed over a period of time, that is not enough log data to fill the database log buffer and as such, a delay will be seen in your latency.  As you issue multiple commits, that causes log data to be written, eventually filling the log buffer and making the changed data available to the API to provide to IIDR. 

Contrast that with a production system with an ongoing volume of workload, the log buffers will fill quickly and thus the changes made available more immeidately as well. 

Hope this explanation helps.