DSNB764I DUPLEXING STATISTICS FOR secondary-gbpname WRITES FAILED DUE TO LACK OF STORAGE = s2 ASYNC COMPLETION CHECKS = s3

If the DISPLAY GROUPBUFFERPOOL command included the MDETAIL option and the group buffer pool is duplexed, the output includes statistics on requests and writes to the secondary group buffer pool.

DSNB764I - DUPLEXING STATISTICS FOR secondary-gbpname
             WRITES
               FAILED DUE TO LACK OF STORAGE           = s2
               ASYNC COMPLETION CHECKS                 = s3
DSNB793I -   DELETE NAME LIST                          = s5
             READ CASTOUT STATISTICS                   = s6
             DELETE NAME                               = s7
             OTHER ASYNCHRONOUS GBP REQUESTS           = s8   

secondary-gbpname

The secondary group buffer pool name. This name is the primary group buffer pool name (such as GBP0) suffixed with -SEC.

s2

The number of times that a write request from the coupling facility did not complete because the secondary group buffer pool did not have enough storage.

s3

The number of times that Db2 checked whether a changed page was written to the secondary group buffer pool, but the write operation was not yet complete. Thus, the transaction had to wait until the write to the secondary group buffer pool completed.

s5

The number of requests to delete from the secondary group buffer pool a set of pages that were recently cast out from the primary group buffer pool. If the group buffer pool was duplexed for the entire reporting interval, this number should be roughly equal to the number of UNLOCK CASTOUT requests, as reported in message DSNB796I.

s6

The number of requests to check for orphaned data entries in the secondary group buffer pool. Orphaned data entries are changed data entries in the secondary group buffer pool without a corresponding changed data entry in the primary group buffer pool.

The group buffer pool structure owner periodically issues these requests to determine whether orphaned data entries in the secondary group buffer pool need to be cleaned up. Orphaned data entries are expected periodically and do not indicate a data inconsistency problem. Orphaned data entries can be introduced by certain transaction or system failures or by the unlikely circumstance that new group buffer pool write activity occurred concurrently with castout processing.

s7

The number of requests to delete orphaned data entries from the secondary group buffer pool. The group buffer pool structure owner issues these requests if it determines that orphaned data entries need to be cleaned up.

s8

The number of asynchronous coupling facility requests that were sent to the secondary group buffer pool. This number excludes the s3 value.

Related information

• Characteristics of primary and secondary structures
• How Db2 writes from the group buffer pool to disk