What does it mean? What do I do about it?
Example alert from the ProTop Portal:
What does it mean?
This tells us the number of times a process waited for an empty BI buffer. This should always be zero.
What to do?
Investigate the cause of the slowdown in BI processing:
- is the BIW running?
- is -bibufs “reasonable”? (default is 20, I usually increase it to 64 or so; a couple of hundred can be helpful during a dump & load). If it's low, increase it.
- has syncIO on the bi filesystem changed? Often, all db, ai, and bi files are written to the same file system. Does the syncIO measure include the BI file system?
- is syncIO on the bi filesystem “reasonable”?
- has the number of commits/sec changed recently?
- is there a spurt in db growth (maybe the trx/sec hasn’t changed much, but the size of the transactions is a lot bigger?
- has a new table or index become active in the update or delete trends?
Any of these items can contribute to an increase in biEmptyWt.
If all else fails...
Contact us at support@wss.com or use the online chat. We'll be happy to help.