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Showing posts from January, 2009

The case of the small log file and the CS_EVENT_WAIT (BIO)

New years eve.The standard procedure every year.
At the client's side the ABF application is doing some intense querying
(selects and deletes) and hangs for quite some time.

The first thing that springs in mind is that there is another query that blocks.
Looking at the sessions using IPM, the session in question was in
CS_EVENT_WAIT (BIO) state so there was no blocking.

CS_EVENT_WAIT (BIO) means the session is waiting for a message to be received from or sent to the user interface.
What is that message? the application was there waiting for something!

After investigation and doing some admin work the guilty party was found!
It was the Ingres log file!
It was set by the client to 80MB (!!) and every transaction is writing there
data for undo/rollback blocks;since the log file had not enough room the transactions were queing.

So the installation had to be brought down and the log file incremented to a few GB
and the issue was resolved.

Fortunately, since I did not want to spent new year's at…