SQL causing 100% CPU utilization

#11

Steven Holland wrote:

Quote:

You guys are right. Here's what I found out.

Looking at the AWR report closer I noticed a back ground wait event
that caught my eye that I missed before. The 'rdbms ipc message'
metric was too high. The event rdbms ipc message indicates that a
process is waiting for a message to arrive on his message queue. The
number of message blocks parameter was set too small. If a process
needs a message it will get the latch, search a linked list for a free
message block, unlink this message block , put this message on the
message queue for the intended process and then release this latch.
indicated If a process needs a message it will get the latch, search a
linked list for a free message block, unlink this message block , put
this message on the message queue for the intended process and then
release the latch. The event rdbms ipc message indicates that a
process is waiting for a message to arrive on his message queue. The
event rdbms ipc message reply is used to indicate that a message is
expected back by the sending process."

So....The process was pegging the CPU requesting a message block from
the LRU list in the SGA but ran into latch contention. The latch
contention also caused contention with the rollback process.

Steven, you really have to take it easy with acid. You should read your own messages once
you're clean, you'll see what I mean.

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SQL causing 100% CPU utilization

comp.databases.oracle.misc comp.databases.oracle.misc

Re: SQL causing 100% CPU utilization - 05-10-2011 , 12:45 PM