Oracle Metric log file sync

This post is mainly to make other people aware that on a RAC system there is a relationship between high inter-node block sharing traffic (Global Cache) and “log file sync”, and that the log file sync events are a direct side effect of the high inter-node block sharing that is occurring.

This occurs when a user commits a transaction (a transaction is not considered committed until all of the redo to recover the transaction has been successfully written to disk).

In single instance database  when we issue commit it just write log buffer into redo log file but in RAC database there is little more to it, it will perform the same operation and broadcast this commit info to other remote LMS and waits for acknowledgement from them. once it gets acknowledgement from remote lms only then commit gets completed.Untitled


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s