On Thu, Mar 20, 2014 at 4:12 AM, Shaun Duncan <shaun.dun...@gmail.com>wrote:
This is on a production 9.0.15 install with 1 master, 5 hot standby read > only slaves. > > We've been trying to look into a situation where we're seeing that hot > standby read slaves are receiving WAL segments, but are exceeding > max_standby_archive_delay (60s) and max_standby_streaming_delay (60s) and > not applying changes. The slave will get the first segment and hang (we've > seen up to 30m before removing the slave from our read pool to catch up) > and get further and further behind the master. Furthermore, we have seen > that after a slave has caught up, putting it back into the read pool will > mean will almost immediately start to see this happen again. It acts as if > we had max_standby_* set to -1. > > I'm just looking for some ideas, hints, or suggestions as to what might be > going on here or what we might be doing wrong. > > Have you noticed if the read requests on standby database are taking long and loading up the server ? If yes, any idea why the queries on standby are taking long to complete ? WAL replay would be paused ( until the read requests are served ) at the time of conflicting queries on the standby site. Also, Do you see any delay in master sending the WALs to standby ? Venkata Balaji N Sr. Database Administrator Fujitsu Australia
