Re: Replication Lag

Steve Crawford <scrawford@xxxxxxxxxxxxxxxxxxxx> · Fri, 21 Mar 2014 17:44:08 -0700



    On 03/21/2014 12:43 PM, Chatha, Karan
      (CMG-Atlanta) wrote:

    
        1)     
              It was working until March 8
      
    
    And then what changed? *Anything* that might have happened. Config
    change, unclean reboot, out of disk, firewall updates, network
    changes, anything at all...

    
        2)     
              We upgraded Postgres from 9.03 to
            9.015 on Feb 19
      
    
    There are a few items that require special handling between 9.03 and
    9.0.15. Did you read all the release notes and make sure that the
    extra steps were completed or didn't apply to you? (I'm not sure
    that any directly impact replication but haven't been running
    anything earlier than 9.1 for quite a while.)

    
        3)     
              Streaming Replication
        4)     
              Right now we have master on 9.015 and
            7 slaves on 9.015 and one slave on 9.0.16
        5)     
              We have full logging enable to syslog
      
    
    What do the logs tell you? Have you thoroughly examined them both
    for current messages and anything unusual around the time that the
    issue appeared?

    
        6)     
              What we see is that there are no loads
            or io but archives get stuck on one archive.  We have
            
        7)     
            max_standby_archive_delay =
          60000               # max delay before canceling queries
        max_standby_streaming_delay = 60000
         
        It is almost like these values are
          not being honored.
      
    
    Cheers,

    Steve