Re: Replication Issues

Achilleas Mantzios <achill@xxxxxxxxxxxxxxxxxxxxx> · Fri, 28 Sep 2018 09:29:10 +0300



    On 28/9/18 9:00 π.μ., bhargav kamineni
      wrote:

    
        Hi Team,
          

          I have configured replication using slot ,But it failed
            by throwing the ERROR  pg_basebackup:
              could not get transaction log end position from server:
              ERROR:  requested WAL segment 0000000100002C9D00000085 has
              already been removed , which is  unexpected
              because i have created the slot on master first and then
              issued the base backup command from slave's end 
          the
              command is 
          usr/lib/postgresql/9.5/bin/pg_basebackup
                -U  user --max-rate='150 M' --progress --verbose
                --write-recovery-conf --status-interval='10 s' -D
                data_dir  -h host_ip  -p 5433

            
    Either :

    add  "-X stream" to the pg_basebackup command

    or

    increase wal_keep_segments on the server.

    
          These 
              are the settings on my master 
          archive_mode=on
          archive_command='/bin/true'
          wal_keep_segments=512
        max_wal_senders=4
        Series of steps i have followed :
        1) Enabled password less authentication between master and
          slave 
        2)created slot on master (assuming it will store wal's
          regardless of other settings)
        3)started basebackup from slave's end
        4)Issued checkpoint at master's end
        

        Here my concern is , slave should recover WAL from
          replication slot but why i got the above ERROR , Why slot
          removed  the requested wal file , Could you please let me know
          the reason why it happened or did i miss something ?
        

        Thanks,
        Bhargav K
        

    -- 
Achilleas Mantzios
IT DEV Lead
IT DEPT
Dynacom Tankers Mgmt