0

The setup I have is a master/slave replication, both running Mariadb 10.1.13.

On the slave I noticed that the Seconds_Behind_Master parameter is showing a delay due to some form of lagging, but the values for Master_Log_File and Relay_Master_Log_File are the same.

I have checked that the server IDs are different, however both have the same gtid_domain_id. 

               Slave_IO_State: Waiting for master to send event
                  Master_Host: X.X.X.X
                  Master_User: repl
                  Master_Port: 3321
                Connect_Retry: 60
              Master_Log_File: binary_.005825
          Read_Master_Log_Pos: 140625151
               Relay_Log_File: mysql20-relay-bin.000145
                Relay_Log_Pos: 138885256
        Relay_Master_Log_File: binary_.005825
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
              Replicate_Do_DB: 
          Replicate_Ignore_DB: 
           Replicate_Do_Table: 
       Replicate_Ignore_Table: 
      Replicate_Wild_Do_Table: 
  Replicate_Wild_Ignore_Table: 
                   Last_Errno: 0
                   Last_Error: 
                 Skip_Counter: 0
          Exec_Master_Log_Pos: 138884970
              Relay_Log_Space: 1214370105
              Until_Condition: None
               Until_Log_File: 
                Until_Log_Pos: 0
           Master_SSL_Allowed: No
           Master_SSL_CA_File: 
           Master_SSL_CA_Path: 
              Master_SSL_Cert: 
            Master_SSL_Cipher: 
               Master_SSL_Key: 
        Seconds_Behind_Master: 10056
Master_SSL_Verify_Server_Cert: No
                Last_IO_Errno: 0
                Last_IO_Error: 
               Last_SQL_Errno: 0
               Last_SQL_Error: 
  Replicate_Ignore_Server_Ids: 
             Master_Server_Id: 21
               Master_SSL_Crl: 
           Master_SSL_Crlpath: 
                   Using_Gtid: Slave_Pos
                  Gtid_IO_Pos: 0-20-34183339144
      Replicate_Do_Domain_Ids: 
  Replicate_Ignore_Domain_Ids: 
                Parallel_Mode: conservative

Any advice on solving the lag between my master/slave setup would be appreciated. What could the root cause be?

Improve this question
1
  • Well.. i did not know mariadb/mysql that much, but i think this is related to network.. if you don't want to see any kind of delay from master to slave, maybe you want to setup synchronous or semi-synchronous replication... but this will make master slow down, try something like iptraf-ng to monitor your network and see how much mysql/mariadb is needing speed... and most important, be sure the hardwares are the same in master and slave. if you are not sure atop (not htop) can show you with more precision hardware issues like a I/O problem. If that helps please let me know to post as answer
    – Luciano Andress Martini
    Commented Sep 25, 2018 at 11:53

1 Answer 1

Reset to default
0

140625151 and 138884970 are not that close. But 10056 seconds is a nearly 3 hours. What query is the Slave executing? Maybe a long-running ALTER?

There have been cases where Seconds_behind_master bounces between 0 and some large value; is that happening?

Improve this answer

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.