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  1. MariaDB MaxScale
  2. MXS-2643

Maxscale causal_reads and Mariadb percona cluster timeout

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      In a Mariadb cluster (4 node) with gtid mode on we have problems with causal_reads. After an insert, the next query waits until the causal_reads_timeout reaches its maximum value. We are not sure if this problem comes from Maxscale or Percona.

      Steps to reproduce:

      CREATE TABLE `test_lrl`.`test` (
      `id` INT NOT NULL AUTO_INCREMENT,
      `text` VARCHAR(45) NULL,
      PRIMARY KEY (`id`));

      SELECT id,text,@@HOSTNAME FROM test_lrl.test;
      12:39:43 SELECT id,text,@@HOSTNAME FROM test_lrl.test LIMIT 0, 1000 3 row(s) returned *0,0094 *sec / 0,000017 sec

      INSERT INTO `test_lrl`.`test` (`text`) VALUES ('Test');

      SHOW SESSION VARIABLES WHERE Variable_name = 'last_gtid';
      maxscalen1:> 'last_gtid', '1-1-480601'

      Mariadb nodes: SHOW GLOBAL VARIABLES LIKE 'gtid_current_pos';
      n1:> 'last_gtid', '1-1-480639'
      n2:> 'last_gtid', '1-1-480639'
      n3:> 'last_gtid', '1-1-480639'
      n4:> 'last_gtid', '1-1-480639'

      SELECT id,text,@@HOSTNAME FROM test_lrl.test;
      12:41:10 SELECT id,text,@@HOSTNAME FROM test_lrl.test LIMIT 0, 1000 4 row(s) returned *20,014 *sec / 0,000015 sec
      '13', 'Test', 'db-c01-n3'

      Mariadb nodes:
      n1:>
      n2:> Waiting in MASTER_GTID_WAIT() (primary waiter) | SET @maxscale_secret_variable=(SELECT CASE WHEN MASTER_GTID_WAIT('1-1-480601', 20) = 0 THEN 1 ELSE (SELECT 1 FROM INFORMATION_SCHEMA.ENGINES) END)
      n3:>
      n4:>

      Config Maxscale:

      --------------------------------------------------------------------
      Server | Address | Port | Connections | Status
      --------------------------------------------------------------------
      db-c01-n1 | 10.1.1.162 | 3306 | 2 | Slave, Synced, Running
      db-c01-n2 | 10.1.1.163 | 3306 | 1 | Slave, Synced, Running
      db-c01-n3 | 10.1.1.164 | 3306 | 4 | Master, Synced, Running
      db-c01-n4 | 10.1.1.165 | 3306 | 1 | Slave, Synced, Running
      --------------------------------------------------------------------

      [galera-service]
      type=service
      router=readwritesplit
      servers=db-c01-n1,db-c01-n2,db-c01-n3,db-c01-n4,
      user=maxscale
      password=******
      localhost_match_wildcard_host=1
      use_sql_variables_in=master
      max_sescmd_history=0
      disable_sescmd_history=true
      filters=NamedServerFilter
      max_slave_connections=1
      slave_selection_criteria=LEAST_GLOBAL_CONNECTIONS
      causal_reads=1
      causal_reads_timeout=20

      [NamedServerFilter]
      type=filter
      module=namedserverfilter
      match01=.temp\..
      target01=->master
      match02=.`temp`\..
      target02=->master

      Galera cluster:
      [mysqld]
      binlog_format=ROW
      innodb_autoinc_lock_mode=2
      bind-address=0.0.0.0

      wsrep_on=ON
      wsrep_provider=/usr/lib64/galera/libgalera_smm.so

      wsrep_cluster_name="mariadb-c01-test"
      wsrep_cluster_address="gcomm://db-c01-n1,db-c01-n2,db-c01-n3,db-c01-n4"

      wsrep_sst_method=mariabackup
      wsrep_sst_auth=replication:******

      wsrep_node_address="10.1.1.162"
      wsrep_node_name="db-c01-n1"

      1. Settings for gtid cluster ():
        wsrep_slave_threads=8
        wsrep_gtid_mode=ON
        wsrep_gtid_domain_id=1
        log_slave_updates=ON
        log_bin=db-c01
        expire_logs_days=1
        session_track_system_variables=autocommit,character_set_client,character_set_connection,character_set_results,time_zone,last_gtid

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              Assignee:
              markus makela markus makela
              Reporter:
              powercycle Leon Ruumpol
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                Created:
                Updated:
                Resolved: