… NIC.] The other two NIC ports should be bonded with active-backup or LACP (depending on your switching infrastructure). In essence… for the next release of MHA. Q: How do you monitor MySQL to determine when it’s not responsive? A: The easiest…: Incorrect information in file: ‘./mysql/servers.frm’ ERROR: 1033 Incorrect information in file: ‘./mysql/servers.frm’ Running mysql_install_db under strace, I…
Post: How to fix your PRM cluster when upgrading to RHEL/CentOS 6.4
May 29, 2013 By 2 Comments
… CMAN v3 is a Corosync plugin that monitors the names and number of active cluster nodes in order to deliver membership and…MySQL [p_mysql] (unmanaged) p_mysql:0 (ocf::percona:mysql): Master percona1 (unmanaged) p_mysql:1 (ocf::percona:mysql): Slave percona2 (unmanaged) p_mysql:2 (ocf::percona:mysql…
Post: How does MySQL Replication really work?
January 9, 2013 By 9 Comments
… different replication formats. These are covered pretty well in the MySQL manual here. Put simply, the events can be one of… the reason and that you can usually observe by vmstat. Monitor server activity over time and see if it is “r” or… assumes that there is no other activity happening on the server. If there is some activity, then you may also want to…
Post: Actively monitoring replication connectivity with MySQL's heartbeat
December 29, 2011 By 2 Comments
…’re actively checking the communication. How can I configure replication’s heartbeat? Is very easy to setup with negligible overhead: mysql_slave > STOP SLAVE; mysql_slave > CHANGE MASTER TO MASTER_HEARTBEAT_PERIOD=1; mysql_slave > START SLAVE; MASTER…
Post: Reasons for MySQL Replication Lag
July 29, 2011 By 9 Comments
… as swapping active and passive masters in Master-Master setup is often cause of the problem for similar reason as MySQL Restart… doing RAID validation, some centrally kicked of SAN backup, intensive activity on the other tenants sharing physical hardware with you in… involved. In could be even system which queries mysql. I’ve seen monitoring updates which would add excessively expensive and frequent query…
Post: Percona Server on the Raspberry Pi: Your own MySQL Database Server for Under $80
February 25, 2013 By 10 Comments
… Linux has this preset) Also, Arch Linux has sshd already active (sshd=ssh daemon, a software package allowing you to connect… start mysqld Connect using the mysql client: [root@alarmpi ~]# /usr/bin/mysql Welcome to the MySQL monitor. Commands end with ; or \g. [...] mysql> SHOW ENGINES…
Post: Recovery deleted ibdata1
August 10, 2012 By 9 Comments
…. For that I will delete /var/lib/mysql/ib* files, while sysbench generates read/write activity: Screen0: root@localhost:~# sysbench –num-threads… reachable: mysql> select count(*) from sbtest; +———-+ | count(*) | +———-+ | 1000000 | +———-+ 1 row in set (0.19 sec) Conclusions Add to your monitoring system checks that InnoDB files ibdata and ib_logfile* do exist Do not restart MySQL until the further…
Post: Infinite Replication Loop
October 10, 2011 By 2 Comments
… were first inserted. Another way to see it is by monitoring your MySQL server with cacti, you will immediately notice the problem… the replication on the active master (server 1): mysql> stop slave; Step 2: there are writes on the active master, the loop statements… slave position on the active master (mysql 1) is changed to the position returned by SHOW MASTER STATUS on mysql 4 (this position…
Post: MySQL extensions for hosting
April 24, 2008 By 11 Comments
… simple MySQL SHOW command it gives you the basic statistics on the database activity broken down by users, tables or indexes. Monitoring those…: 254 Other_commands: 85 Commit_transactions: 0 Rollback_transactions: 0 mysql> SHOW TABLE_STATISTICS LIKE ‘hosting2%’; +——————————–+———–+————–+————————-+ | Table | Rows_read | Rows_changed…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
… disk saturated? Is the machine swapping actively? (This is more important than …mysql –user=mysql –pid-file=/var/run/mysqld/mysqld.pid –skip-external-locking –port=3306 –socket=/var/db/mysql/mysql… the discussion to topics such as monitoring, alerting, backups, caching, reverse proxies, and …
