…slave lag is that you often can’t see it coming. Especially if the slave‘s load is pretty uniform, a slave…mysql_system# TOTAL_CONNECTIONS: 1 CONCURRENT_CONNECTIONS: 2 CONNECTED_TIME: 46188 BUSY_TIME: 719 ROWS_FETCHED: 0 ROWS_UPDATED…
Post: How expensive is MySQL Replication for the Master
January 16, 2010 By 13 Comments
…MySQL replication as being quite low overhead on Master, depending on number of Slaves. What kind of load extra Slave…slave were to be woken up to send the update notification. With 4 slaves…slave no more often than 1000 times a second and each wake up even would send multiple events to the slave…
Post: Finding your MySQL High-Availability solution – Replication
November 13, 2009 By 6 Comments
… of MySQL replication which does not allow the master to be sure the slave has been updated… the availability of the MySQL replication link between the servers. Replication often break for various reasons…availability of this solution is affected by how much the slaves were behind the master when the …
Post: MySQL Query Cache
July 27, 2006 By 70 Comments
…being invalidated from query cache by table updates, this means number of queries …application – You can’t change how it works with MySQL to add caching but you… control on invalidation Table granularity is often too bad. With other caches … not distributed If you have 10 slaves and use query cache on …
Post: Recovery beyond data restore
August 2, 2008 By 11 Comments
…they should be on promoted slave and slave should have –log-slave-updates enabled so it somethat … you have to deal with (which often can be resolved by doing recovery …MySQL bugs or wrong use. Interesting enough very few people have their data recovery practices ironed out so they can answer how…
Post: Updated msl (microslow) patch, installation walk-through!
April 20, 2008 By 17 Comments
… there have been no updates to our msl patch, however recently …. We ourselves often rely on it when doing commercial MySQL consulting and MySQL AB has…is. First you should determine how your current MySQL installation was built, so you…/set_var.h patching file sql/slave.cc patching file sql/sql_cache…
Post: How would you compress your MySQL Backup
June 5, 2008 By 29 Comments
… done on physical level here (cold backup, slave backup, innodb hot backup or snapshot backup) … Though in this example we used MySQL binary log file which often contains plenty of similar events, … static overhead naturally added. UPDATE: It looks like people are wondering how BZIP2 compares so I …
Post: Estimating Replication Capacity
July 20, 2010 By 4 Comments
… providers which often have very…mysql> select * from information_schema.user_statistics where user=”#mysql_system#” \G *************************** 1. row *************************** USER: #mysql…for the slave I/O thread to update it | NULL | | 802354 | root…capacity as well as how long replication …
Post: Rendundant Array of Inexpensive Servers
August 21, 2008 By 15 Comments
… to design highly available MySQL powered system… how do you approach that ? Too often I see the …MySQL Replication for HA) the switch to the new server may not be 100% clean with few updates…using RAID0 for slaves – in these cases there are typically many slaves and recovery of the slave is …
Comment: Database problems in MySQL/PHP Applications
August 11, 2006 By 13 Comments
… > one database per table that often. I however often see applications > using multiple databases … > Things are different with MySQL. Good design will help dictate how many tables are required …updates, and deletes but there are other benefits. Also – if you’re replicating from a master to a slave…
