… anything you find in standard async MySQL replication. It is my belief …purposes: It limits the amount of delay any node in the cluster … which translates into number of unique key lookups into the certification index, …slaves with no writes coming from them. However, with multi-node writing, larger …
Comment: MySQL Partitioning - can save you or kill you
April 30, 2013 By 45 Comments
…) anywhere in any ‘free’ variant of MySQL. PARTITIONs are scanned one at a time…non-partition equivalent. Even single-row writes are likely to be slower …row based on a UNIQUE/PRIMARY key and it can prune, the delete … also BTrees, so they need updating (although delayed). Yes, their BTrees may be one…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…delay_key_writeblogpercona.commanual Delayed_errorsblogpercona.commanual delayed_insert_limitblogpercona.commanual Delayed_insert_threadsblogpercona.commanual delayed_insert_timeoutblogpercona.commanual delayed_queue_sizeblogpercona.commanual Delayed_writesblogpercona.commanual des_key…
Post: MySQL Server Variables - SQL layer or Storage Engine specific.
June 8, 2006 By 14 Comments
…MySQL versions did not bother naming variables with storage engines prefix. This is why we have key_buffer, not “myisam_key…delay_key_write Delay updating indexes for MyISAM tables. Good for performance but tables will be badly corrupted on crash. delayed_insert_limit, delayed_insert_timeout, delayed…
Post: MySQL MyISAM Active Active Clustering - looking for trouble ?
March 15, 2007 By 4 Comments
… MySQL with Active Active Clustering and MyISAM tables if you follow certain rules like enabling external locking, disabling query cache and delayed key writes… overhead you get from external locking. Plus key cache have to be invalidated with remote writes which makes even less efficient. So…
Comment: How to decrease InnoDB shutdown times
April 16, 2009 By 20 Comments
… with the MySQL support team. delay_key_write=ON http://dev.mysql.com/doc/refman/5.0/en/server-options.html#option_mysqld_delay-key-write This global configuration variable can be used (delay_key_writes=ALL) to stop writes from the MySQL key buffer to disk. It…
Post: Using MyISAM in production
June 17, 2006 By 36 Comments
… into trouble. Just one is enough. Lock priorities. By default MySQL treats updates as higher priority operations. You can use SELECT… wipe OS cache which you hoped for causing unexpected slowdowns. delay_key_writes Whatever way you enable this option – globally, for table or… been running for years survining many crashes. If you enable delay_key_writes it drastically changes. Now in case of crash your index…
Post: Percona XtraDB Cluster: Multi-node writing and Unexpected deadlocks
August 17, 2012 By 17 Comments
… alternative to traditional MySQL replication. For those who don’t know, it gives you: Fully Synchronous replication with a write latency increase… restores The ability to read and write on every node without needing to worry about replication delay However, good engineers know there… NULL AUTO_INCREMENT, `j` varchar(32) DEFAULT NULL, PRIMARY KEY (`i`) node2 mysql> insert into autoinc (j) values (‘node2′ ); Query OK, 1…
Comment: Using MyISAM in production
June 19, 2006 By 36 Comments
Kevin, Yes Idea of using delay_key_write on slave servers is good one. You want to do … cache problem is actually partialy solved by using MMAP in MySQL 5.1 but you still can’t configure its size…
Post: Investigating MySQL Replication Latency in Percona XtraDB Cluster
March 3, 2013 By 13 Comments
… the script doing writes to DPE1 and immediately reading from DPE2 Summary: 94 out of 10000 rounds (0.94%) Delay distribution: Min… much more frequently in almost 40% though the average observed delay remains just few milliseconds, which is something most applications would… Writes. We can do it with Sysbench, for example: sysbench –test=oltp –oltp-test-mode=nontrx –oltp-nontrx-mode=update_key –mysql-user…
