…query_alloc_block_sizeblogpercona.commanual query_cache_limitblogpercona.commanual query_cache_min_res_unitblogpercona.commanual query_cache_sizeblogpercona.commanual query_cache_typeblogpercona.commanual query_cache_wlock_invalidateblogpercona.commanual query…
Post: State of MySQL Market and will Replication live ?
April 9, 2008 By 29 Comments
… these things few things happen – MySQL kept being “simple” and introduced relatively simple performance boosters – Query Cache and Replication, which were clearly not enough to solve all performance problems (like scaling Writes with replication or dealing with…
Post: Reasons for MySQL Replication Lag
July 29, 2011 By 6 Comments
…cache content. Replication Traffic Changes Changing in the replication traffic (what updates are being replicated) are frequent cause of concern. Remember replication…replication lag. Same may happen with operating system and other system software involved. In could be even system which queries mysql…
Post: Estimating Replication Capacity
July 20, 2010 By 4 Comments
… include all queries MySQL server ran with their times and run mk-query-digest with filter to only check queries from replication thread: mk-query-digest…” vs “hot” replication capacity as well as how long replication warmup takes. It is very typical for servers with cold cache to perform…
Post: MySQL Replication vs DRBD Battles
April 28, 2008 By 12 Comments
…memory and CPU cycles on double caching. Even in this case DRBD …the same time as running reporting queries on last month. All last month…MySQL Replication, such as filtered replication or cross storage engine replication, though which are not typically used for HA purposes. Time Delayed replication…
Post: MySQL MyISAM Active Active Clustering - looking for trouble ?
March 15, 2007 By 4 Comments
… can use MySQL with Active Active Clustering and MyISAM tables if you follow certain rules like enabling external locking, disabling query cache and… well performing compared to other setups, ie replication based. If you can’t use replication because it is async and your load… really being compatible with such setup. As Oli describes even query cache which was implemented many years ago in 4.0 was…
Post: MySQL Crash Recovery
July 30, 2006 By 26 Comments
… out of sync with database content. This will sometimes break replication but if you’re just planning on using binary log… – If you restart MySQL server its caches (key_buffer, innodb_buffer_pool, query_cache,table_cache) are cleaned, so may be OS caches. This may reduce… large index scan queries. Full table scan queries allow to preload table data ether in storage engine caches or in OS cache. You can…
Post: Shard-Query EC2 images available
May 11, 2011 By 2 Comments
… ./run_query command, called pivot_results cd shard-query/ $ ./run_query < queries.sql | tee …-update-relay-log innodb-replication-delay=# innodb-rollback-on-…cache=16384 table-open-cache=128 thread-cache-size=32 thread-stack=256K tmp-table-size=64M transaction-isolation=READ-COMMITTED user=mysql…
Post: Top 5 Wishes for MySQL
June 29, 2007 By 10 Comments
… not think MySQL Cluster would ever be that thing as it provides too strong guarantees. It is same as with MySQL Replication – the…. I’m saying about Prepared Statements in MySQL 4.1 which came without query cache support but even worse not all of statements… for very long time. For example Query Cache support for Prepared Statements is only fixed in MySQL 5.1 and Most of other…
Post: MySQL Server Variables - SQL layer or Storage Engine specific.
June 8, 2006 By 14 Comments
…and HEAP for in memory tables. So first MySQL versions did not bother naming variables with …is MyISAM related. expire_logs_days This is replication/binlogging related options – when to delete binary … MyISAM and Innodb. Some SQL level items as Query Cache also could use this feature. low_priority_…
