…This can be useful if you’re trying to limit the amount of data sent over the wire, but … is brewing. Or if you watch your MySQL server’s memory usage and you see that it’s … havoc with MySQL‘s internal understanding of what’s happening on the system below. Having never experimented with GlusterFS, …
Post: MySQL and the SSB - Part 2 - MyISAM vs InnoDB low concurrency
May 22, 2013 By Leave a Comment
…Q4.1, Q4.2) but worse when small amounts of data are examined. Conclusion In some …, but there are limitations which MyISAM imposes that are difficult to work with. MyISAM does not …set fits in memory, InnoDB almost always performs better, at least for this workload. Notes MySQL version used…
Post: Galera Flow Control in Percona XtraDB Cluster for MySQL
May 2, 2013 By 5 Comments
…mysql> set global wsrep_provider_options=”gcs.fc_limit=500; gcs.fc_master_slave=YES; gcs.fc_factor=1.0″; Working with…the fc_limit Keeping the fc_limit small has two three purposes: It limits the amount of delay… A small fc_limit does however keep the certification index smaller in memory. It keeps …
Post: Memory allocators: MySQL performance improvements in Percona Server 5.5.30-30.2
April 15, 2013 By
… memory during the entire connection lifetime and free it at disconnect. If some transactions require a larger amount of memory – we just reallocate memory… glibc and jemalloc allocators. Observations: = MySQL 5.5.30 – throughput of MySQL 5.5.30 with glibc is limited first of all by inefficiency…
Post: Is Synchronous Replication right for your app?
May 14, 2013 By 18 Comments
…1), or work around it with by fsyncing to memory (Battery or capacitor-…MySQL replication from this instance, since MySQL replication is asynchronous. What about semi-sync MySQL… commit comes from!). The least amount of data we can …means more waiting, and after the limit is exceeded you will still…
Post: Modeling MySQL Capacity by Measuring Resource Consumptions
March 8, 2011 By 1 Comment
…a moment. The amount of resources system has will place a limit on amount of queries system…our estimates. If we’re running Innodb with MySQL we can use Innodb_data_reads , Innodb…compare systems with different memory amount having same workload. You will often see increasing amount of memory not only…
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 5 Comments
… have reasonable amount of connections but yet MySQL takes much more memory than you would…with MySQL 5.5 with addition of user variables, stored procedures, prepared statements etc which can be a memory hog. My intent with… allows you to limit size of MEMORY tables (the limit applies both to implicit…
Post: MySQL Wish for 2013 - Better Memory Accounting
December 31, 2012 By 6 Comments
…memory was allocated for Innodb Buffer Pool or Query Cache but amount of memory…limit memory usage by individual MySQL users or even track how much these users are using. Now as MySQL…
Post: Should we give a MySQL Query Cache a second chance ?
April 10, 2011 By 64 Comments
…which appeared in MySQL 4.0 Query Cache was designed to work with single core systems and relatively small memory amounts, both of …Cache Storage Engines MySQL Query Cache now stores queries in local memory, which is great however memory amount might be limited especially in constrained environments…
Post: MySQL Indexing Best Practices: Webinar Questions Followup
August 16, 2012 By 4 Comments
…wants to replace longish (25-30) indexed varchars with an additional bigint column containing the crc64, …of indexes. The indexes can’t fit in memory anymore. How does this affect performance? A: Typically… a hard limit on amount of indexes you can have, which is 64 per table in recent MySQL versions….
