…. The other reason is because virtual machines tend to handle process scheduling and timing much differently than traditional hardware, and I… the manual’s description of how replication filtering rules are processed. There are some informative flowcharts in addition to the textual… occurs. For example, if you see a large number of long-running queries in the output of SHOW PROCESSLIST that might be…
Post: Is your MySQL buffer pool warm? Make it sweat!
April 16, 2013 By 6 Comments
…during peak traffic. The standby server does not process query traffic except for replication. The buffer pool…about discarded designs and benchmarks.) First, we set long_query_time to 0 in order to …will allow connection reuse. This is necessary when running a large stream of queries. Benchmarks We …
Post: Rotating MySQL slow logs safely
April 18, 2013 By 7 Comments
…signaling: Send a HUP signal to the mysqld process. Use the mysql console or mysqladmin utility … addition to logs. Flushing tables can impact running queries. Disable MySQL slow logs during rotation … -e ‘select @@global.long_query_time into @lqt_save; set global long_query_time=2000; select sleep…
Post: More on MySQL transaction descriptors optimization
April 26, 2013 By Leave a Comment
…possible to Dimitri’s environment. To put a long story short, the results are fairly consistent with…even higher QPI speed (and thus, faster inter-process/node communication). Results: First of all, we used…-index-updates=0 –oltp-non-index-updates=0 run POINT_SELECT + UPDATE QPS test sysbench –num-…
Post: Announcing Percona XtraBackup 2.1.1 GA
May 15, 2013 By Leave a Comment
… and mission-critical applications that cannot tolerate long periods of downtime. Offered free as an … –apply-log –rebuild-indexes. This allows parallel processing of individual tables when rebuilding the index. … server datadir if the server isn’t running and logs were in a separate directory. Bug…
Comment: MySQL performance: Impact of memory allocators (Part 2)
March 8, 2013 By 12 Comments
… jemalloc and tcmalloc, do much better on long-running processes at managing physical memory. For a long running process, like mysqld, glibc seems to fragment physical…
Post: TPC-H Run on MySQL 5.1 and 6.0
April 10, 2008 By 16 Comments
… Also was very slow running some queries so we changed scripts a bit to kill extremely long running queries to get results for… currently seen in MySQL 6.0 tree. There is a long way till Release and may be MySQL 6.0 performance… to use only half of system CPU resources for query processing was not too bad, however with 16,32,64 cores…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
…, ‘top -n 1′ and ‘uptime’. That shows me what processes are running, but it also shows me load average, memory sizes, and…. If the client has long-running queries, it can be pretty easy to catch. Maybe they’re long-running because they’re in Locked…’s a process of finding outliers by some criteria. Both types of queries matter. Some may be extremely fast, but run very…
Post: MySQL optimizer: ANALYZE TABLE and Waiting for table flush
February 27, 2013 By 3 Comments
… are calculated but we need to wait until the gathering process triggers again to see if there is any improvement. Usually… concurrency – A long running query – Run an ANALYZE TABLE on a table accessed by the long running query So first we need a long running query against… are dealing with a write query on InnoDB the rollback process could take even more time to finish than the original…
Post: How fast is FLUSH TABLES WITH READ LOCK?
April 24, 2010 By 30 Comments
…. That means that every currently running query, including SELECT queries, must finish. So if there is a long-running query on the system, or an open transaction or another process that holds a table lock… example of what the system can look like while this process is ongoing: mysql> show processlist; +—-+——+———–+——+————+——+——————-+———————————————————————-+ | Id | User | Host | db | Command…
