… Dictionary cache 512619219 (509995888 + 2623331) File system 294352 (82672 + 211680) Lock system 318875832 (318747272 + 128560) Recovery system 0 (0 + 0) Threads 425080 (406936… total any more as Innodb has moved allocating memory from operation system directly not from addition memory pool (hence 0). Such allocations… and fixed. This is where your MySQL Support contract can be handy. Conclusion Understanding where MySQL can allocate memory can help us…
Post: Getting MySQL Core file on Linux
August 26, 2011 By 1 Comment
… to /var/lib/mysql (datadir) on my system (Ubuntu). You might be lucky and it might work in your system. I also enable… same operating system. This is important. There have been many changes to core file handling on Linux and what worked on one system…/sbin/mysqld[0x516a61] The manual page at http://dev.mysql.com/doc/mysql/en/crashing.html contains information that should help you…
Post: MySQL Performance Engineer opening
May 13, 2008 By Leave a Comment
… to analyze performance of various MySQL features, benchmark, compare, analyze things and post our findings on MySQL Performance Blog. However recently we… should have an “evil mind” to be able to put system in the conditions developers would not think about. One should… an “X-Ray vision” understanding what happens on all layers (MySQL, Operation System, Hardware) when for example row is being inserted into Innodb…
Post: Announcing PAM authentication plugin for MySQL (early access release)
December 5, 2011 By 9 Comments
… access version of Percona’s PAM Authentication plugin for MySQL. This plugin supports MySQL-5.5.x, Percona Server 5.5.x…. The PAM Authentication plugin can be used for: MySQL authentication using operating system users (pam_unix) MySQL authentication from LDAP server (pam_ldap) authentication…
Post: Stripped MySQL builds, the optimization that isn't
December 7, 2010 By 7 Comments
I usually tell people to use official MySQL builds from MySQL, or from their operating system distribution if they don’t want to do…, it’s far too easy to subtly mess up a MySQL build and really end up with a problem.
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
… good idea what hardware and operating system I’m working with. System performance Next I investigate what the system is doing, in terms of performance. There are two key commands for this on most operating systems (there are…=/var/db/mysql –user=mysql –pid-file=/var/run/mysqld/mysqld.pid –skip-external-locking –port=3306 –socket=/var/db/mysql/mysql.sock consult…
Post: Why you should ignore MySQL's key cache hit ratio
February 28, 2010 By 28 Comments
… operating system‘s cache, then a Key_read is a disk read — but if it is cached, then it’s just a system…’s doing. But alas, that’s virtually impossible on most systems I work on. So there you have it — yet another…-second intervals and compare the results to your IO system‘s capabilities. MySQL doesn’t have good instrumentation for scientifically choosing a…
Post: Implications of Metadata Locking Changes in MySQL 5.5
February 1, 2013 By 9 Comments
… | 0.000058 | | checking permissions | 0.000006 | | Opening tables | 213.028481 | | System lock | 0.000009 | | init | 0.000014 | | optimizing | 0.000002 | | statistics… query to a table that has a DDL operation waiting, will block. Why? Because MySQL sees that the old entries in the… | 0.000059 | | checking permissions | 0.000010 | | Opening tables | 53.786685 | | System lock | 0.000009 | | init | 0.000012 | | optimizing | 0.000003 | | statistics…
Post: The #1 mistake hosting providers make for MySQL servers
July 25, 2008 By 30 Comments
…/Linux operating systems on 64-bit hardware. This is a serious mistake. You have to tell them to install a 64-bit operating system… gladly install 8 or 16GB of memory for you, but MySQL can’t use it because it runs in a single… of memory. And then you have to rebuild the whole operating system from scratch. But you don’t want any downtime, so…
Post: MySQL Server Memory Usage
May 17, 2006 By 21 Comments
… of Operation System cache you would like MySQL to use for your table. Take this number add to it number of memory Operation System and other applications need, add might be 32MB more for MySQL Server code and various small…_table_size is rather maximum amount of memory MySQL will allocate for this operation. Note it is more complicated than once may…
