One of the very frequent cases with performance problems with MySQL is what they happen every so often or certain times. Investigating them we find out what the cause is some batch jobs, reports and other non response time critical activities are overloading the system causing user experience to …
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 3 Comments
… for processing). Of course you will see these tables going away if you close connection. In Percona Server you can do… of the lines below. The most likely cause for Innodb run away memory allocation is Dictionary cache though there could be other… in MySQL. Most suspected memory leaks end up being some run away resource usage, though these can happen. Some memory leaks might…
Post: How FLUSH TABLES WITH READ LOCK works with Innodb Tables
March 23, 2012 By 20 Comments
… in set (0.00 sec) As result this means single run away select can effectively cause downtime if you use backup solution… TABLES WITH READ LOCK and fail backup or kill long running SELECT queries to let backup to proceed, but resolving server…
Post: Win Free MySQL Conference Tickets!
March 14, 2012 By 2 Comments
We’re giving away three full conference passes (worth $995 each) to the Percona … to be there — and that’s why we’re giving away free tickets and books, and making it easy for you… may give your prize to someone else instead The contest runs from now (March 15th, depending on your timezone) through the…
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
….5. Note that query cache is disabled during these benchmark runs and that the disks are 4 5.4K disks in…_orderkey 2 100.00 Using where So during cold query runs the optimizer would switch to using plan ‘a’, which does… able to do many read_aheads. Another thing to take away is that MariaDB is just a bit slower as compared…
Post: Reasons for run-away main Innodb Tablespace
June 10, 2010 By 1 Comment
… transactions this is a very good indicator. If you’re running Percona Server the following can be helpful: mysql> select * from… 3 reasons a lot of undo space may be required: Running Transaction which does a lot of changes – If transaction modifies… as it internally commits every 10000 rows. Running Very Long Transaction If you’re running very long transaction, be it even SELECT…
Comment: How to Identify Bad Queries in MySQL
January 11, 2011 By 16 Comments
… be determined easily. You can get away with a slow system, but when customers start to run away, you’re too late for… to the system, or 3. they block other queries from running ” is useless to me. What is your definition of slow…
Post: Watch out for your CRON jobs
October 14, 2009 By 19 Comments
… I have found about 80 copies of same cron job running hammering the database. This number is rather extreme typically the… with run away cron jobs is way to frequent. If slow down happens on the database server or job takes longer to run… to happen – for example if job failed to run because other one is running which is not expected in your system. In…
Post: Thinking about running OPTIMIZE on your Innodb Table ? Stop!
December 9, 2010 By 13 Comments
… not be best way to do it. If you’re running Innodb Plugin on Percona Server with XtraDB you get benefit… Duplicates: 0 Warnings: 0 That’s right ! Optimizing table straight away takes over 3 hours, while dropping indexes besides primary key… compact index in the end. So if you’re considering running OPTIMIZE on your tables consider using this trick, it is…
Comment: Too many connections? No problem!
March 23, 2010 By 28 Comments
… to be *very* quick to get your connection before the run away application does. Does this method work for other global variables…
