One of the very frequent cases with performance problems with MySQL is what they happen every so often or certain times. … you need to know it is not MySQL problem, might be even not problem with your MySQL configuration, queries and hardware, even though fixing… will suffer. So what you can do to prevent this problem from happening ? The answer is easy. Throttle the side load…
Post: Benchmarking single-row insert performance on Amazon EC2
May 16, 2012 By 11 Comments
… software RAID 10. Now let’s come to the MySQL configuration. MySQL Configuration I used Percona Server 5.5.22-55 for… read performance to improve, but they have an impact on the write performance. Well most of the apps rely on read performance and… write performance is using partitioning to reduce the size of the B+tree, having multiple buffer pool instances to reduce contention problems…
Comment: Benchmarking single-row insert performance on Amazon EC2
May 16, 2012 By 11 Comments
… the performance you are seeing. But first I’d like to note that this experiment isn’t really running the iiBench problem…’t graph the performance on the first 100M rows). The minimum performance troughs occur just as the partition switches. So performance gets worse….launchpad.net/~mdcallag/mysql-patch/mytools/annotate/head%3A/bench/ibench/iibench.py) is that it measures query performance too, so if…
Post: Joining many tables in MySQL - optimizer_search_depth
April 20, 2012 By 6 Comments
… itself was taking same 5 seconds, which points to problem with optimizer performance. Note though if you have subqueries these might need… phase yet making it unusable to check the optimizer performance. Solution for this problem was to use set optimizer_search_depth=0… further I found the following explanation from Timour Katchaounov in MySQL mailing list archives I have some recollection that there were…
Post: Introducing the pmp-check-mysql-status Nagios Plugin
March 29, 2012 By Leave a Comment
… research to be frequent, severe, or subtle causes of problems in MySQL systems. They are intentionally not generic because I wanted to… I believe it should help avoid some of the common problems such as spammy alerts. There is one “generic, flexible” plugin… counters and variables. This is the pmp-check-mysql-status plugin, which can perform computations on status variables. By default, I recommend…
Post: Best kept MySQLDump Secret
March 23, 2012 By 11 Comments
… ? The problem comes from the fact how MySQL‘s Transactions work with DDL, In particular ALTER TABLE. When ALTER TABLE is Performed in… pretty edge case scenario neither the less it can be problem for some workloads which run ALTER TABLE regularly during normal… potential cause for it. What are potential solutions for this problem ? you can use mysqldump –lock-all-tables instead which does…
Post: InnoDB's gap locks
March 27, 2012 By 15 Comments
…in your transactions affecting the concurrency and the performance you can disable them in two different ways:…(non repeatable reads) so in order to prevent problems with the replication you should change the ….1/en/innodb-locks-set.html. Conclusion MySQL uses REPEATABLE READ as the default isolation …
Post: ext4 vs xfs on SSD
March 15, 2012 By 23 Comments
… our recommendation is xfs, and it comes to known problem in ext3, where IO gets serialized per i_node… MiB/sec xfs 4 threads: 97 MiB/sec Dropping performance in case with 4 threads for ext4 is a…more point to consider. Starting the MySQL 5.1 + InnoDB-plugin and later MySQL 5.5 (or equally Percona …
Post: Testing Samsung SSD SATA 256GB 830 - not all SSD created equal
April 25, 2012 By 10 Comments
… every 10 sec to see how stable the performance is, and it really helps to observe some …seems that InnoDB is not alone with its flashing problems. You can see there periodical stalls in throughput (… interested more in SSD and MySQL questions – I will be giving a webinary “MySQL and SSD” on May-…
Comment: MariaDB 5.3 is released as GA!
March 7, 2012 By 17 Comments
… is closing MySQL source code.) Personally I don’t see the problem distros have with the MySQL model. Contrary to common belief MySQL maintenance… patch security issues whereas MySQL also fixes non-security bugs like server crash, wrong result or just performance regressions. From my point…
