As part of Percona Remote DBA for MySQL service we recognize that reliable backups are one of the most important things we can bring to the table. In my experience handling emergencies, the single worst thing that can happen is finding out you don’t have backups available when some sort of data loss or catastrophic [...]
MySQL 5.6 vs MySQL 5.5 and the Star Schema Benchmark
March 11, 2013 By 7 Comments
So far most of the benchmarks posted about MySQL 5.6 use the sysbench OLTP workload. I wanted to test a set of queries which, unlike sysbench, utilize joins. I also wanted an easily reproducible set of data which is more rich than the simple sysbench table. The Star Schema Benchmark (SSB) seems ideal for this. [...]
How does MySQL Replication really work?
January 9, 2013 By 9 Comments
While we do have many blog posts on replication on our blog, such as on replication being single-threaded, on semi-synchronous replication or on estimating replication capacity, I don’t think we have one that covers the very basics of how MySQL replication really works on the high level. Or it’s been so long ago I can’t [...]
Is there room for more MySQL IO Optimization?
January 3, 2013 By 11 Comments
I prefer to run MySQL with innodb_flush_method=O_DIRECT in most cases – it makes sure there is no overhead of double buffering and I can save the limited amount of file system cache I would normally have on database server for those things which need to be cached — system files, binary log, FRM files, MySQL [...]
L2 cache for MySQL
October 25, 2012 By 13 Comments
The idea to use SSD/Flash as a cache is not new, and there are different solutions for this, both OpenSource like L2ARC for ZFS and Flashcache from Facebook, and proprietary, like directCache from Fusion-io. They all however have some limitations, that’s why I am considering to have L2 cache on a database level, as an [...]
The Math of Automated Failover
September 18, 2012 By 9 Comments
There are number of people recently blogging about MySQL automated failover, based on production incident which GitHub disclosed. Here is my take on it. When we look at systems providing high availability we can identify 2 cases of system breaking down. First is when the system itself has a bug or limitations which does not [...]
Intel SSD 910 vs HDD RAID in tpcc-mysql benchmark
September 11, 2012 By 6 Comments
I continue my benchmarks of Intel SSD 910, previous time I compared it with Fusion-io ioDrive http://www.mysqlperformanceblog.com/2012/09/07/intel-ssd-910-in-tpcc-mysql-benchmark/. Now I want to test this card against RAID over spinning disks.
Testing Intel® SSD 910
September 4, 2012 By 2 Comments
Intel came on PCI-e SSD market with their Intel SSD 910 card. With a slogan “The ultimate data center SSD” I assume Intel targets rather a server grade hardware, not consumer level. I’ve got one of this card into our lab. I should say it is very price competitive, comparing with other enterprise level PCIe [...]
ALTER TABLE: Creating Index by Sort and Buffer Pool Size
June 27, 2012 By 4 Comments
Today I was looking at the ALTER TABLE performance with fast index creation and without it with different buffer pool sizes. Results are pretty interesting. I used modified Sysbench table for these tests because original table as initially created only has index on column K which initially contains only zeros, which means index is very [...]
DROP TABLE and stalls: Lazy Drop Table in Percona Server and the new fixes in MySQL
June 22, 2012 By 33 Comments
Suppose you have turned on innodb_file_per_table (which means that each table has its own tablespace), and you have to drop tables in a background every hour or every day. If its once every day then you can probably schedule the table dropping process to run during off-peak hours. But I have seen cases where the [...]
