This blog post is part two of two. Like part one, published Wednesday, this is a cross-post from Groupon’s engineering blog. Thanks again to Kyle Oppenheim at Groupon. And one more reminder that I’ll be at the Percona Live MySQL Conference and Expo next week in Santa Clara, California so look for me there. You [...]
Testing the Micron P320h
April 16, 2013 By 7 Comments
The Micron P320h SSD is an SLC-based PCIe solid-state storage device which claims to provide the highest read throughput of any server-grade SSD, and at Micron’s request, I recently took some time to put the card through its paces, and the numbers are indeed quite impressive. For reference, the benchmarks for this device were performed [...]
Testing the Virident FlashMAX II
March 21, 2013 By 1 Comment
Approximately 11 months ago, Vadim reported some test results from the Virident FlashMax 1400M, an MLC PCIe SSD device. Since that time, Virident has released the FlashMAX II, which promises both increased capacity and increased performance over the previous model. In this post, we present some benchmark results comparing this new model to its predecessor, [...]
Profiling MySQL Memory Usage With Valgrind Massif
January 9, 2013 By 1 Comment
There are times where you need to know exactly how much memory the mysqld server (or any other program) is using, where (i.e. for what function) it was allocated, how it got there (a backtrace, please!), and at what point in time the allocation happened. For example; you may have noticed a sharp memory increase [...]
Percona and the MariaDB Foundation
December 19, 2012 By 3 Comments
There have been several reports (1,2,3) describing Percona’s stance regarding the MariaDB Foundation that are not totally accurate so I though it would be worth it to describe where we stand on this and related matters. First, let me say the creation of theMariaDB Foundation is a good thing for the MariaDB Community and I’m [...]
Percona Server tree with support of Fusion-io atomic writes and DirectFS
September 24, 2012 By Leave a Comment
Not so long ago Fusion-io announced an SDK which provides direct API access to Fusion ioMemory(tm) in addition to providing a native filesystem (directFS) with a goal to avoid overhead from kernel and regular Linux filesystems: ext4 and xfs. This requires a support from application, it should use special calls for IO. With help from [...]
Fusion-io atomic writes and DirectFS
September 20, 2012 By Leave a Comment
Not so far ago Fusion-io announced SDK which provides direct API access to Fusion ioMemory(tm) in addition to providing a native filesystem (directFS) with a goal to avoid overhead from kernel and regular Linux filesystems: ext4 and xfs. Fusion-io will explain these features during our Percona Live New York conference and share performance numbers. It [...]
How to obtain the “LES” (Last Executed Statement) from an Optimized Core Dump?
September 9, 2012 By 9 Comments
Ever ran into a situation where you saw “some important variable you really needed to know about=<optimized out>” while debugging?
Recovery after DROP & CREATE
August 22, 2012 By 1 Comment
In a very popular data loss scenario a table is dropped and empty one is created with the same name. This is because mysqldump in many cases generates the “DROP TABLE” instruction before the “CREATE TABLE”:
1 2 3 4 5 6 7 8 9 10 11 12 | DROP TABLE IF EXISTS `actor`; /*!40101 SET @saved_cs_client = @@character_set_client */; /*!40101 SET character_set_client = utf8 */; CREATE TABLE `actor` ( `actor_id` smallint(5) unsigned NOT NULL AUTO_INCREMENT, `first_name` varchar(45) NOT NULL, `last_name` varchar(45) NOT NULL, `last_update` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP, PRIMARY KEY (`actor_id`), KEY `idx_actor_last_name` (`last_name`) ) ENGINE=InnoDB AUTO_INCREMENT=201 DEFAULT CHARSET=utf8; /*!40101 SET character_set_client = @saved_cs_client */; |
If there were no subsequent CREATE TABLE the recovery would be trivial. Index_id of the PRIMARY index of [...]
Meet Percona at Southeast Linux Fest
June 7, 2012 By Leave a Comment
Percona will be at Southeast Linux Fest tomorrow and Saturday. We’re supporting the event, and we hope to meet you there. If you’ve never been, this is a great regional show that’s grown enormously in the last few years. Peter and I will both be speaking: Peter about optimizing MySQL configuration, and I will talk [...]
