On November 15th at 1PM Eastern / 10 AM Pacific, I will be giving a webinar entitled “The Hazards of Multi-writing in a Dual-Master Setup“. In my experience many people do not understand the difficulty of managing writes to RDBMS datastores in a high availability environment, especially where asynchronous replication is used (which is almost everywhere). [...]
Percona XtraDB Cluster – installation and setup webinar follow up Q&A
October 28, 2012 By 4 Comments
Thanks for all, who attended my webinar, I got many questions and I wanted to take this opportunity to answer them. Q: Even ntp has a delay of 0.3-0.4 between servers does that mean a 0.25 as from logs can be an issue ? A: My demo vms were running for a few hours before [...]
Minimizing Downtime from Lengthy AWS Outages
October 24, 2012 By 6 Comments
Well, it happened again… Another lengthy EBS outage in the US-East region impacted several sites across the net. While failures like this are rare, they can be quite costly and translate into headaches for the operations team when impact production systems for any length of time. At Percona, we routinely help clients architect and deploy [...]
Measuring the amount of writes in InnoDB redo logs
October 8, 2012 By 4 Comments
Choosing a good InnoDB log file size is key to InnoDB write performance. This can be done by measuring the amount of writes in the redo logs. You can find a detailed explanation in this post. To sum up, here are the main points: The redo logs should be large enough to store at most [...]
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 [...]
Automation: A case for synchronous replication
September 19, 2012 By 2 Comments
Just yesterday I wrote about math of automatic failover today I’ll share my thoughts about what makes MySQL failover different from many other components and why asynchronous nature of standard replication solution is causing problems with it. Lets first think about properties of simple components we fail over – web servers, application servers etc. We [...]
How to lag a slave behind to avoid a disaster
September 11, 2012 By 5 Comments
MySQL Replication is useful and easy to setup. It is used for very different purposes. For example: split read and writes run data mining or reporting processes on them disaster recovery Is important to mention that a replication server is not a backup by itself. A mistake on the master, for example a DROP DATABASE [...]
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 [...]
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 [...]
