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 [...]
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 [...]
Realtime stats to pay attention to in Percona XtraDB Cluster and Galera
November 26, 2012 By 4 Comments
I learn more and more about Galera every day. As I learn more, I try to keep my myq_gadgets toolkit up to date with what I consider is important to keep any eye on on a PXC node. In that spirit, I just today pushed some changes to the ‘wsrep’ report, and I thought I’d go over [...]
How Much memory do you use to run MySQL
November 2, 2012 By 8 Comments
We have seen number of issues with MySQL Server related to amount of memory you have in the system – these range from problems with large size Query Cache to bad drop table performance with large Innodb Buffer Pool size. As such I wonder how much memory do we really use to run MySQL Server [...]
Knowing what pt-online-schema-change will do
November 1, 2012 By 1 Comment
pt-online-schema-change is simple to use, but internally it is complex. Baron’s webinar about pt-online-schema-change hinted at several of the tool’s complexities. Consequently, users often want to know before making changes what pt-online-schema-change will do when it runs. The tool has two options to help answer this question: –dry-run and –print. When ran with –dry-run and –print, pt-online-schema-change changes nothing [...]
Tools and Techniques for Index Design Webinar Questions Followup
October 4, 2012 By 5 Comments
I presented a webinar this week to give an overview of Tools and Techniques for Index Design. Even if you missed the webinar, you can register for it, and you’ll be emailed a link to the recording. I’d like to invite folks who are interested in tools for query optimization to attend the new Percona [...]
SQL Injection Questions Followup
July 26, 2012 By 2 Comments
I presented a webinar today about SQL Injection, to try to clear up some of the misconceptions that many other blogs and articles have about this security risk. You can register for the webinar even now that I’ve presented it, and you’ll be emailed a link to the recording, which will be available soon. During [...]
Impact of memory allocators on MySQL performance
July 5, 2012 By 11 Comments
MySQL server intensively uses dynamic memory allocation so a good choice of memory allocator is quite important for the proper utilization of CPU/RAM resources. Efficient memory allocator should help to improve scalability, increase throughput and keep memory footprint under the control. In this post I’m going to check impact of several memory allocators on the [...]
Comparing Percona XtraDB Cluster with Semi-Sync replication Cross-WAN
June 14, 2012 By 7 Comments
I have a customer who is considering Percona XtraDB Cluster (PXC) in a two colo WAN environment. They wanted me to do a test comparing PXC against semi-synchronous replication to see how they stack up against each other. Test Environment The test environment included AWS EC2 nodes in US-East and US-West (Oregon). The ping RTT latency [...]
A case for MariaDB’s Hash Joins
May 31, 2012 By Leave a Comment
MariaDB 5.3/5.5 has introduced a new join type “Hash Joins” which is an implementation of a Classic Block-based Hash Join Algorithm. In this post we will see what the Hash Join is, how it works and for what types of queries would it be the right choice. I will show the results of executing benchmarks [...]
