This is the second part in a two-part series comparing Virident’s vCache to FlashCache. The first part was focused on usability and feature comparison; in this post, we’ll look at some sysbench test results. Disclosure: The research and testing conducted for this post were sponsored by Virident. First, some background information. All tests were conducted [...]
Virident vCache vs. FlashCache: Part 1
May 16, 2013 By 3 Comments
(This is part one of a two part series) Over the past few weeks I have been looking at a preview release of Virident’s vCache software, which is a kernel module and set of utilities designed to provide functionality similar to that of FlashCache. In particular, Virident engaged Percona to do a usability and feature-set [...]
Is Synchronous Replication right for your app?
May 14, 2013 By 17 Comments
I talk with lot of people who are really interested in Percona XtraDB Cluster (PXC) and mostly they are interested in PXC as a high-availability solution. But, what they tend not to think too much about is if moving from async to synchronous replication is right for their application or not. Facts about Galera replication [...]
Galera Flow Control in Percona XtraDB Cluster for MySQL
May 2, 2013 By 5 Comments
Last week at Percona Live, I delivered a six-hour tutorial about Percona XtraDB Cluster (PXC) for MySQL. I actually had more material than I covered (by design), but one thing I regret we didn’t cover was Flow control. So, I thought I’d write a post covering flow control because it is important to understand. What [...]
Percona Server 5.5.30-30.2 rerelease fixes non-restart issue
April 24, 2013 By Leave a Comment
In our last 5.5 series release of Percona Server, we included a regression in the RPM packaging that prevented the server from restarting following an upgrade — instead, the server would remain stopped after the upgrade was completed regardless of its state before updating. This caused some problems for some users, especially if automatic upgrading was configured [...]
The write cache: Swap insanity tome III
April 19, 2013 By 5 Comments
Swapping has always been something bad for MySQL performance but it is even more important for HA systems. It is so important to avoid swapping with HA that NDB cluster basically forbids calling malloc after the startup phase and hence its rather complex configuration. Probably most readers of this blog know (or should know) about [...]
Percona XtraDB Cluster 5.5.30-23.7.4 for MySQL now available
April 17, 2013 By 2 Comments
Percona is glad to announce the release of Percona XtraDB Cluster 5.5.30-23.7.4 for MySQL on April 17, 2013. Binaries are available from the downloads area or from our software repositories. New Features: Percona XtraDB Cluster has implemented initial implementation of weighted quorum. Weight for node can be assigned via pc.weight option in the wsrep_provider_options variable. [...]
trx descriptors: MySQL performance improvements in Percona Server 5.5.30-30.2
April 12, 2013 By 2 Comments
One major problem in terms of MySQL performance that still stands in the way of InnoDB scalability is the trx_list scan on consistent read view creation. It was originally reported as a part of MySQL bug #49169 and can be described as follows. Whenever a connection wants to create a consistent read, it has to [...]
10 years of MySQL User Conferences
April 11, 2013 By 6 Comments
In preparing for this month’s Percona Live MySQL Conference and Expo, I’ve been reminiscing about the annual MySQL User Conference’s history – the 9 times it previously took place in its various reincarnations – and there are a lot of good things, fun things to remember. 2003 was the year that marked the first MySQL user conference [...]
MySQL 5.6.10 Optimizer Limitations: Index Condition Pushdown
March 14, 2013 By 2 Comments
While preparing the webinar I will deliver this Friday, I ran into a quite interesting (although not very impacting) optimizer issue: a “SELECT *” taking half the time to execute than the same “SELECT one_indexed_column” query in MySQL 5.6.10. This turned into a really nice exercise for checking the performance and inner workings of one [...]
