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 [...]
Is Synchronous Replication right for your app?
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 [...]
Benchmarking Percona Server TokuDB vs InnoDB
After compiling Percona Server with TokuDB, of course I wanted to compare InnoDB performance vs TokuDB. I have a particular workload I’m interested in testing – it is an insert-intensive workload (which is TokuDB’s strong suit) with some roll-up aggregation, which should produce updates in-place (I will use INSERT .. ON DUPLICATE KEY UPDATE statements [...]
How to diagnose errors in the MySQL error log
I frequently see questions about how to understand the nature of errors in MySQL’s error log. Now, there is a lot of complexity to this — the flowchart would be quite large, as with any nontrivial piece of software. But there is one particular class of errors that is relatively easy to diagnose, if you [...]
Percona Server 5.1.60-13.1
Percona is glad to announce the release of Percona Server 5.1.60-13.1 on December 16, 2011 (Downloads are available from Percona Server 5.1.60-13.1 downloads and from the Percona Software Repositories). Based on MySQL 5.1.60, including all the bug fixes in it, Percona Server 5.1.60-13.1 is now the current stable release in the 5.1 series. All of Percona ‘s software is open-source and free, all the details [...]
Percona Server 5.5.17-22.1 released
Percona is glad to announce the release of Percona Server 5.5.17-22.1 on November 19th, 2011 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.5.17, including all the bug fixes in it, Percona Server 5.5.17-22.1 is now the current stable release in the 5.5 series. All of Percona ‘s software is open-source and free, all the details of the release can [...]
Aligning IO on a hard disk RAID – the Benchmarks
In the first part of this article I have showed how I align IO, now I want to share results of the benchmark that I have been running to see how much benefit can we get from a proper IO alignment on a 4-disk RAID1+0 with 64k stripe element. I haven’t been running any benchmarks [...]
Ultimate MySQL variable and status reference list
I am constantly referring to the amazing MySQL manual, especially the option and variable reference table. But just as frequently, I want to look up blog posts on variables, or look for content in the Percona documentation or forums. So I present to you what is now my newest Firefox toolbar bookmark: an option and [...]
High-Performance Click Analysis with MySQL
We have a lot of customers who do click analysis, site analytics, search engine marketing, online advertising, user behavior analysis, and many similar types of work. The first thing these have in common is that they’re generally some kind of loggable event. The next characteristic of a lot of these systems (real or planned) is [...]
Can you Trust CHECK TABLE ?
Take a look at this:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 | mysql> repair table a3; +---------+--------+----------+----------+ | Table | Op | Msg_type | Msg_text | +---------+--------+----------+----------+ | test.a3 | repair | status | OK | +---------+--------+----------+----------+ 1 row in set (0.10 sec) mysql> select * from a3 order by i; +------------+ | i | +------------+ | 2147483648 | | 11 | | 13 | | 14 | | 2147483647 | +------------+ 5 rows in set (0.00 sec) |
The sort order is obviously wrong while CHECK TABLE is not reporting any error

