Problem with kernel_mutex in MySQL 5.1 and MySQL 5.5 is known: Bug report. In fact in MySQL 5.6 there are some fixes that suppose to provide a solution, but MySQL 5.6 yet has long way ahead before production, and it is also not clear if the problem is really fixed. Meantime the problem with kernel_mutex [...]
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 [...]
Aligning IO on a hard disk RAID – the Theory
Now that flash storage is becoming more popular, IO alignment question keeps popping up more often than it used to when all we had were rotating hard disk drives. I think the reason is very simple – when systems only had one bearing hard disk drive (HDD) as in RAID1 or one disk drive at [...]
Shard-Query EC2 images available
Infobright and InnoDB AMI images are now available There are now demonstration AMI images for Shard-Query. Each image comes pre-loaded with the data used in the previous Shard-Query blog post. The data in the each image is split into 20 “shards”. This blog post will refer to an EC2 instances as a node from here [...]
How InnoDB handles REDO logging
Xaprb (Baron) recently blogged about how InnoDB performs a checkpoint , I thought it might be useful to explain another important mechanism that affects both response time and throughput – The transaction log.
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 [...]
Effect from innodb log block size 4096 bytes
In my post MySQL 5.5.8 and Percona Server: being adaptive I mentioned that I used innodb-log-block-size=4096 in Percona Server to get better throughput, but later Dimitri in his article MySQL Performance: Analyzing Percona’s TPCC-like Workload on MySQL 5.5 sounded doubt that it really makes sense. Here us quote from his article: “Question: what is a [...]
MySQL 5.5.8 and Percona Server on Fast Flash card (Virident tachIOn)
This is to follow up on my previous post and show the results for MySQL 5.5.8 and Percona Server on the fastest hardware I have in our lab:Â a Cisco UCS C250 server with 384GB of RAM, powered by a Virident tachIOn 400GB SLC card. To see different I/O patterns, I used different innodb_buffer_pool_size settings: 13G, [...]
MySQL 5.5.8 and Percona Server: being adaptive
As we can see, MySQL 5.5.8 comes with great improvements and scalability fixes. Adding up all the new features, you have a great release. However, there is one area I want to touch on in this post. At Percona, we consider it important not only to have the best peak performance, but also stable and predictable performance. I refer you [...]
Percona Server 5.1.49-rel11.3
Dear Community, Percona Server version 5.1.49-rel11.3 is now available for download. The changes in this release include: New features Percona Server 5.1.49-rel11.3 is based on MySQL 5.1.49. A new variable was introduced: innodb_use_sys_stats_table. If ON, the table’s statistics are stored statically in the internal table SYS_STATS. The table is populated with the ANALYZE TABLE command. [...]

