Search Results for: 32 bit

How to avoid hash collisions when using MySQL’s CRC32 function

Percona Toolkit’s  pt-table-checksum performs an online replication consistency check by executing checksum queries on the master, which produces different results on replicas that are inconsistent with the master – and the tool pt-table-sync synchronizes data efficiently between MySQL tables. The tools by default use the CRC32. Other good choices include MD5 and SHA1. If you have installed the FNV_64 user-defined function, pt-table-sync will […]

Percona Server 5.5.34-32.0 is now available

Percona is glad to announce the release of Percona Server 5.5.34-32.0 on October 28th, 2013 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.5.34, including all the bug fixes in it, Percona Server 5.5.34-32.0 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 […]

Percona Server 5.5.32-31.0 now available

Percona is glad to announce the release of Percona Server 5.5.32-31.0 on July 2nd, 2013 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.5.32, including all the bug fixes in it, Percona Server 5.5.32-31.0 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 […]

Testing the Micron P320h

The Micron P320h SSD is an SLC-based PCIe solid-state storage device which claims to provide the highest read throughput of any server-grade SSD, and at Micron’s request, I recently took some time to put the card through its paces, and the numbers are indeed quite impressive. For reference, the benchmarks for this device were performed […]

Intel 320 SSD random write performance

While I like performance provided by PCI-E cards like FusionIO or Virident tachIOn, I am often asked about SATA drives alternatives, as price of PCI-E cards often is barrier, especially for startups. There is wide range of SATA drives on market, and it is hard to pick one, but Intel SSD are probably one of […]

xtrabackup-1.0

Dear Community, As of today release 1.0 is available. In this release there are following changes: Changelog: XtraBackup is ported to Windows. The .MSI package as well as .tar.gz is available for 32 bit platform Be more verbose on reporting scp errors Fixed bugs: Bug #463691 in Percona-XtraBackup: “innobackupex-1.5.1 –help goes to STDERR” Bug #463709 […]

Looking deeper into InnoDB’s problem with many row versions

A few days ago I wrote about MySQL performance implications of InnoDB isolation modes and I touched briefly upon the bizarre performance regression I found with InnoDB handling a large amount of versions for a single row. Today I wanted to look a bit deeper into the problem, which I also filed as a bug. First […]

Hyper-threading – how does it double CPU throughput?

The other day a customer asked me to do capacity planning for their web server farm. I was looking at the CPU graph for one of the web servers that had Hyper-threading switched ON and thought to myself: “This must be quite a misleading graph – it shows 30% CPU usage. It can’t really be […]

Percona Server 5.5.41-37.0 is now available

Percona is glad to announce the release of Percona Server 5.5.41-37.0 on January 9, 2015. Based on MySQL 5.5.41, including all the bug fixes in it, Percona Server 5.5.41-37.0 is now the current stable release in the 5.5 series. Percona Server is open-source and free. Details of the release can be found in the 5.5.41-37.0 […]

How small changes impact complex systems – MySQL example

If you’ve been studying complex systems you know what minor changes might cause consequences of much greater proportions, sometimes causing some effects that are not easily explained at first. I recently ran across a great illustration of such behavior while doing MySQL benchmarks which I thought would be interesting to share. I’m using a very […]