An InnoDB table statistics is used for JOIN optimizations and helping the MySQL optimizer choose the appropriate index for a query. If a table’s statistics or index cardinality becomes outdated, you might see queries which previously performed well suddenly show up on slow query log until InnoDB again updates the statistics. But when does InnoDB [...]
Percona Server 5.5.13-20.4 Stable Release
Percona is glad to announce the release of Percona Server 5.5.13-20.4 on July 1st, 2011 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.5.13, Percona Server Percona Server 5.5.13-20.4 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 [...]
Performance Schema tables stats
My previous benchmark on Performance Schema was mainly in memory workload and against single tables. Now after adding multi-tables support to sysbench, it is interesting to see what statistic we can get from workload that produces some disk IO. So let’s run sysbench against 100 tables, each 5000000 rows (~1.2G ) and buffer pool 30G. [...]
How to use tcpdump on very busy hosts
Often I run into problems when trying to use mk-query-digest with tcpdump on “very” busy hosts. You might be thinking, “very busy is a relative and unquantifiable term,” and you’d be right, so I’ll phrase this differently. Let me give a little background to the problem first. Mk-query-digest tries to handle dropped or missing packets [...]
Percona Server and XtraBackup weekly news, March 19th
Here’s what is new in Percona Server and Percona XtraBackup since last week. We are working on compiling and checking download statistics for both pieces of software. The preliminary numbers are far higher than I thought they would be. Both Percona Server and XtraBackup are becoming amazingly popular. I am aware of deployments running into [...]
MySQL on Amazon RDS part 1: insert performance
Amazon’s Relational Database Service (RDS) is a cloud-hosted MySQL solution. I’ve had some clients hitting performance limitations on standard EC2 servers with EBS volumes (see SSD versus EBS death match), and one of them wanted to evaluate RDS as a replacement. It is built on the same technologies, but the hardware and networking are supposed [...]
Modeling MySQL Capacity by Measuring Resource Consumptions
There are many angles you can look at the system to predict in performance, the model baron has published for example is good for measuring scalability of the system as concurrency growths. In many cases however we’re facing a need to answer a question how much load a given system can handle when load is [...]
Percona Server 5.1.55-12.6
Percona Server version 5.1.55-12.6 is now available for download. It is now the current stable release version. Changes Fixed compiler warnings in both the core server and in XtraDB. (Alxey Kopytov, Yasufumi Kinoshita) Bugs Fixed Bug #602047 – The ROWS_READ columns of TABLE_STATISTICS and INDEX_STATISTICS were not properly updated when a query involved index lookups [...]
Percona Server and XtraBackup weekly news, March 5th
What’s new this week in Percona Server:
Estimating Replication Capacity
It is easy for MySQL replication to become bottleneck when Master server is not seriously loaded and the more cores and hard drives the get the larger the difference becomes, as long as replication remains single thread process. At the same time it is a lot easier to optimize your system when your replication runs [...]

