April 20, 2014

How to obtain the “LES” (Last Executed Statement) from an Optimized Core Dump?

Ever ran into a situation where you saw “some important variable you really needed to know about=<optimized out>” while debugging?

Getting MySQL Core file on Linux

Core file can be quite helpful to troubleshoot MySQL Crashes yet it is not always easy to get, especially with recent Linux distributions which have security features to prevent core files to be dumped by setuid processes (and MySQL Server is most commonly ran changing user from “root” to “mysql”). Before you embark on enabling […]

Modeling InnoDB Scalability on Multi-Core Servers

Mat Keep’s blog post on InnoDB-vs-MyISAM benchmarks that Oracle recently published prompted me to do some mathematical modeling of InnoDB’s scalability as the number of cores in the server increases. Vadim runs lots of benchmarks that measure what happens under increasing concurrency while holding the hardware constant, but not as many with varying numbers of […]

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 scalability on multi-cores server

We now have hardware in our test lab that represents the next generation of commodity servers for databases. It’s a Cisco UCS C250 server, powered by two Intel Westmere CPUs (X5670 @ 2.93GHz). Each CPU has 6 cores and 12 threads. The most amazing part is the amount of memory. It has 384GB of RAM, which is […]

Performance improvements in Percona 5.0.83 and XtraDB

There was small delay in our releases, part of this time we worked on features I mentioned before: – Moving InnoDB tables between servers – Improve InnoDB recovery time and rest time we played with performance trying to align XtraDB performance with MySQL 5.4 ® and also port all performance fixes to 5.0 tree. So […]

What time 18446744073709550.000 means

Sometimes when you do profiling you can see number like this in timestamps. Periodically in our patches there was Query_time: 18446744073709550.000 in slow.log file (well, it was fixed recently, but still appears in other places). I faced this problem several years ago when only 2-core AMD Opteron systems appeared and I noticed sysbench getting crazy […]

XtraDB/InnoDB CPU bound benchmarks on 24cores server

One of our customers gave me a chance to run some benchmarks on 24-core (intel cpu based) server, and I could not miss it and ran few CPU-bound tasks there. The goal of benchmarks was investigation of InnoDB-plugin and XtraDB scalability in CPU-bound load.

128GB or RAM finally got cheap

I did not usually go to “Elite” servers on Dell web site but looking at customers system today I went to check Dell Poweredge R900. This monster takes up to 4 Quad Core CPUs and has 32 memory slots, which allows to get 128GB of memory with 4GB of memory chips. This means upgrade to […]

Sphinx 0.9.8 is released just in time for OSCON 2008

As you probably already seen in a post by Baron, Sphinx Release 0.9.8 is finally out, just in time for OSCON 2008. Even though it is “minor release” if you look at the number, it is major release in practice (and you can view snapshots as minor releases). The changes since 0.9.7 are dramatic with […]