August 21, 2014

Understand InnoDB spin waits, win a Percona Live ticket

It’s Friday again (so soon!) and time for our TGIF contest, to give away a free ticket to Percona Live London. Before we do that, though, just what in the world does this output from SHOW INNODB STATUS mean?

To understand this text, you have to understand how InnoDB handles mutexes. It tries a […]

How Innodb Contention may manifest itself

Even though multiple fixes have been implemented in Percona Server and MySQL 5.5, there are still workloads in which case mutex (or rw-lock) contention is a performance limiting factor, helped by ever growing number of cores available in the systems. It is interesting though the contention may manifest itself in the different form from the […]

InnoDB compression woes

InnoDB compression is getting some traction, and I see quite contradictory opinions. Someone has successful deployments in productions, and someone says that compression in current implementation is useless. To get some initial impression about performance I decided to run some sysbench with multi-tables benchmarks. I actually was preparing to do complex research, but even first […]

High Rate insertion with MySQL and Innodb

I again work with the system which needs high insertion rate for data which generally fits in memory. Last time I worked with similar system it used MyISAM and the system was built using multiple tables. Using multiple key caches was the good solution at that time and we could get over 200K of inserts/sec. […]

Analyzing the distribution of InnoDB log file writes

I recently did a quick analysis of the distribution of writes to InnoDB’s log files. On a high-traffic commodity MySQL server running Percona XtraDB for a gaming workload (mostly inserts to the “moves” table), I used strace to gather statistics about how the log file writes are distributed in terms of write size. InnoDB writes […]

Index lock and adaptive search – next two biggest InnoDB problems

Running many benchmarks on fast storage (FusionIO, SSDs) and multi-cores CPUs system I constantly face two contention problems. So I suspect it’s going to be next biggest issues to make InnoDB scaling on high-end system. This is also reason why in benchmarks I posted previously CPU usage is only about 50%, leaving other 50% in […]

InnoDB, InnoDB-plugin vs XtraDB on fast storage

To continue fun with FusionIO cards, I wanted to check how MySQL / InnoDB performs here. For benchmark I took MySQL 5.1.42 with built-in InnoDB, InnoDB-plugin 1.0.6, and XtraDB 1.0.6-9 ( InnoDB with Percona patches). As benchmark engine I used tpcc-mysql with 1000 warehouses ( which gives around 90GB of data + indexes) on my […]

What to do with MySQL Full Text Search while migrating to Innodb ?

It is rather typical for systems to start as MyISAM but as system growths to move to Innodb. The reason of the move could be just desire for better data consistency guaranty or being bitten repairing multiple GB MyISAM table few times, though Table Locks is probably the most important issue – with modern multi […]

Innodb plugin 1.0.4 released – great job Innobase

As you might have seen Innodb Plugin 1.0.4 was released today. I am very excited to see this release which is released exactly 5 months after release of Innodb Plugin 1.0.3 (I honestly expected to see Innodb Plugin 1.0.4 to be released by MySQL Conference and Expo in April). This also is still “early adopter” […]

The perils of InnoDB with Debian and startup scripts

Are you running MySQL on Debian or Ubuntu with InnoDB? You might want to disable /etc/mysql/debian-start. When you run /etc/init.d/mysql start it runs this script, which runs mysqlcheck, which can destroy performance. It can happen on a server with MyISAM tables, if there are enough tables, but it is far worse on InnoDB. There are […]