August 1, 2014

InnoDB memory allocation, ulimit, and OpenSUSE

I recently encountered an interesting case. A customer reported that mysqld crashed on start on OpenSUSE 11.2 kernel 2.6.31.12-0.2-desktop x86_64   with 96 GB RAM when the innodb_buffer_pool_size was set to anything more than 62 GB. I decided to try it with 76 GB. The error message was an assert due to a failed malloc() […]

Innodb redo log archiving

Percona Server 5.6.11-60.3 introduces a new “log archiving” feature. Percona XtraBackup 2.1.5 supports “apply archived logs.” What does it mean and how it can be used? Percona products propose three kinds of incremental backups. The first is full scan of data files and comparison the data with backup data to find some delta. This approach […]

MySQL server memory usage troubleshooting tips

There are many blog posts already written on topics related to “MySQL server memory usage,” but nevertheless there are some who still get confused when troubleshooting issues associated with memory usage for MySQL. As a Percona support engineer, I’m seeing many issues regularly related to heavy server loads – OR OOM killer got invoked and […]

InnoDB performance optimization basics (redux)

I recently stumbled upon a post that Peter Zaitsev published back in 2007 titled “Innodb Performance Optimization Basics.” It’s a great post and reading it inspired me to examine what’s changed in the nearly six years that have followed in terms of MySQL, Percona Server – as well as in all of the other now-available […]

Limited disk space? Compact backups with Percona Xtrabackup 2.1

One very interesting feature, “Compact Backup,” is introduced in Percona XtraBackup 2.1. You can run “compact backups” with the  –compact option, which is very useful for those who have limited disk space to keep the MySQL database backup. Now let’s first understand how it works. When we are using –compact option with Innobackupex, it will omit the […]

MySQL and the SSB – Part 2 – MyISAM vs InnoDB low concurrency

This blog post is part two in what is now a continuing series on the Star Schema Benchmark. In my previous blog post I compared MySQL 5.5.30 to MySQL 5.6.10, both with default settings using only the InnoDB storage engine.  In my testing I discovered that innodb_old_blocks_time had an effect on performance of the benchmark.  There was […]

Memory allocators: MySQL performance improvements in Percona Server 5.5.30-30.2

In addition to the problem with trx_list scan we discussed in Friday’s post, there is another issue in InnoDB transaction processing that notably affects MySQL performance – for every transaction InnoDB creates a read view and allocates memory for this structure from heap. The problem is that the heap for that allocation is destroyed on […]

MySQL 5.6.10 Optimizer Limitations: Index Condition Pushdown

While preparing the webinar I will deliver this Friday, I ran into a quite interesting (although not very impacting) optimizer issue: a “SELECT *” taking half the time to execute than the same “SELECT one_indexed_column” query in MySQL 5.6.10. This turned into a really nice exercise for checking the performance and inner workings of one […]

InnoDB Full-text Search in MySQL 5.6: Part 2, The Queries!

This is part 2 in a 3 part series. In part 1, we took a quick look at some initial configuration of InnoDB full-text search and discovered a little bit of quirky behavior; here, we are going to run some queries and compare the result sets. Our hope is that the one of two things […]