Search Results for: fix innodb

Innodb vs MySQL index counts

I had a customer recently who a few strange errors in their mysqld.err log:

This customer was running Percona Server 5.1 and they got this error on two tables during a maintenance window when they were adding indexes to the same tables.  We had a suspicion that it had something to do with Fast […]

Looking for InnoDB/XtraDB hacker

We are happy to see that Percona Server/XtraDB and XtraBackup are raising popularity and to keep excitement we want to have more features and more performance fixes! If you are experienced software engineer and feel strong enough to hack InnoDB/XtraDB code we invite you to join our development team to work on the following (but […]

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 […]

Testing the Group Commit Fix

As you may know, Kristian Nielsen made a fix for the Group Commit Problem which we many times wrote about. The fix came into MariaDB 5.3 and Mark Callaghan tested it recently . We ported this patch to Percona Server (it is not in the main branch yet), and here are the results of my […]

Innodb Caching (part 2)

Few weeks ago I wrote about Innodb Caching with main idea you might need more cache when you think you are because Innodb caches data in pages, not rows, and so the whole page needs to be in memory even if you need only one row from it. I have created the simple benchmark which […]

InnoDB Flushing: Theory and solutions

I mentioned problems with InnoDB flushing in a previous post. Before getting to ideas on a solution, let’s define some terms and take a look into theory. The two most important parameters for InnoDB performance are innodb_buffer_pool_size and innodb_log_file_size. InnoDB works with data in memory, and all changes to data are performed in memory. In […]

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 […]

Lost innodb tables, xfs and binary grep

Before I start a story about the data recovery case I worked on yesterday, here’s a quick tip – having a database backup does not mean you can restore from it. Always verify your backup can be used to restore the database! If not automatically, do this manually, at least once a month. No, seriously […]