Search Results for: how to change time for flush memory to disk

Using Cgroups to Limit MySQL and MongoDB memory usage

Quite often, especially for benchmarks, I am trying to limit available memory for a database server (usually for MySQL, but recently for MongoDB also). This is usually needed to test database performance in scenarios with different memory limits. I have physical servers with the usually high amount of memory (128GB or more), but I am […]

pt-online-schema-change and binlog_format

Statement-based or row-based, or mixed?  We’ve all seen this discussed at length so I’m not trying to rehash tired arguments.  At a high level, the difference is simple: Statement based replication (SBR) replicates the SQL statements to the slave to be replayed Row based replication (RBR) replicates the actual rows changed to the slave to […]

Adaptive flushing in MySQL 5.6

As you may know, flushing in MySQL is an area of my interest, I wrote about it several times, i.e. https://www.percona.com/blog/2011/09/18/disaster-mysql-5-5-flushing/ https://www.percona.com/blog/2011/03/31/innodb-flushing-a-lot-of-memory-and-slow-disk/ https://www.percona.com/blog/2011/01/03/mysql-5-5-8-in-search-of-stability/ In MySQL 5.6 there was implemented a new flushing logic, so I decided to check what do we have now.

Disaster: MySQL 5.5 Flushing

We raised topic of problems with flushing in InnoDB several times, some links: InnoDB Flushing theory and solutions MySQL 5.5.8 in search of stability This was not often recurring problem so far, however in my recent experiments, I observe it in very simple sysbench workload on hardware which can be considered as typical nowadays.

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 […]

Adjusting Innodb for Memory resident workload

As larger and larger amount of memory become common (512GB is something you can fit into relatively commodity server this day) many customers select to build their application so all or most of their database (frequently Innodb) fits into memory. If all tables fit in Innodb buffer pool the performance for reads will be quite […]

When is it a time to upgrade memory ?

Quite commonly I get a question similar to this – “My Innodb Buffer Pool is already 90% full, should I be thinking about upgrading memory already?” This is a wrong way to put the question. Unless you have very small database (read as database which is less than innodb_buffer_pool_size) You will have all buffer pool […]

InnoDB crash recovery speed in MySQL 5.6

It has been a while since I have looked at InnoDB crash recovery. A lot has change in the last few years – we have serious crash recovery performance improvements in MySQL 5.5 and MySQL 5.6, we have solid state drives raising as typical high performance IO subsystem and we also have the ability to […]