Search Results for: set open files limit

Backup and restore of MySQL to OpenStack Swift

MySQL database usage is popular in OpenStack. Core OpenStack services for Compute (Nova), Storage (Cinder), Neutron (Networking), Image (Glance) and Identity (Keystone) all use MySQL database. MySQL – as the world’s most popular database, runs inside OpenStack Virtual Machines and serves as database backend to OpenStack cloud based applications. The MySQL instances can be configured […]

Rackspace doubling-down on open-source databases, Percona Server

Founded in 1998, Rackspace has evolved over the years to address the way customers are using data – and more specifically, databases. The San Antonio-based company is fueling the adoption of cloud computing among organizations large and small. Today Rackspace is doubling down on open source database technologies. Why? Because that’s where the industry is […]

Can’t Create Thread: Errno 11 (A Tale of Two Ulimits)

Recently some of my fellow Perconians and I have noticed a bit of an uptick in customer cases featuring the following error message:

The canonical solution to this issue, if you do a bit of Googling, is to increase the number of processes / threads available to the MySQL user, typically by adding a […]

MySQL opening .frm even when table is in table definition cache

or… “the case of Stewart recognizing parameters to the read() system call in strace output”. Last week, a colleague asked a question: I have an instance of MySQL with 100 tables and the table_definition_cache set to 1000. My understanding of this is that MySQL won’t revert to opening the FRM files to read the table […]

How innodb_open_files affects performance

Recently I looked at table_cache sizing which showed larger table cache does not always provides the best performance. So I decided to look at yet another similar variable – innodb_open_files which defines how many files Innodb will keep open while working in innodb_file_per_table mode. Unlike MyISAM Innodb does not have to keep open file descriptor […]

MySQL 5.6 Transportable Tablespaces best practices

In MySQL 5.6 Oracle introduced a Transportable Tablespace feature (copying tablespaces to another server) and Percona Server adopted it for partial backups which means you can now take individual database or table backups and your destination server can be a vanilla MySQL server. Moreover, since Percona Server 5.6, innodb_import_table_from_xtrabackup is obsolete as Percona Server also […]

MySQL’s INNODB_METRICS table: How much is the overhead?

Starting with MySQL 5.6 there is an INNODB_METRICS table available in INFORMATION_SCHEMA which contains some additional information than provided in the SHOW GLOBAL STATUS output – yet might be more lightweight than PERFORMANCE_SCHEMA. Too bad INNODB_METRICS was designed during the Oracle-Sun split under MySQL leadership and so it covers only InnoDB counters. I think this […]

Percona XtraBackup 2.2.5 now available (free MySQL hot backup software)

Percona is glad to announce the release of Percona XtraBackup 2.2.5 on October 2, 2014. Downloads are available from our download site here and Percona Software Repositories. Percona XtraBackup enables MySQL backups without blocking user queries, making it ideal for companies with large data sets and mission-critical applications that cannot tolerate long periods of downtime. […]