… copy on write filesystem, the snapshots are free, no performance penalty. You can easily run a server with hundreds of snapshots. With LVM… work best with InnoDB, with MyISAM you’ll have to start the snapshot while holding a “flush tables with read lock” and the flush operation will take…
Post: Galera Flow Control in Percona XtraDB Cluster for MySQL
May 2, 2013 By 5 Comments
… applying on any node by simply by running “FLUSH TABLES WITH READ LOCK“, or perhaps by “LOCK TABLE“, in which case flow control will kick in… only lagging nodes will be the slaves with no writes coming from them. However, with multi-node writing, larger queues will make certification more…
Post: Percona XtraBackup 2.1.0 'release candidate' for MySQL available for download
May 7, 2013 By Leave a Comment
….7 in the 2.0 series at the time of writing). New Features: This version of Percona XtraBackup has implemented full… and Importing Tables guide. Bugs Fixed: Percona XtraBackup would crash when preparing the 5.6 backup with partitioned tables. Bug fixed #1169169. Tables that… xtrabackup_56. Bug fixed #1169971. innobackupex would still run with FLUSH TABLES WITH READ LOCK even if xtrabackup would fail when copying logs. Fixed by…
Post: Is Synchronous Replication right for your app?
May 14, 2013 By 18 Comments
…flush_log_at_trx_commit != 1), or work around it with by fsyncing to memory (Battery or capacitor-backed write…makes an achievement, your application updates this table with a statement like this: UPDATE achievements SET …RTT). The other transactions will lock wait until the lock(s) they need are …
Post: MySQL and Percona Server in LinkBench benchmark
May 8, 2013 By 18 Comments
… the social graph OLTP workload. Sources, along with a very nice description of how to …_write_io_threads = 8 innodb_io_capacity = 5000 sync_binlog=0 max_connections=5000 table_open_cache=5000 table…_schema=0 #56only loose-innodb_flush_neighbors=0 loose-metadata_locks_hash_instances=256 innodb_buffer_…
Post: Percona Server 5.5.30-30.2 rerelease fixes non-restart issue
April 24, 2013 By Leave a Comment
… MySQL will now be shipped with the libjemalloc library. Benchmark…TABLE or CREATE TABLE IF NOT EXISTS statements on an existing table could wait on a metadata lock…write-intensive workloads. Bug fixed #1163439 (Alexey Kopytov). Ported back from the upstream MySQL 5.6 the fix for unnecessary log_flush…
Post: Percona Server for MySQL 5.5.30-30.2 now available
April 10, 2013 By 10 Comments
… MySQL will now be shipped with the libjemalloc library. Benchmark…TABLE or CREATE TABLE IF NOT EXISTS statements on an existing table could wait on a metadata lock…write-intensive workloads. Bug fixed #1163439 (Alexey Kopytov). Ported back from the upstream MySQL 5.6 the fix for unnecessary log_flush…
Post: How FLUSH TABLES WITH READ LOCK works with Innodb Tables
March 23, 2012 By 20 Comments
…is no MYISAM like table lock priority problem with pending WRITE query blocks any READ queries to execute on the table. mysql> show…681 | Waiting for table flush | flush tables with read lock | 0 | 0 | 1 | | 10291 | root | localhost | dumptest | Query | 74 | Waiting for global read lock | insert into…
Post: How fast is FLUSH TABLES WITH READ LOCK?
April 24, 2010 By 30 Comments
…Flushing tables” is a misnomer — connection 5 is not flushing tables yet. It’s waiting to get the lock. Flushing tables After the FLUSH TABLES WITH READ LOCK…
Post: SHOW OPEN TABLES - what is in your table cache
December 14, 2008 By 3 Comments
… OPEN TABLES and flush only open tables, when run it again and see how many tables are open and in use and if FLUSH TABLES WITH READ LOCK… is holding lock for this table ? I would much rather see all entries in the table_cache used, not grouped by the table, with thread_id using the table set (0 if table is not in use), lock_type READ/WRITE…
