… of other MySQL and OS-level status variables that you might want to keep an eye on to prevent a problem before… the MySQL world, except maybe MyISAM files on top of a clustered filesystem with an external lock manager. You might say that MySQL…: Incorrect information in file: ‘./mysql/servers.frm’ ERROR: 1033 Incorrect information in file: ‘./mysql/servers.frm’ Running mysql_install_db under strace, I…
Post: Webinar: MySQL 5.6 Performance Schema
May 13, 2013 By 5 Comments
….m. Pacific, I’ll be leading a Webinar titled, “Using MySQL 5.6 Performance Schema to Troubleshoot Typical Workload Bottlenecks.” In… Schema, focusing on new features that have been added in MySQL 5.6, go over the configuration and spend most time… IO Problems with excessive temporary tables and external sorts Excessive internal mutex contention Slow queries due to waits on InnoDB locks and…
Post: Percona Server for MySQL 5.5.30-30.2 now available
April 10, 2013 By 10 Comments
…an existing table could wait on a metadata lock instead of failing or returning immediately if …in read_view_open_now() which is another problem originally reported as upstream bug #49169. This also… (Alexey Bychko). Percona Server for MySQL was missing help texts in the MySQL client because the help …
Post: MySQL 5.6 Compatible Percona Toolkit 2.2 Released
March 25, 2013 By 2 Comments
…_lock_wait_timeout because that now conflicts, or is at least confused with, lock_wait_timeout (introduced in MySQL 5.5) for metadata locks…, and MariaDB Galera Cluster), upgrades are fashionable, so to speak. Problem is: “original” pt-upgrade was too noisy and too complex… two versions of the DBD::mysql Perl module that have problems. And there are certain versions of MySQL that have critical bugs. Version…
Post: Is Synchronous Replication right for your app?
May 14, 2013 By 18 Comments
… the client is forced to correct the problem before it can commit. It is NOT … standard MySQL replication from this instance, since MySQL replication is asynchronous. What about semi-sync MySQL replication? … 1 RTT). The other transactions will lock wait until the lock(s) they need are available. …
Post: Open Source, the MySQL market (and TokuDB in particular)
May 10, 2013 By 13 Comments
… the following benefits to your customers: No vendor lock-in. And this is significant. Customers often … “In principle, anyone who has an interest in MySQL and MariaDB surviving should contact the MariaDB foundation… as many as we originally hoped for .. One problem we had was that we needed to prove…
Post: trx descriptors: MySQL performance improvements in Percona Server 5.5.30-30.2
April 12, 2013 By 3 Comments
…, even within the same transaction. Why is that a major problem for MySQL scalability? The scan is performed under kernel_mutex (or… following kinds of transactions: MySQL transactions started with START TRANSACTION READ ONLY MySQL transactions created by a non-locking SELECT statement in the…
Post: Percona Server 5.5.30-30.2 rerelease fixes non-restart issue
April 24, 2013 By Leave a Comment
… its state before updating. This caused some problems for some users, especially if automatic upgrading … existing table could wait on a metadata lock instead of failing or returning immediately if …(Alexey Bychko). Percona Server for MySQL was missing help texts in the MySQL client because the help …
Post: How FLUSH TABLES WITH READ LOCK works with Innodb Tables
March 23, 2012 By 20 Comments
…. Lets look at what the problem is. As of MySQL 5.5 FLUSH TABLES WITH READ LOCK does not work as optimally as… no MYISAM like table lock priority problem with pending WRITE query blocks any READ queries to execute on the table. mysql> show processlist… see this problem fixed. There is no reason (other than code design) for read lock to wait for other read lock in order…
Post: Scaling problems still exist in MySQL 5.5 and Percona Server 5.5
May 20, 2011 By 11 Comments
MySQL 5.5 and Percona Server 5.5 do not solve all scalability problems even for read only workloads. Workloads which got… is almost perfect scalability. So there are workloads where the problem is solved and when there are where a lot of…_event_wait_low,sync_array_wait_event,rw_lock_s_lock_spin,pfs_rw_lock_s_lock_fu nc,btr_search_build_page_hash…
