June 20, 2013

Post: Galera Flow Control in Percona XtraDB Cluster for MySQL

May 2, 2013 By 5 Comments

… the receive queue (visible via the wsrep_local_recv_queue global status variable). Donor/Desynced nodes do not apply flow control, though…, and they are all configured via the wsrep_provider_options global variable. gcs.fc_limit This setting controls when flow control engages… happening and where it is coming from There are two global status variables you can check to see what flow control is…

Filed Under: Insight for DBAs, Percona Live, XtraDB Cluster Tagged With: , , ,

Comment: Rotating MySQL slow logs safely

April 18, 2013 By 7 Comments

… to check is if you are using persistent-connections. The global variable long_query_time is checked when the connection is created…_global_control” in 5.5 or “use_global_log_slow_control” in 5.1 in 1 and the server will use the global variable…/doc/percona-server/5.1/diagnostics/slow_extended.html#use_global_log_slow_control PS 5.5 http://www.percona.com…

Filed Under: Insight for DBAs, MySQL Tagged With: , , , , , , ,

Comment: Percona XtraBackup 2.0.7 for MySQL available for download

May 14, 2013 By 1 Comment

…_ch118_3/201305″ innodb_buffer_pool_filename is not a global variable of MySQL 5.5, why this error? thanks!

Filed Under: MySQL Tagged With: , , ,

Post: Is Synchronous Replication right for your app?

May 14, 2013 By 18 Comments

…!).  By enforcing replication to all nodes, we can (simultaneously) establish global ordering for the transaction, so by the time the original… Galera.  We must have group communication to replicate and establish global ordering for every transaction, and the expense of doing that… is retried only the number of times specified by this variable (default is 1 retry).  This means more waiting, and after…

Filed Under: MySQL, Percona Software, XtraDB Cluster Tagged With: , , , , , ,

Post: Can we improve MySQL variable handling ?

February 18, 2012 By 8 Comments

… as technique to detect the value for DEFAULT variables for SESSION variables, yet for some GLOBAL variables setting them back and forth would not… make dealing with MySQL variables in automated way a lot more convenient would be extending INFORMATION_SCHEMA.GLOBAL_VARIABLES Currently as of MySQL 5.5 it contains only variable name and value. Yet I…

Filed Under: MySQL

Post: How to create/restore a slave using GTID replication in MySQL 5.6

February 8, 2013 By 7 Comments

…start the replication: slave1 > show global variables like ‘gtid_executed’; +—————+——-+ | Variable_name | Value | +—————+——-+ | gtid_executed | | +—————+——-+ slave1 > show global variables like ‘gtid_purged’; +—————+——-+ | Variable_name | Value…

Filed Under: MySQL

Comment: Too many connections? No problem!

March 24, 2010 By 28 Comments

… value than you expect your app to reach. Regarding other global variables – it should work but symbols may not match the names… what. To change global wait_timeout and interactive_timeout one would set global_system_variables.net_wait_timeout and global_system_variables.net_interactive_timeout…

Filed Under: Insight for DBAs, MySQL Tagged With: ,

Post: Replication checksums in MySQL 5.6

February 15, 2013 By 3 Comments

… the slave_sql_verify_checksum variable. Let’s first disable them: slave1 [localhost] {msandbox} ((none)) > set global slave_sql_verify_checksum=OFF… for binary log events: master [localhost] {msandbox} ((none)) > show global variables like ‘binlog_checksum’; +—————–+——-+ | Variable_name | Value | +—————–+——-+ | binlog_checksum | CRC32 | +—————–+——-+ We also want…

Filed Under: MySQL Tagged With: , , ,

Post: Infinite Replication Loop

October 10, 2011 By 2 Comments

… flow: [1] When you setup MySQL replication, you define the global variable server_id, this value must be unique for each host… an action you should never perform on a slave. “SET GLOBAL server_id =…” You promote a slave as master to replace… the machines, but the value was not ok in show global variables… it was always 1 !! There was a hidden character in…

Filed Under: MySQL

Post: InnoDB Full-text Search in MySQL 5.6 (part 1)

February 26, 2013 By 1 Comment

… of a table that has a FT index for the global variable innodb_ft_aux_table, we should be able to get…. First, let’s check the stats immediately after setting these variables, and then let’s push some additional data into the… see what happens: mysql> set global innodb_ft_aux_table=’test/dir_test_innodb’; mysql> set global innodb_optimize_fulltext_only=1…

Filed Under: Insight for DBAs, Insight for Developers, MySQL Tagged With: , , , , ,
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