…MySQL replication from this instance, since MySQL replication is asynchronous. What about semi-sync MySQL… waiting, you could simply send all your writes to one …to retry after the database state changes. retry deadlocks Now we… Choosing a system to replicate your data to a distributed system requires …
Post: Implications of Metadata Locking Changes in MySQL 5.5
February 1, 2013 By 9 Comments
…Data Locking behavior prior to MySQL 5.5.3 Metadata Locking behavior prior to MySQL 5.5.3 Prior to MySQL….000006 | | executing | 0.000001 | | Sorting result | 0.000002 | | Sending data | 0.000040 | | end | 0.000003 | | query end | … waiting in the “Opening tables” state. Now this behavior with respect…
Post: How to convert MySQL's SHOW PROFILES into a real profile
February 20, 2012 By 12 Comments
… demonstrate: mysql> SET profiling=1; mysql> pager cat > /dev/null mysql> SELECT…query_id GROUP BY STATE ORDER BY Total_R DESC; +———————-+———-+——-+——-+————–+ | STATE | Total_R | Pct… | 26.74 | 1 | 0.0461750000 | | Sending data | 0.018478 | 10.70 | 3 | 0.0061593333 …
Post: Write contentions on the query cache
September 5, 2012 By 5 Comments
… 0.000002 | | Sending data | 0.003407 | | Waiting for query cache lock | 0.000003 | | Waiting on query cache mutex | 0.000003 | | Sending data | 0…MySQL need so many accesses to the query cache lock? The answer is in the way the query cache works. Simply stated…
Post: MySQL 5.6 vs MySQL 5.5 and the Star Schema Benchmark
March 11, 2013 By 7 Comments
…MySQL 5.6.10 at the MySQL 5.5.30 data…state = p2.state order by p1.duration desc; +—–+———————-+———–+———-+———–+———–+——-+——-+————–+————–+——-+——-+ | seq | state… | 12 | Sending data | 33….
Post: How FLUSH TABLES WITH READ LOCK works with Innodb Tables
March 23, 2012 By 20 Comments
…State | Info | Rows_sent | Rows_examined | Rows_read | +——-+——+———–+———-+————+——+——————————+——————————+———–+—————+———–+ | 10219 | root | localhost | dumptest | Query | 688 | Sending data…
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
… inside InnoDB 442 mysql tables in use 1, locked 0 MySQL thread id 8079, query id 728899 localhost root Sending data select sql_calc… inside InnoDB 166 mysql tables in use 1, locked 0 MySQL thread id 8078, query id 728898 localhost root Sending data select sql_calc… lock structure. For each of connections for MySQL there will be ether not started state if there is no active Innodb transaction…
Post: Percona XtraDB Cluster: Failure Scenarios with only 2 nodes
July 25, 2012 By 6 Comments
…: Local state seqno (6) is greater than group seqno (5): states diverged. Aborting to avoid potential data loss. Remove ‘/var/lib/mysql//grastate.dat’ file and restart if you wish to continue. (FATAL) at galera/src/replicator_str.cpp:state_transfer_required… (TO: 19) 2012-07-24 11:42:51.292 INFO: Sending state transfer request: ‘trivial’, size: 7 2012-07-24 11:42…
Post: The perils of InnoDB with Debian and startup scripts
January 28, 2009 By 13 Comments
…mysql> show processlist; +——+——————+—————-+————- | Id | User | State | Info +——+——————+—————-+————- | 7 | debian-sys-maint | NULL | CHECK TABLE tableA… | 739 | user | | NULL | 4776 | user | | NULL | 6318 | user | Sending data…
Post: Using any general purpose computer as a special purpose SIMD computer
May 16, 2011 By 5 Comments
…the words of the Constitution of the United States of America as an example. It is …“words” by duplicating the entire set multiple times. mysql> load data infile ‘/tmp/words’ into table words (chars);…parallelism, then performance will be poor. — SQL TO SEND TO SHARDS: Array ( [0] => SELECT word AS `…
