… there is approximately 12GB of data in the largest table. You can find the individual SSB query definitions in my previous blog…_table innodb_stats_on_metadata=off innodb_file_format=barracuda innodb_log_buffer_size=32M innodb_buffer_pool_instances=16 metadata_locks_hash_instances=32 table_open_cache_instances=8 sort_buffer_size=128k…
Post: Galera Flow Control in Percona XtraDB Cluster for MySQL
May 2, 2013 By 5 Comments
… is existence of a replication feedback mechanism, unlike anything you find in standard async MySQL replication. It is my belief that… on any node by simply by running “FLUSH TABLES WITH READ LOCK“, or perhaps by “LOCK TABLE“, in which case flow control will kick… easily see flow control if I execute a FLUSH TABLES WITH READ LOCK on node3: [root@node3 ~]# myq_status wsrep Wsrep Cluster…
Comment: Innodb Table Locks
April 8, 2013 By 4 Comments
It’s slightly off topic, but can you elaborate on how to see existing table locks, similar to Postgres’ “pg_locks” command? We have an issue of locking tables, but cannot find which process is causing the lock…tnx
Post: MySQL 5.6 Compatible Percona Toolkit 2.2 Released
March 25, 2013 By 2 Comments
…how. There’s still one noticeable omission: pt-table-sync. It’s still unclear if or …are configurable. Also, we removed –lock-wait-timeout which set innodb_lock_wait_timeout because that now conflicts,…and tcpdump), so you shouldn’t have a problem finding queries to run and compare. pt-query-digest…
Comment: MySQL and Percona Server in LinkBench benchmark
May 11, 2013 By 18 Comments
Yasufumi – it is very nice to hear from you. Linkbench can also be a good test to find performance stalls from the index lock. I think the published version of linkbench partitions the link table. Remove that and the index lock limits performance for IO-bound workloads.
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
… also be used as debugging tool. Next section you will find in SHOW INNODB STATUS is information about currently active transactions… of tables locked by transactions. Innodb does not lock tables for normal operation so number of tables locked normally stays 0, unless it is ALTER TABLE or similar statement, or if LOCK TABLES was…
Post: How to find MySQL queries worth optimizing ?
September 11, 2012 By 6 Comments
… looking at pt-query-digest report it is easy to find slow queries or queries which cause the large portion of….031233 Lock_time: 0.000086 Rows_sent: 0 Rows_examined: 10000000 Rows_affected: 0 Rows_read: 0 # Bytes_sent: 213 Tmp_tables….391612 Lock_time: 0.000121 Rows_sent: 2 Rows_examined: 10000000 Rows_affected: 0 Rows_read: 2 # Bytes_sent: 75 Tmp_tables…
Post: Timezone and pt-table-checksum
September 25, 2012 By 1 Comment
… +———-+————+ | this_crc | master_crc | +———-+————+ | b890c395 | 763d97f1 | +———-+————+ Naturally, pt-table-sync finds this and reports that all 3 rows in this…dsn:h=192.168.1.46,p=…,u=percona lock:1 transaction:1 changing_src:percona.checksums replicate:…
Post: INFORMATION_SCHEMA tables in the InnoDB pluggable storage engine
May 24, 2008 By Leave a Comment
…_RESET | | INNODB_CMPMEM | | INNODB_CMPMEM_RESET | | INNODB_LOCK_WAITS | | INNODB_LOCKS | | INNODB_TRX | +—————————————-+ The _CMP tables show statistics about compression; they contain a… to find out more information on InnoDB locks even in the older versions of InnoDB, but it’s not really easy.) These tables…
Post: MySQL Slow query log in the table
May 31, 2007 By 1 Comment
… LIKE statement. As default table format for slow_log is CSV with no indexes typical operations like finding how many queries were… buffer of slow log queries which is used if log table is locked. One thing which would be rather handy is UDF… SET list of tables which query is using. This would allow for example to find all queries touching given table quickly which is…
