… roll-up sum for 10, 100, 1000 records in the main table. and transactions for this workload are: $ID=monotonically increasing… innodb_log_files_in_group = 2 innodb_log_block_size=4096 #####plugin options innodb_read_io_threads = 16 innodb_write_io_threads = 4 innodb_io_capacity = 4000 innodb…
Post: trx descriptors: MySQL performance improvements in Percona Server 5.5.30-30.2
April 12, 2013 By 3 Comments
… performance that still stands in the way of InnoDB scalability is the trx_list scan on consistent … consistent read view sees them or not. The main limitation is obvious: if you want to benefit …s a notable drop in throughput starting from 256 threads. But Percona Server’s scalability is the same …
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
…. ————– ROW OPERATIONS ————– 0 queries inside InnoDB, 0 queries in queue 1 read views open inside InnoDB Main thread process no. 10099, id 88021936, state… are open inside Innodb – this is when transaction was started but no statement is currently active, state of Innodb main thread which controls scheduling…
Post: Can Innodb Read-Ahead reduce read performance ?
June 26, 2007 By 2 Comments
… at SHOW INNODB STATUS: ——– FILE I/O ——– I/O thread 0 state: waiting for i/o request (insert buffer thread) I/O thread 1… ————– ROW OPERATIONS ————– 8 queries inside InnoDB, 3 queries in queue 12 read views open inside InnoDB Main thread process no. 3956, id 1157658976, state…
Post: InnoDB thread concurrency
June 5, 2006 By 4 Comments
…innodb–; ENTER; } retry: if (entered_thread < innodb_thread_concurrency) { entered_threads++; thread->n_tickets_to_enter_innodb = innodb_concurrency_tickets; ENTER; } if (innodb_thread_sleep_delay > 0) { thread_sleep(innodb_thread…
Post: Purge Thread Spiral of Death
June 10, 2010 By 5 Comments
I just wrote a large post on reasons for innodb main tablespace excessive growth and I thought it would make sense … when problems often starts to happen. Now instead of purge thread simply operating in memory it has to perform IO which… can be controlled), using innodb_max_purge_lag or enable separate purge thread (or threads) via innodb_use_purge_thread if you’re running Percona…
Post: Innodb Performance Optimization Basics
November 1, 2007 By 75 Comments
… for more details, check out detailed guide on tuning innodb buffer pool innodb_log_file_size – This depends on your recovery speed… especially on a lot of short write transactions. innodb_thread_concurrency=8 Even with current Innodb Scalability Fixes having limited concurrency helps. The…. innodb_file_per_table – If you do not have too many tables use this option, so you will not have uncontrolled innodb main…
Post: Helgrinding MySQL with InnoDB for Synchronisation Errors, Fun and Profit
November 24, 2011 By 2 Comments
…:424 This is a race between srv_monitor_thread and srv_error_monitor_thread InnoDB threads storing to srv_last_monitor_time. It’s…) ==9090== by 0×561388: main (mysqld.cc:4504) ==9090== This conflicts with a previous read of size 8 by thread #14 ==9090== at… 0×632436: init_server_components() (mysqld.cc:4035) ==9090== by 0×561388: main (mysqld.cc:4504) ==9090== followed by a later acquisition of…
Post: Reasons for run-away main Innodb Tablespace
June 10, 2010 By 2 Comments
… it ? There are few things which are always stored in main tablespace – these are system tables, also known as data dictionary… first you can use innodb_max_purge_lag to make a threads doing modifications slow down if purge thread can’t keep up…’re running XtraDB you can also use innodb_use_purge_thread to use dedicated purge thread, which works a bit faster as it…
Post: Paul McCullagh answers your questions about PBXT
November 20, 2009 By 2 Comments
… consistent snapshot. Does PBXT have a maintenance thread like InnoDB‘s main thread? PBXT has several system threads, that are responsible for various maintenance tasks… constantly and is the main source of asynchronous I/O in the engine. The Sweeper is a thread unique to the PBXT… with the current solution: create a background thread to do recovery asynchronously. So the thread can wait for the LOCK_plugin to…
