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Post: MySQL Server Variables - SQL layer or Storage Engine specific.
June 8, 2006 By 14 Comments
… with table locks or if LOCK TABLES are used. So in practice this option is used for MyISAM and MEMORY tables. max_write_lock_count Variable which may save you from read starvation if there are constant writes to the table. Works with table locks so…
Comment: What to tune in MySQL Server after installation
October 7, 2009 By 118 Comments
http://blog.taragana.com/index.php/archive/one-mysql-configuration-tip-that-can-dramatically-improve-mysql-performance/ try this max_write_lock_count = 1
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
…———- SEMAPHORES ———- OS WAIT ARRAY INFO: reservation count 13569, signal count 11421 –Thread 1152170336 has waited …as for read-write locks. For these information both for exclusive locks and for shared locks is … values will also grow and innodb_max_purge_lag will become your friend. “…
Post: XtraDB/InnoDB CPU bound benchmarks on 24cores server
December 29, 2008 By 6 Comments
…=1000 innodb_write_io_threads = 16 innodb_read_io_threads = 16 join_buffer_size=1M max_allowed_packet=1M max_connections=3000 max_heap_table_size=64M max_prepared_stmt_count=1000000 query_cache_size=0 skip_grant_tables skip_locking… fixes to rw_locks and to buffer_pool mutex (in rel2). Conclusion: As read-only workload seems fine, read-write cases is…
Post: MySQL 5.6.7-RC in tpcc-mysql benchmark
October 8, 2012 By 22 Comments
….7 locks …write_io_threads = 16 innodb_io_capacity = 20000 innodb_io_capacity_max = 40000 #not innodb options (fixed) port = 3306 back_log = 50 max_connections = 2000 max_prepared_stmt_count=500000 max_connect_errors = 10 table_open_cache = 2048 max_allowed_packet = 16M binlog_cache_size = 16M max…
Post: Another scalability fix in XtraDB
January 23, 2009 By 13 Comments
…=16 to match threads inside InnoDB with count of cores. Results for InnoDB-plugin-1….shared read lock is enough – and we replaced page_hash mutex to page_hash read-write lock. The …for reference InnoDB was run with next parameters: –max_connections=3000 \ –table_cache=2048 \ –query_cache_size=0…
Post: Recovery deleted ibdata1
August 10, 2012 By 9 Comments
…write activity we can either stop application or lock tables: mysql> flush tables with read lock… 363096003 Last checkpoint at 363096003 Max checkpoint age 7782360 To speed… are reachable: mysql> select count(*) from sbtest; +———-+ | count(*) | +———-+ | 1000000 | +———-+ 1 row in set …
Post: Distributed Set Processing with Shard-Query
May 14, 2011 By 27 Comments
…it apart. Projection, GROUP BY, SUM, COUNT, MIN*, and MAX* are distributable. With a little elbow…which supports incrementally maintaining materialized views. While writing Flexviews, I learned how to distribute … the output. There is no external locking or synchronization required. If a query …
Post: Shard-Query EC2 images available
May 11, 2011 By 2 Comments
…6697533 Avg_row_length: 241 Data_length: 1616904192 Max_data_length: 0 Index_length: 539279360 Data… parse time). $ echo “select count(*) from ontime_fact;” | ./run_query Array ( [count(*)] => 135125787 ) 1 rows returned …write-io-threads=4 join-buffer-size=16M key-buffer-size=64M local-infile=on lock…
