… Instance 68.4 GB of memory 26 EC2 Compute Units (8 virtual cores with 3.25 EC2 Compute Units each) 1690… to the MySQL configuration. MySQL Configuration I used Percona Server 5.5.22-55 for the tests. Following is the configuration that… = 8 innodb_write_io_threads = 4 innodb_file_per_table = 1 ## Disabling query cache query_cache_size = 0 query_cache_type = 0 You…
Post: Testing Intel SSD 520
May 1, 2012 By 7 Comments
… even for small amount of threads. For 8 threads the 95% response time is 0.69ms. Now let me get back to… still interesting in asynchronous IO, as MySQL 5.5 uses async IO for writes. Maybe 8 threads in the first graph is too… !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id…
Comment: Joining many tables in MySQL - optimizer_search_depth
April 23, 2012 By 5 Comments
…. So yes, the default should be changed to ‘0‘ which means “choose automatically”, which in turn means “…7, this function grows very fast – 7! = 5040, while 8! = 40320. The worst-case complexity of MySQL’s … with the change to plan pruning in MySQL 5.6. Ideally, the server should analyze the query …
Comment: InnoDB's gap locks
April 13, 2012 By 14 Comments
…> select * from t; +——+——–+ | i | c | +——+——–+ | 1 | miguel | | 3 | andy | | 5 | aaron | | 8 | repls | +——+——–+ Then I start two transactions, session1 and session2: session1… | | 3 | andy | | 5 | aaron | | 8 | repls | +——+——–+ session1> update t set c=”peter” where c=”andy”; Query OK, 0 rows affected (0.00 sec) Again…
Post: Join Optimizations in MySQL 5.6 and MariaDB 5.5
April 4, 2012 By 2 Comments
…=on’ optimizer_switch=’join_cache_bka=on’ join_cache_level=8 join_buffer_size=6M mrr_buffer_size=6M Note that… lowest query time is for MySQL 5.6 which takes 0.16s less as compared to MySQL 5.5 While with join_buffer_size…=6M MariaDB 5.5 Hash Join Disabled w/ join_buffer_size=4M & mrr_buffer_size=4M Created_tmp_disk_tables 0 0 0 0 0 0 Created_tmp…
Post: Introducing new type of benchmark
February 25, 2012 By 16 Comments
… us following intervals (in sec) between events: 0.61, 0.43, 1.55, 0.18, 0.01, 0.76, 0.09, 1.26, … Or if we…): As you see interval is far from being strict 0.5 sec, but 0.5 is the mean of this random generation function. On… working threads? You can see it from following graph (1-8 threads): The queue piles up, waiting time grows, and the…
Comment: InnoDB thread concurrency
March 19, 2012 By 4 Comments
…like follows: ——– FILE I/O ——– I/O thread 0 (thread id: 18578) state: waiting for completed …completed aio requests (read thread) I/O thread 5 (thread id: 18583) state: waiting for completed …completed aio requests (write thread) I/O thread 8 (thread id: 18586) state: waiting for completed …
Comment: How to recover a single InnoDB table from a Full Backup
March 22, 2012 By 7 Comments
… been detected. InnoDB: Progress in %: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17… 99 100 done. 120323 4:38:52 InnoDB: Error: page 0 log sequence number 6094071743825 InnoDB: is in the future! Current… log files. See InnoDB: http://dev.mysql.com/doc/refman/5.5/en/forcing-innodb-recovery.html InnoDB: for more information.
Post: Product to try: MySQL/MariaDB-Galera 0.8
June 13, 2011 By 34 Comments
… heard my suggestions and the new 0.8 release looks very promising. Well, it took 1.5 years to fix the limitations and…, trust me. So Galera 0.8 comes with many nice features: Works with MySQL 5.1 and MariaDB 5.1. The latest is more…/Galera 0.8, binaries are available from Launchpad. The downside of MySQL/Galera is that it is based on standard InnoDB 5.1…
Post: MySQL 5.0, 5.1 and Innodb Plugin CPU Efficiency
December 3, 2008 By 15 Comments
… couple of weeks ago so MySQL 5.0.67, MySQL 5.1.29 and Innodb Plugin 1.0.1 were used which are not… in testing. MySQL 5.1 is 4% slower than MySQL 5.0 with two cores and just 2% slower with 8 cores, thus showing a bit better scalability. MySQL 5.1 plugin…
