I talk with lot of people who are really interested in Percona XtraDB Cluster (PXC) and mostly they are interested in PXC as a high-availability solution. But, what they tend not to think too much about is if moving from async to synchronous replication is right for their application or not. Facts about Galera replication [...]
Benchmarking Percona Server TokuDB vs InnoDB
May 7, 2013 By 32 Comments
After compiling Percona Server with TokuDB, of course I wanted to compare InnoDB performance vs TokuDB. I have a particular workload I’m interested in testing – it is an insert-intensive workload (which is TokuDB’s strong suit) with some roll-up aggregation, which should produce updates in-place (I will use INSERT .. ON DUPLICATE KEY UPDATE statements [...]
Percona Server 5.5.30-30.2 rerelease fixes non-restart issue
April 24, 2013 By Leave a Comment
In our last 5.5 series release of Percona Server, we included a regression in the RPM packaging that prevented the server from restarting following an upgrade — instead, the server would remain stopped after the upgrade was completed regardless of its state before updating. This caused some problems for some users, especially if automatic upgrading was configured [...]
How to recover table structure from InnoDB dictionary
April 22, 2013 By 4 Comments
To recover a dropped or corrupt table with Percona Data Recovery Tool for InnoDB you need two things: media with records(ibdata1, *.ibd, disk image, etc.) and a table structure. Indeed, there is no information about the table structure in an InnoDB page. Normally we either recover the structure from .frm files or take it from [...]
Percona Server for MySQL 5.5.30-30.2 now available
April 10, 2013 By 8 Comments
Percona is glad to announce the release of Percona Server for MySQL 5.5.30-30.2 on April 10, 2013 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.5.30, including all the bug fixes in it, Percona Server 5.5.30-30.2 is now the current stable release in the 5.5 series. All of Percona‘s software is open-source and free, all the details of [...]
Investigating MySQL Replication Latency in Percona XtraDB Cluster
March 3, 2013 By 13 Comments
I was curious to check how Percona XtraDB Cluster behaves when it comes to MySQL replication latency — or better yet, call it data propagation latency. It was interesting to see whenever I can get stale data reads from other cluster nodes after write performed to some specific node. To test it I wrote quite a [...]
Announcing Percona Server for MySQL version 5.5.29-30.0
February 26, 2013 By Leave a Comment
Percona is glad to announce the release of Percona Server for MySQL version 5.5.29-30.0 on February 26th, 2013 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.5.29, including all the bug fixes in it, Percona Server 5.5.29-30.0 is now the current stable release in the 5.5 series. All of Percona‘s software is open-source and free, all the details [...]
MySQL 5.5 and MySQL 5.6 default variable values differences
February 21, 2013 By 8 Comments
As the part of analyzing surprising MySQL 5.5 vs MySQL 5.6 performance results I’ve been looking at changes to default variable values. To do that I’ve loaded the values from MySQL 5.5.30 and MySQL 5.6.10 to the different tables and ran the query:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 | mysql [localhost] {msandbox} (test) > select var55.variable_name,left(var55.variable_value,40) value55, left(var56.variable_value,40) var56 from var55 left join var56 on var55.variable_name=var56.variable_name where var55.variable_value!=var56.variable_value; +---------------------------------------------------+------------------------------------------+------------------------------------------+ | variable_name | value55 | var56 | +---------------------------------------------------+------------------------------------------+------------------------------------------+ | PERFORMANCE_SCHEMA | OFF | ON | | PID_FILE | /mnt/data/sandboxes/msb_5_5_30/data/mysq | /mnt/data/sandboxes/msb_5_6_10/data/mysq | | CHARACTER_SETS_DIR | /mnt/nfs/dist/mysql-5.5.30-linux2.6-x86_ | /mnt/nfs/dist/mysql-5.6.10-linux-glibc2. | | PERFORMANCE_SCHEMA_MAX_COND_INSTANCES | 1000 | 836 | | PERFORMANCE_SCHEMA_MAX_MUTEX_INSTANCES | 1000000 | 3282 | | OLD_PASSWORDS | OFF | 0 | | INNODB_STATS_ON_METADATA | ON | OFF | | PERFORMANCE_SCHEMA_EVENTS_WAITS_HISTORY_SIZE | 10 | 5 | | PERFORMANCE_SCHEMA_EVENTS_WAITS_HISTORY_LONG_SIZE | 10000 | 100 | | PERFORMANCE_SCHEMA_MAX_RWLOCK_INSTANCES | 1000000 | 1724 | | PERFORMANCE_SCHEMA_MAX_TABLE_HANDLES | 100000 | 2223 | | INNODB_LOG_FILE_SIZE | 5242880 | 50331648 | | BASEDIR | /mnt/nfs/dist/5.5.30 | /mnt/nfs/dist/5.6.10 | | BACK_LOG | 50 | 80 | | OPEN_FILES_LIMIT | 1024 | 5000 | | INNODB_AUTOEXTEND_INCREMENT | 8 | 64 | | MAX_CONNECT_ERRORS | 10 | 100 | | SORT_BUFFER_SIZE | 2097152 | 262144 | | LC_MESSAGES_DIR | /mnt/nfs/dist/mysql-5.5.30-linux2.6-x86_ | /mnt/nfs/dist/mysql-5.6.10-linux-glibc2. | | MAX_ALLOWED_PACKET | 1048576 | 4194304 | | JOIN_BUFFER_SIZE | 131072 | 262144 | | TMPDIR | /mnt/data/sandboxes/msb_5_5_30/tmp | /mnt/data/sandboxes/msb_5_6_10/tmp | | TABLE_OPEN_CACHE | 400 | 2000 | | INNODB_VERSION | 5.5.30 | 1.2.10 | | INNODB_BUFFER_POOL_INSTANCES | 1 | 8 | | QUERY_CACHE_SIZE | 0 | 1048576 | | SLOW_QUERY_LOG_FILE | /mnt/data/sandboxes/msb_5_5_30/data/dpe0 | /mnt/data/sandboxes/msb_5_6_10/data/dpe0 | | TABLE_DEFINITION_CACHE | 400 | 1400 | | PORT | 5530 | 5610 | | QUERY_CACHE_TYPE | ON | OFF | | REPORT_PORT | 5530 | 5610 | | PERFORMANCE_SCHEMA_MAX_FILE_INSTANCES | 10000 | 1556 | | SQL_MODE | | NO_ENGINE_SUBSTITUTION | | INNODB_OLD_BLOCKS_TIME | 0 | 1000 | | LOG_ERROR | /mnt/data/sandboxes/msb_5_5_30/data/msan | /mnt/data/sandboxes/msb_5_6_10/data/msan | | VERSION_COMPILE_OS | linux2.6 | linux-glibc2.5 | | THREAD_CACHE_SIZE | 0 | 9 | | PLUGIN_DIR | /mnt/nfs/dist/5.5.30/lib/plugin/ | /mnt/nfs/dist/5.6.10/lib/plugin/ | | SYNC_RELAY_LOG | 0 | 10000 | | GENERAL_LOG_FILE | /mnt/data/sandboxes/msb_5_5_30/data/dpe0 | /mnt/data/sandboxes/msb_5_6_10/data/dpe0 | | PERFORMANCE_SCHEMA_MAX_TABLE_INSTANCES | 50000 | 445 | | SYNC_RELAY_LOG_INFO | 0 | 10000 | | SLAVE_LOAD_TMPDIR | /mnt/data/sandboxes/msb_5_5_30/tmp | /mnt/data/sandboxes/msb_5_6_10/tmp | | SECURE_AUTH | OFF | ON | | VERSION | 5.5.30 | 5.6.10 | | INNODB_CONCURRENCY_TICKETS | 500 | 5000 | | INNODB_PURGE_THREADS | 0 | 1 | | INNODB_OPEN_FILES | 300 | 2000 | | INNODB_DATA_FILE_PATH | ibdata1:10M:autoextend | ibdata1:12M:autoextend | | INNODB_PURGE_BATCH_SIZE | 20 | 300 | | PERFORMANCE_SCHEMA_MAX_THREAD_INSTANCES | 1000 | 224 | | SOCKET | /tmp/mysql_sandbox5530.sock | /tmp/mysql_sandbox5610.sock | | INNODB_FILE_PER_TABLE | OFF | ON | | SYNC_MASTER_INFO | 0 | 10000 | | DATADIR | /mnt/data/sandboxes/msb_5_5_30/data/ | /mnt/data/sandboxes/msb_5_6_10/data/ | | OPTIMIZER_SWITCH | index_merge=on,index_merge_union=on,inde | index_merge=on,index_merge_union=on,inde | +---------------------------------------------------+------------------------------------------+------------------------------------------+ 56 rows in set (0.05 sec) |
Lets go over to see what are the most important changes [...]
Edge-case behavior of INSERT…ODKU
October 27, 2012 By 6 Comments
A few weeks back, I was working on a customer issue wherein they were observing database performance that dropped through the floor (to the point of an outage) roughly every 4 weeks or so. Nothing special about the environment, the hardware, or the queries; really, the majority of the database was a single table with [...]
Hidden columns of query_review_history table
August 28, 2012 By Leave a Comment
You can use pt-query-digest to process a MySQL slow query log and store historical values for review trend analysis into query_review_history table. According to its official documentation you can populate many columns in that table but there are other important ones such as ‘user’, ‘host’, ‘db’ which are not included by default. I will explain [...]
