June 19, 2013

Post: Choosing a MySQL HA Solution - Post-Webinar Q&A

replication filters on the slave, as described in the MySQL manual. You can configure the slave to only replicate…bet that MySQL is up and running. That said, there are plenty of other MySQL and OS-level status …with –skip-grant-tables and insert a few rows into an InnoDB table, but trying to …

Post: Ultimate MySQL variable and status reference list

MySQL manual, especially the option …replication_delayblogpercona.commanual innodb_rollback_on_timeoutblogpercona.commanual Innodb_row_lock_current_waitsblogpercona.commanual Innodb_row_lock_timeblogpercona.commanual Innodb_row….commanual Innodb_truncated_status_writesblogpercona.commanual innodb_…

Post: How does MySQL Replication really work?

replication capacity, I don’t think we have one that covers the very basics of how MySQL replication really works on the high level…in which case these are write queries Row based – in this case these are… the replication status variables mentioned above to the master binary log status from the…

Post: InnoDB's gap locks

One of the most important features of InnoDB is the row level locking. This feature provides better concurrency under heavy write load… phantom reads and to get a consistent Statement based replication. To accomplish that, row level locking databases also acquire gap locks. What is… INNODB STATUS: —TRANSACTION 72C, ACTIVE 755 sec 4 lock struct(s), heap size 1248, 3 row lock(s), undo log entries 1 MySQL

Post: Estimating Replication Capacity

mysql> select * from information_schema.user_statistics where user=”#mysql_system#” \G *************************** 1. row *************************** USER: #mysqlreplication the most. It however works only with statement level replication

Comment: 7 Reasons why MySQL Quality will never be the same

… be mentioned by “weakest link” – if Partitions or Row Level Replication is unstable in MySQL 5.1 GA it is unstable. At the same… it works well or it does not. I see GA status not as seal of quality but rather as a promise…

Post: Shard-Query EC2 images available

mysql> show table status like ‘ontime_fact’G *************************** 1. row *************************** Name: ontime_fact Engine: InnoDB Version: 10 Row_format: Compact Rows: 6697533 Avg_row…-relay-log innodb-replication-delay=# innodb-rollback-…good plan optimizer-prune-level=0 partition=ON …

Post: MySQL Server Variables - SQL layer or Storage Engine specific.

… memory tables. So first MySQL versions did not bother … tables have “holes” (deleted rows) which can help significantly….expire_logs_days This is replication/binlogging related options – when …MyISAM and Innodb. Some SQL level items as Query Cache …by mutexes in SHOW MUTEX STATUS. Was intended to work …

Post: Heikki Tuuri answers to Innodb questions, Part II

….0 series compact row format was implemented which…Q36: There have been several MySQL bugs opened about multi-core… operations for different levels of concurrency, specifically around…separate computer, maybe a replication slave. Can you … where id=5 show innodb status: Hash table size 10624987,…

Post: Heikki Tuuri Innodb answers - Part I

level READ COMMITTED, then InnoDB normally does not lock the ‘gaps’, and it does not lock rowsreplication, and remember that the execution is not serializable. PZ: Cool. This is one of little known new features in MySQL…threads waiting for semaphores in SHOW INNODB STATUS), you can try to disable …