… the thing to check for. VARIABLE=${VARIABLE:-Threads_connected} You need to change the threshold to 15, and the variable to Threads_running. Check… script can log into MySQL (if necessary, put a password into .my.cnf, or in the MYSQLOPTIONS variable). Now you can simply…. There are many things that can cause a stall in MySQL, and they usually begin microscopically and get worse over time…
Post: MySQL 5.5 lock_wait_timeout: patience is a virtue, and a locked server
February 28, 2013 By 5 Comments
… Locking Changes in MySQL 5.5, the hot topic these days is MySQL 5.6, but there was an important metadata locking change in MySQL… concerning this change apropos pt-online-schema-change, I discovered something about lock_wait_timeout that shocked me. From the MySQL 5.5 docs for lock_wait_timeout: This variable…
Post: Percona Toolkit 2.1.8 released today with beta support for MySQL 5.6
January 9, 2013 By Leave a Comment
…: pt-table-chcecksum pt-online-schema-change pt-archive pt-mysql-summary pt-heartbeat pt-variable-advisor pt-config-diff pt-deadlock-logger…. Fixed bug 1015590: pt-mysql-summary doesn’t handle renamed variables in Percona Server 5.5. Some renamed variables had caused the Percona… UTC regardless of the server or MySQL time zone. Fixed bug 1079341: pt-online-schema-change checks for foreign keys on MyISAM…
Post: Introducing the pmp-check-mysql-status Nagios Plugin
March 29, 2012 By 2 Comments
… of status counters and variables. This is the pmp-check-mysql-status plugin, which can perform computations on status variables. By default, I… variable or another counter Add, subtract, multiply, and divide counters or variables Transform a ratio into a percentage Compute the rate of change…
Post: Replication of the NOW() function (also, time travel)
November 28, 2012 By 6 Comments
… didn’t change the clock of the server or change anything in the database configuration settings. mysql> SELECT NOW(),SYSDATE(); +———————+———————+ … is the TIMESTAMP variable, which is a special MySQL variable that can be set by the MySQL client. MySQL adds special events …
Post: MySQL Users Conference Presentation Proposals
October 24, 2007 By 12 Comments
…MySQL Variables Tuning This session takes practical approach to MySQL variable tuning. Instead of giving you theoretical guesses on what would be right variable…
Post: Debugging MySQL SSL problems
November 8, 2012 By Leave a Comment
… it via PRM’s automation that does the CHANGE MASTER for you. Eliminate the variables. The customer provided me with the CA… for the mysql cli that will output the actual SSL error (nary to be found!) Running: SHOW VARIABLES LIKE ‘%ssl%’ (mysql was adamant… got what I had been looking for: # mysql –ssl-ca=/data/mysql/etc/mysql/DigiCertCA.pem … mysql> … ————–Connection id: 101 Current database: Current user…
Post: Is MySQL 5.6 slower than MySQL 5.5?
February 18, 2013 By 23 Comments
… I have not tuned MySQL 5.6 for best performance going with defaults outside of few variables MySQL Sandbox sets explicitly but yet this is likely course of action for many MySQL users out there, also was not change of defaults in MySQL 5.6 had more reasonable…
Post: Should we give a MySQL Query Cache a second chance ?
April 10, 2011 By 64 Comments
… 10 years, with very little changes done to the core of original implementation which appeared in MySQL 4.0 Query Cache was… is appealing to improve performance for MySQL Applications ? Make it Lockless Can we re-implement MySQL Query Cache so it is lockless… stable. We can also get query_cache_ttl as session variable, which is very helpful for connections opened to the slaves…
Post: MySQL Server Memory Usage
May 17, 2006 By 21 Comments
… me the question how should they estimate memory consumption by MySQL Server in given configuration. What is the formula they could… to be impractical. Here is why: List of rarely considered MySQL Server Memory Requirements Thread buffers can be allocated more than… you get in practice and how memory consumption reacts to changing various variables. For example you may find out increasing sort_buffer…
