…alive while still keeping MySQL connection open, others will serve static content such as images which also does not need MySQL connection open. In optimal …should get fresh connection ID so if you track web requests in MySQL Logs by connection ID it would still work. MySQL has change_user…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…MySQL manual, especially the…concurrent_insertblogpercona.commanual connect_timeoutblogpercona.commanual …open_filesblogpercona.commanual Innodb_os_log_fsyncsblogpercona.commanual Innodb_os_log_pending_fsyncsblogpercona.commanual Innodb_os_log_pending_writesblogpercona.commanual Innodb_os_log…
Post: How to Monitor MySQL with Percona's Nagios Plugins
February 22, 2012 By 8 Comments
… example, a pile-up of connections all trying to open or close tables can indicate LOCK_open contention. Replication is delayed or stopped… handle or log this error appropriately. The pmp-check-mysql-status plugin can be configured to alert when Threads_connected approaches max_connections too…
Post: How to debug long-running transactions in MySQL
March 8, 2011 By 6 Comments
…is a long-running transaction. If a transaction remains open for a very long time without committing, and …connection. I then sniff TCP traffic for a while, use mk-query-digest to convert this into a query log, and examine the log. In MySQL 5.1 and newer with the …
Post: MySQL Limitations Part 4: One thread per connection
October 27, 2010 By 14 Comments
… about the way MySQL handles connections, allocating one thread per connection to the server. MySQL is a … to avoid it. And with 5000 connections open, you get 5000 threads in the server…MySQL replication is one of the core, fundamental features — and it’s single-threaded and relies on the binary log…
Post: Scaling problems still exist in MySQL 5.5 and Percona Server 5.5
May 20, 2011 By 11 Comments
…load in the application by aggregating query log with mk-query-digest. When I …cur_open_with_no_init_func,row_sel_get_clust_rec_for_mysql,row_search_for_mysql…mysql_select,handle_select,execu te_sqlcom_select,mysql_execute_command,mysql_parse,dispatch_command,do_command,do_handle_one_connection…
Post: Rare evil MySQL Bug
November 20, 2009 By 7 Comments
…to see MySQL 5.4.2 in the funny state. When you see bug happening you would see MySQL log …Depending on the case you may be able to connect to MySQL through Unix Socket or TCP/IP or neither…pretty high socket number – probably because of large innodb_open_files I tested with in this case – which …
Comment: MySQL Server Memory Usage
September 1, 2006 By 18 Comments
…=/tmp/mysql.sock pid-file=/var/run/mysql/mysql.pid datadir=/db/disk2/mysql/data log-bin=/var/log/mysql/log log-slow-queries=/var/log/mysql/slow-queries.log max_connections=650 open_files_limit=6144 max_connect_errors…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
…MySQL server. The first step is to log into the machine via SSH and open… | Variable_name | Value | +———————————–+———————-+ | Aborted_clients | 205174 | | Aborted_connects | 29 | | Binlog_cache_disk_use | 0 | |…
Comment: Database problems in MySQL/PHP Applications
November 6, 2006 By 12 Comments
…mysql reports max connections reached and freezes, with a bunch of processes waiting to finish. Also, mysql…= 32M # table_cache=20M # open-files-limit=20000 table_cache = 3072 open_files_limit = 9216 … #innodb_log_group_home_dir = /usr/local/mysql/data/ #innodb_log_arch_dir = /usr/local/mysql/data…
