… people use mysqldump –single-transaction to get consistent backup for their Innodb tables without making database read only. In most cases…SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */; /*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */; /*!40111 SET SQL_NOTES=@OLD_SQL_NOTES */; — Dump …
Comment: Introducing new type of benchmark
February 26, 2012 By 16 Comments
… webservers. It just makes sens to apply it to databases too. . single-file serving is tested by setting a number of concurrent… typical user session If we are to translate this to databases, we could replace “static file” with a “simple select”, and… take into account (size of data set, usage of persistent connection) – and there are even more in web benchmarking: how long…
Post: How FLUSH TABLES WITH READ LOCK works with Innodb Tables
March 23, 2012 By 20 Comments
…, so you might get a feel you can’t connect to the database at all (use mysql -A in this case, to… rows in set (0.00 sec) As result this means single run away select can effectively cause downtime if you use…
Post: MySQL Limitations Part 4: One thread per connection
October 27, 2010 By 14 Comments
… MySQL handles connections, allocating one thread per connection to the server. MySQL is a single process with multiple threads. Not all databases are architected… a connection. Connection pools and persistent connections combined with a large number of application servers can lead to a situation where the database server…
Comment: Finding your MySQL High-Availability solution – The questions
October 17, 2009 By 36 Comments
…the article you are assuming a single database / applicaiton. For example for a single database you can achieve higher writes… becomes unavailable (best case) * mysql connection are unresponsive connection happen very slowly * mysql connection are unresponsive connection hangs indefinitely when …
Post: PHP Sessions - Files vs Database Based
March 27, 2007 By 38 Comments
… level, which means they also will be serialized for single user on database level. If you change to store PHP sessions in… session behavior with MySQL Sessions ? If you have dedicated connection to session database and use Innodb tables for your session storage you… you do not use persistent connections you even do not have to release lock – as soon as connection is closed the lock…
Post: MySQL extensions for hosting
April 24, 2008 By 11 Comments
…each customer utillizes the database. Having many different users running their queries on a single database instance means …’\G *************************** 1. row *************************** User: hosting2 Total_connections: 84 Concurrent_connections: 0 Connected_time: 20 Busy_time: 1 Rows_fetched…
Post: MySQL Connection Timeouts
April 19, 2011 By 2 Comments
… how MySQL accepts connection. There is single main thread which is accepting connections coming to LISTEN sockets. Once there is connection coming it it… listen queue to overflow. Lets look at the database which accepts 1000 of connects/sec in average. This is a high number… and tearing down connections. Consider using persistent connections or connection pool at least for applications which are responsible for most of connections being created.
Post: Optimizing slow web pages with mk-query-digest
April 7, 2011 By 14 Comments
… only works when persistent connections or connection pools aren’t used and is only accurate when single mysql connection is used during execution of a request. If you are seeking to reduce the load on the database server…, 97% no # Tmp table on 0% yes, 99% no # String: # Databases prod_db # Hosts localhost # InnoDB trxID 1153145C (2/0%), 11531626…
Post: Connecting orphaned .ibd files
May 13, 2011 By 12 Comments
… all data, indexes and system buffers are stored in a single tablespace. This is typicaly one or several ibdata files. A… from a user(you can see them in information_scheme database in Percona Server though). The structure of these tables is… than in every InnoDB page. How let’s connect actor.ibd from sakila database taken from some MySQL server. 0. Create empty…
