Merge lp:~robert-ayres/charms/precise/mysql/added-readme into lp:charms/mysql

[Robert Ayres]

Added README

[Juan L. Negron (negronjl)]

Reviewing this now.

-Juan

[Juan L. Negron (negronjl)]

Approved ..

Merged.

-Juan

review: Approve

=== added file 'README.md'
--- README.md	1970-01-01 00:00:00 +0000
+++ README.md	2013-01-15 17:52:20 +0000
@@ -0,0 +1,98 @@
+# Overview
+
+MySQL is a fast, stable and true multi-user, multi-threaded SQL database server.
+SQL (Structured Query Language) is the most popular database query language in
+the world. The main goals of MySQL are speed, robustness and ease of use.
+
+Percona is fork of MySQL by Percona Inc. which focuses on maximizing
+performance, particularly for heavy workloads. It is a drop-in replacement for
+MySQL and features XtraDB, a drop-in replacement for the InnoDB storage engine.
+
+[http://www.mysql.com](http://www.mysql.com)
+
+[http://www.percona.com/software/percona-server](http://www.percona.com/software/percona-server)
+
+# Usage
+
+## General
+
+To deploy a MySQL service:
+
+    juju deploy mysql
+
+Once deployed, you can ssh into the deployed service and access the
+MySQL console as the MySQL root user:
+
+    juju ssh <unit>
+    mysql -u root -p
+    # enter root password - /var/lib/juju/mysql.passwd
+
+To change deployment to a Percona server:
+
+    juju set mysql flavor=percona
+
+## Optimization
+
+You can tweak various options to optimize your MySQL deployment:
+
+* max-connections - Maximum connections allowed to server or '-1' for default.
+
+* preferred-storage-engine - A comma separated list of storage engines to
+  optimize for. First in the list is marked as default storage engine. 'InnoDB'
+  or 'MyISAM' are acceptable values.
+
+* tuning-level - Specify 'safest', 'fast' or 'unsafe' to choose required
+  transaction safety. This option determines the flush value for innodb commit
+  and binary logs. Specify 'safest' for full ACID compliance. 'fast' relaxes the
+  compliance for performance and 'unsafe' will remove most restrictions.
+
+* dataset-size - Memory allocation for all caches (InnoDB buffer pool, MyISAM
+  key, query). Suffix value with 'K', 'M', 'G' or 'T' to indicate unit of
+  kilobyte, megabyte, gigabyte or terabyte respectively. Suffix value with '%'
+  to use percentage of machine's total memory.
+
+* query-cache-type - Specify 'ON', 'DEMAND' or 'OFF' to turn query cache on,
+  selectively (dependent on queries) or off.
+
+* query-cache-size - Size of query cache (no. of bytes) or '-1' to use 20%
+  of memory allocation.
+
+Each of these can be applied by running:
+
+    juju set <service> <option>=<value>
+
+e.g.
+
+    juju set mysql preferred-storage-engine=InnoDB
+    juju set mysql dataset-size=50%
+    juju set mysql query-cache-type=ON
+    juju set mysql query-cache-size=-1
+
+## Replication
+
+MySQL supports the ability to replicate databases to slave instances. This
+allows you, for example, to load balance read queries across multiple slaves or
+use a slave to perform backups, all whilst not impeding the master's
+performance.
+
+To deploy a slave:
+
+    # deploy second service
+    juju deploy mysql mysql-slave
+
+    # add master to slave relation
+    juju add-relation mysql:master mysql-slave:slave
+
+Any changes to the master are reflected on the slave.
+
+Any queries that modify the database(s) should be applied to the master only.
+The slave should be treated strictly as read only.
+
+You can add further slaves with:
+
+    juju add-unit mysql-slave
+
+## Monitoring
+
+This charm provides relations that support monitoring via either Nagios or
+Munin. Refer to the appropriate charm for usage.