Pablowe

Nagios MySQL Plug-Ins

There currently exist many plugins for MySQL to use with Nagios. Many of them, however, are not version-independent, leaving organizations that use multiple versions of MySQL to either install multiple plugins or not monitor specific versions of MySQL. As such, I’ve compiled what I consider to be the most useful checks into a single plugin: check_mysql

Usage:
     check_mysql check_name [options]

     Options:
       --args|a     Optional arguments.  Comma-separated.  Check-specific.
       --critical|c The level at which a critical alarm is raised.  Check-specific.
       --database   The database to use (defaults to mysql)
       --help|?     Display this message and exit
       --hostname|H     The target MySQL server host (defaults to localhost)
       --password|p The password of the MySQL user
       --port       The port MySQL is listening on (defaults to 3306)
       --user|u     The MySQL user used to connect
       --version|V  Display version information and exit
       --warning|w  The level at which a warning is raised.  Check-specific.

     defaults are:

     ATTRIBUTE                  VALUE
     -------------------------- ------------------
     args                       No default value
     critical                   Check-specific
     database                   mysql
     help                       FALSE
     host                       localhost
     password                   No default value
     port                       3306
     timeout                    10 seconds
     user                       No default value
     verbose                    1 (out of 3)
     version                    FALSE
     warning                    Check-specific

Current Checks Supported:

* connect – Check to see whether or not one can connect to MySQL (USAGE)
* repl_io – Check to see whether on not the IO Replication thread is running (REPLICATION CLIENT)
* repl_sql – Check to see whether or not the SQL Replication thread is running (REPLICATION CLIENT)
* repl_sbm – Check how many seconds behind the master the slave is (REPLICATION CLIENT)
* mysql_query – Run a given query, test if it executes properly (SELECT)
* connections – Test if the percentage of used connections is over a given threshold (PROCESS)

I am open to requests for additional checks etc.

Drizzle

Last night I attended the San Francisco MySQL Meetup Group to hear Brian Aker talk about Drizzle. Heretofore, I was generally uninterested in Drizzle because I didn’t pay enough attention to what it was actually trying to accomplish. After his presentation, I am anxious to play with it in a meaningful way! The features that sold me:

• utf8 as the default (only?) charset
• No more SQL_MODE (behaving strict-like by default)
• Pluggable Authentication
• A much smarter communication protocol
• 64-bit only *(EDIT: Stewart has informed me that 32-bit is supported, but Drizzle has been optimized for 64-bit … I’m still counting it as a win)
• Did I mention Pluggable Authentication?
• Defaults to transaction-capable

One feature I’m hoping to see come up soon:

• Online Upgrades

Why would I want that? Upgrading is very easy, you think. Since drizzle is designed to be used with huge (by today’s standards) machines with 128+G RAM, 128+ CPU Cores, one must assume that the data sets used will correspondingly be huge. So huge, in fact, that it will take hours (days?) for the caches to warm up! An online upgrade capability may allow for caches to stay hot during the upgrade process rather than having to operate in a degraded state for a long time after an upgrade.