sensu-plugins/sensu-plugins-mysql

## Sensu-Plugins-mysql

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## Functionality

## Files
 * bin/check-cloudwatch-mysql-sensu.rb
 * bin/check-mysql-alive.rb
 * bin/check-mysql-status.rb
 * bin/check-mysql-connections.rb
 * bin/check-mysql-disk.rb
 * bin/check-mysql-innodb-lock.rb
 * bin/check-mysql-threads.rb
 * bin/check-mysql-query-result-count.rb
 * bin/check-mysql-select-count.rb
 * bin/check-mysql-msr-replication-status.rb
 * bin/metrics-mysql-graphite.rb
 * bin/metrics-mysql-multiple-select-count.rb
 * bin/metrics-mysql-processes.rb
 * bin/metrics-mysql-raw.rb
 * bin/metrics-mysql.rb
 * bin/metrics-mysql-query-result-count.rb
 * bin/metrics-mysql-select-count.rb
 * bin/mysql-metrics.sql

## Usage
**metrics-mysql**
```
{
    "mysql":{
        "hostname": "localhost",
        "username": "sensu_user",
        "password": "sensu_user_pass"
    }
}
```

**metrics-mysql-graphite** example:
```bash
/opt/sensu/embedded/bin$ /opt/sensu/embedded/bin/ruby metrics-mysql-graphite.rb --host=localhost --port=3306 --user=collectd --pass=tflypass --socket=/data/mysql.sock
```

**check-mysql-connections** example
```bash
/opt/sensu/embedded/bin$ /opt/sensu/embedded/bin/ruby check-mysql-connections.rb --host=localhost --port=3306 --user=collectd --pass=tflypass --socket=/data/mysql.sock
```

**check-mysql-connections** example with ini file to hide credentials
```bash
$ /opt/sensu/embedded/bin/check-mysql-connections.rb --host=<DBHOST> --ini=/etc/sensu/my.ini
```

**check-mysql-alive** example
```bash
$ /opt/sensu/embedded/bin/check-mysql-alive.rb --host=<DBHOST> --ini=/etc/sensu/my.ini --ini-section=customsection
```

**check-mysql-disk** example (note: you must supply max disk size)
```bash
$ /opt/sensu/embedded/bin/check-mysql-disk.rb --host=<DBHOST> --ini=/etc/sensu/my.ini --size <MAX_DB_SIZE>
```

**check-mysql-innodb-lock** example
```bash
$ /opt/sensu/embedded/bin/check-mysql-innodb-lock.rb --host=<DBHOST> --ini=/etc/sensu/my.ini
```

**check-mysql-threads** example
```bash
$ /opt/sensu/embedded/bin/check-mysql-threads.rb --host=<DBHOST> --ini=/etc/sensu/my.ini --warnlow 0
```

**check-mysql-replication-status** example
```bash
$ /opt/sensu/embedded/bin/check-mysql-replication-status.rb --host=<SLAVE> --ini=/etc/sensu/my.ini
```

**check-mysql-msr-replication-status** example
```bash
$ /opt/sensu/embedded/bin/check-mysql-replication-status.rb --host=<SLAVE> --ini=/etc/sensu/my.ini
```

**check-mysql-query-result-count** example
```bash
/opt/sensu/embedded/bin$ /opt/sensu/embedded/bin/ruby check-mysql-query-result-count.rb --host=localhost --port=3306 --user=collectd --pass=tflypass --socket=/data/mysql.sock --warning 1 --critical 10 --query 'SELECT DISTINCT(t.id) FROM table t where t.failed = true'
```

**check-mysql-select-count** example
```bash
/opt/sensu/embedded/bin$ /opt/sensu/embedded/bin/ruby check-mysql-select-count.rb --host=localhost --port=3306 --user=collectd --pass=tflypass --socket=/data/mysql.sock --warning 30000 --critical 50000 --query 'SELECT count(*) FROM table t'
```

**metrics-mysql-query-result-count** example
```bash
/opt/sensu/embedded/bin$ /opt/sensu/embedded/bin/ruby metrics-mysql-query-result-count.rb --host=localhost --port=3306 --user=collectd --pass=tflypass --socket=/data/mysql.sock --query 'SELECT DISTINCT(t.id) FROM table t where t.failed = true'
```

**metrics-mysql-select-count** example
```bash
/opt/sensu/embedded/bin$ /opt/sensu/embedded/bin/ruby metrics-mysql-select-count.rb --host=localhost --port=3306 --user=collectd --pass=tflypass --socket=/data/mysql.sock --query 'SELECT COUNT(*) FROM table t'
```

**metrics-mysql-multiple-select-count** example
```bash
/opt/sensu/embedded/bin$ /opt/sensu/embedded/bin/metrics-mysql-multiple-select-count.rb --host=localhost --port=3306 --user=collectd --pass=tflypass --socket=/data/mysql.sock --query '{"t1_count":"SELECT COUNT(*) FROM table t1", "t2_count":"SELECT COUNT(*) FROM table t2"}'
```
### Security

In keeping with the principle of least privilege you should create a new user with the minimum required permissions. See the table below for minimum permissions for each check.

| Check                                  | Permissions                                               |
|:---------------------------------------|:----------------------------------------------------------|
| check-mysql-alive.rb                   | `SELECT`                                                  |
| check-mysql-connections.rb             | `SELECT`                                                  |
| check-mysql-disk.rb                    | `SELECT`                                                  |
| check-mysql-innodb-lock.rb             | `PROCESS`                                                 |
| check-mysql-query-result-count.rb      | depends on query                                          |
| check-mysql-select-count.rb            | `SELECT`                                                  |
| check-mysql-replication-status.rb      | `SUPER` OR `REPLICATION_CLIENT` (the latter is preferable)|
| check-mysql-msr-replication-status.rb  | `SELECT`                                                  |
| check-mysql-status.rb                  | `SELECT`                                                  |
| check-mysql-threads.rb                 | `SELECT`                                                  |
| metrics-mysql-graphite.rb              | `SELECT`                                                  |
| metrics-mysql-processes.rb             | `SELECT`                                                  |
| metrics-mysql-query-result-count.rb    | depends on query                                          |
| metrics-mysql-select-count.rb          | depends on query                                          |
| metrics-mysql-multiple-select-count    | depends on query                                          |
| metrics-mysql-raw.rb                   | `SELECT`                                                  |
| metrics-mysql.rb                       | `INSERT` into `sensumetrics.sensu_historic_metrics`       |

I would recommend using different users when you need to have more than RO access (`REPLICATION_CLIENT` or using the metrics handler) to limit the potential ramifications of that user being compromised.

## Installation

[Installation and Setup](http://sensu-plugins.io/docs/installation_instructions.html)

## Notes
The ruby executables are install in path similar to `/opt/sensu/embedded/lib/ruby/gems/2.0.0/gems/sensu-plugins-mysql-0.0.4/bin`

## Troubleshooting
When used in `chef`, if the dependencies are missing, an error may abort the chef-client run:
```bash
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of
necessary libraries and/or headers.  Check the mkmf.log file for more
details.  You may need configuration options.
```
This may be fixed by installing the mysql client library before the plugin:
```ruby
# http://serverfault.com/questions/415392/install-mysql-gem-for-use-in-chef-client
package "libmysqlclient-dev" do
  action :install
end

sensu_gem 'sensu-plugins-mysql' do version '0.0.4' end

```