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A standalone service for monitoring MySQL and exposing its health through an HTTP interface for use with TCP load balancers (like haproxy) that support out-of-band health checks using HTTP.
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MySQL Health is a standalone HTTP server that will respond with a 200 status code when MySQL is operating as expected.

This script is intended to be used in conjuction with HAProxy "option httpchk" for a TCP load balancer distributing load across mysql servers.


  1. If you get the error "caught DBI::InterfaceError exception 'Could not load driver (uninitialized constant MysqlError)'" on OSX, try doing this: export DYLD_LIBRARY_PATH="/usr/local/mysql/lib:$DYLD_LIBRARY_PATH"


Add this line to your application's Gemfile:

gem 'mysql_health'

And then execute:

$ bundle

Or install it yourself as:

$ gem install mysql_health


Usage: mysql_health options
        --check:master               Master health check
        --check:slave                Slave health check
        --check:allow-overlapping    Allow overlapping health checks (default: false)
        --check:interval INTERVAL    Check health every INTERVAL (default: 10s)
        --check:delay DELAY          Delay health checks for INTERVAL (default: 0s)
        --check:dsn DSN              MySQL DSN (default: DBI:Mysql:mysql:localhost)
        --check:username USERNAME    MySQL Username (default: root)
        --check:password PASSWORD    MySQL Password (default: )
    -l, --server:listen ADDR         Server listen address (default:
    -p, --server:port PORT           Server listen port (default: 3305)
    -d, --server:daemonize           Daemonize the process (default: false)
    -P, --server:pid-file PID-FILE   Pid-File to save the process id (default: false)
        --log:level LEVEL            Logging level (default: INFO)
        --log:file FILE              Write logs to FILE (default: STDERR)
        --log:age DAYS               Rotate logs after DAYS pass (default: 7)
        --log:size SIZE              Rotate logs after the grow past SIZE bytes (default: 10485760)


Start the server on port 1234 and check the status of the slave every 30 seconds:

mysql_health --check:slave --check:interval 30 --server:port 1234

Start the server on port 1234 and check the status of the master every 30 seconds:

mysql_health --check:master --check:interval 30 --server:port 1234


  1. Fork it
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Commit your changes (git commit -am 'Added some feature')
  4. Push to the branch (git push origin my-new-feature)
  5. Create new Pull Request
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