Haproxy provides ways to add and remove servers on the fly and a lot of other things. This gem lets you use that via a nice ruby API, so that it can be used in applications for deployments testing and gathering statistics.
This was extracted out of our rolling deployment scheme.
For this to work haproxy
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Version 1.4 and above
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Should be running with the following configuration.
stats socket /home/ubuntu/haproxysock level adminIt means that haproxy will open a socket at /home/ubuntu/haproxysock. You can specify the level to use. We use
admin. But I believe operator/admin is needed for the enable/disable/setting weights to work correctly.
Install the latest version of the gem with the following command...
$ gem install haproxy_manager
require "haproxy_manager"
gem "haproxy_manger", :require => false
Add the following where approporiate(eg. deploy.rb) require "haproxy_manager"
haproxy = HAProxyManager::Instance.new ('path to haproxy socket')
haproxy.backends # Lists all the backends available
haproxy.servers("foo-farm") # List all the servers available in the given backend
haproxy.disable("preprod-app", "foo-farm") # Disables a server in a specific farm
haproxy.disable("preprod-app") # Disables a server with a given name in all the available backends
haproxy.enable("preprod-app", "foo-farm") # Enables a server in a specific farm
haproxy.enable("preprod-app") # Enables a server with a given name in all the available backends
haproxy.weight("preprod-app", "foo-farm", "10") # Sets the weight to 10. The value can be between 0 - 255
haproxy.weight("preprod-app", "foo-farm", "10%") # Reduces the weight of the server by 10%(of the value specified in the config)
haproxy.weight("preprod-app", "foo-farm", "0%") # Reduces the weight of the server to 0. Useful for disabling the server.
haproxy.weight("preprod-app", "foo-farm", "100%") # Increases the weight to the original configuration value. useful to bring the server back up after reducing the weight to 0%
haproxy.weight("preprod-app", "foo-farm") # Returns the current weights setting. The response is something like this.
{current => 10, initial=> 12}
haproxy.info # provides information about the haproxy setup. The following is how it looks like. Most fields are self describing.
{"Name" => "HAProxy", "Version" => "1.5-dev11", "Release_date" => "2012/06/04", "Nbproc" => "1", "Process_num" => "1", "Pid" => "4084", "Uptime" => "58d 3h50m53s", "Uptime_sec" => "5025053", "Memmax_MB" => "0", "Ulimit-n" => "40029", "Maxsock" => "40029", "Maxconn" => "20000", "Hard_maxconn" => "20000", "Maxpipes" => "0", "CurrConns" => "0", "PipesUsed" => "0", "PipesFree" => " 0", "ConnRate" => " 0", "ConnRateLimit" => " 0", "MaxConnRate" => " 69", "Tasks" => " 10", "Run_queue" => " 1", "Idle_pct" => "100", "node" => " The server name", "description" => "Our Awesome Load balancer"}
haproxy.reset_counters # Clears HAProxy counters. Except Global counters
haproxy.reset_counters(:all) # Clears All HAProxy counters. This is the equivalent of a restart
haproxy.stats # Retrives the HAProxy stats from the server. The result looks something like this.
{"foo-farm"=>
{"FRONTEND"=>{"qcur"=>"", "qmax"=>"", "scur"=>"0", "smax"=>"150", "slim"=>"2000", "stot"=>"165893", "bin"=>"38619996", "bout"=>"3233457381", "dreq"=>"0", "dresp"=>"0", "ereq"=>"6504", "econ"=>"", "eresp"=>"", "wretr"=>"", "wredis"=>"", "status"=>"OPEN", "weight"=>"", "act"=>"", "bck"=>"", "chkfail"=>"", "chkdown"=>"", "lastchg"=>"", "downtime"=>"", "qlimit"=>"", "pid"=>"1", "iid"=>"1", "sid"=>"0", "throttle"=>"", "lbtot"=>"", "tracked"=>"", "type"=>"0", "rate"=>"0", "rate_lim"=>"0", "rate_max"=>"69", "check_status"=>"", "check_code"=>"", "check_duration"=>"", "hrsp_1xx"=>"0", "hrsp_2xx"=>"136147", "hrsp_3xx"=>"2128", "hrsp_4xx"=>"6654", "hrsp_5xx"=>"20955", "hrsp_other"=>"9", "hanafail"=>"", "req_rate"=>"0", "req_rate_max"=>"144", "req_tot"=>"165893", "cli_abrt"=>nil, "srv_abrt"=>nil},
"preprod-app"=>{"qcur"=>"0", "qmax"=>"9", "scur"=>"0", "smax"=>"60", "slim"=>"60", "stot"=>"139066", "bin"=>"34839081", "bout"=>"3222850212", "dreq"=>"", "dresp"=>"0", "ereq"=>"", "econ"=>"3", "eresp"=>"725", "wretr"=>"0", "wredis"=>"0", "status"=>"UP", "weight"=>"10", "act"=>"1", "bck"=>"0", "chkfail"=>"583", "chkdown"=>"148", "lastchg"=>"10893", "downtime"=>"257935", "qlimit"=>"", "pid"=>"1", "iid"=>"1", "sid"=>"1", "throttle"=>"", "lbtot"=>"114847", "tracked"=>"", "type"=>"2", "rate"=>"0", "rate_lim"=>"", "rate_max"=>"88", "check_status"=>"L7OK", "check_code"=>"200", "check_duration"=>"150", "hrsp_1xx"=>"0", "hrsp_2xx"=>"135827", "hrsp_3xx"=>"2128", "hrsp_4xx"=>"147", "hrsp_5xx"=>"230", "hrsp_other"=>"0", "hanafail"=>"0", "req_rate"=>"", "req_rate_max"=>"", "req_tot"=>"", "cli_abrt"=>"20", "srv_abrt"=>"11"},
"preprod-bg"=>{"qcur"=>"0", "qmax"=>"0", "scur"=>"0", "smax"=>"3", "slim"=>"30", "stot"=>"31", "bin"=>"14333", "bout"=>"380028", "dreq"=>"", "dresp"=>"0", "ereq"=>"", "econ"=>"0", "eresp"=>"9", "wretr"=>"4", "wredis"=>"2", "status"=>"DOWN", "weight"=>"5", "act"=>"1", "bck"=>"0", "chkfail"=>"4", "chkdown"=>"10", "lastchg"=>"2538799", "downtime"=>"4603702", "qlimit"=>"", "pid"=>"1", "iid"=>"1", "sid"=>"2", "throttle"=>"", "lbtot"=>"6", "tracked"=>"", "type"=>"2", "rate"=>"0", "rate_lim"=>"", "rate_max"=>"2", "check_status"=>"L4CON", "check_code"=>"", "check_duration"=>"0", "hrsp_1xx"=>"0", "hrsp_2xx"=>"16", "hrsp_3xx"=>"0", "hrsp_4xx"=>"0", "hrsp_5xx"=>"0", "hrsp_other"=>"0", "hanafail"=>"0", "req_rate"=>"", "req_rate_max"=>"", "req_tot"=>"", "cli_abrt"=>"1", "srv_abrt"=>"0"}, "preprod-test"=>{"qcur"=>"0", "qmax"=>"0", "scur"=>"0", "smax"=>"0", "slim"=>"30", "stot"=>"0", "bin"=>"0", "bout"=>"0", "dreq"=>"", "dresp"=>"0", "ereq"=>"", "econ"=>"0", "eresp"=>"0", "wretr"=>"0", "wredis"=>"0", "status"=>"DOWN", "weight"=>"5", "act"=>"1", "bck"=>"0", "chkfail"=>"0", "chkdown"=>"1", "lastchg"=>"5102839", "downtime"=>"5102839", "qlimit"=>"", "pid"=>"1", "iid"=>"1", "sid"=>"3", "throttle"=>"", "lbtot"=>"0", "tracked"=>"", "type"=>"2", "rate"=>"0", "rate_lim"=>"", "rate_max"=>"0", "check_status"=>"L4CON", "check_code"=>"", "check_duration"=>"0", "hrsp_1xx"=>"0", "hrsp_2xx"=>"0", "hrsp_3xx"=>"0", "hrsp_4xx"=>"0", "hrsp_5xx"=>"0", "hrsp_other"=>"0", "hanafail"=>"0", "req_rate"=>"", "req_rate_max"=>"", "req_tot"=>"", "cli_abrt"=>"0", "srv_abrt"=>"0"},
"BACKEND"=>{"qcur"=>"0", "qmax"=>"84", "scur"=>"0", "smax"=>"150", "slim"=>"200", "stot"=>"159082", "bin"=>"38619996", "bout"=>"3233457381", "dreq"=>"0", "dresp"=>"0", "ereq"=>"", "econ"=>"19991", "eresp"=>"734", "wretr"=>"4", "wredis"=>"2", "status"=>"UP", "weight"=>"10", "act"=>"1", "bck"=>"0", "chkfail"=>"", "chkdown"=>"148", "lastchg"=>"10893", "downtime"=>"300268", "qlimit"=>"", "pid"=>"1", "iid"=>"1", "sid"=>"0", "throttle"=>"", "lbtot"=>"114853", "tracked"=>"", "type"=>"1", "rate"=>"0", "rate_lim"=>"", "rate_max"=>"144", "check_status"=>"", "check_code"=>"", "check_duration"=>"", "hrsp_1xx"=>"0", "hrsp_2xx"=>"135843", "hrsp_3xx"=>"2128", "hrsp_4xx"=>"147", "hrsp_5xx"=>"20955", "hrsp_other"=>"9", "hanafail"=>"", "req_rate"=>"", "req_rate_max"=>"", "req_tot"=>"", "cli_abrt"=>"21", "srv_abrt"=>"11"}}}