Haproxy on server failure event

failoverhaproxy

I've got a setup with one HAproxy server (frontend) and multiple web-servers (backend). Is it possible to configure HAproxy so that a script is executed when a web-server gets down?

Best Answer

I think what you're asking is you want to send a mail when one of the backend servers goes down, correct? I don't believe there's a way to trigger this from within HAProxy itself. One way to do this is to have a script check the status of the backends periodically and send an email if a backend is down. You can use the HAProxy socket interface to get this info. Docs are here. You'll probably need to parse the output from the show stat command. Good luck!

Related Solutions

HAProxy – How to Add Basic HTTP Access Authentication

I had to do this today myself (because IIS 7.5 bizarrely doesn't actually support authenticating against anything but Windows user accounts or AD!)...

Here's all the code

userlist UsersFor_AcmeCorp
  user joebloggs insecure-password letmein

backend HttpServers
  .. normal backend stuff goes here as usual ..
  acl AuthOkay_AcmeCorp http_auth(UsersFor_AcmeCorp)
  http-request auth realm AcmeCorp if !AuthOkay_AcmeCorp

I documented it a bit better here: http://nbevans.wordpress.com/2011/03/03/cultural-learnings-of-ha-proxy-for-make-benefit/

Haproxy: adding tcplog parameters

My current answer/solution (mentioned in the question) is as follows.

I define a different 'listen' for each port to be bound with a recognisable name.

I then ensure option tcplog is enabled for that frontend.

The logging then provides me the two pieces of information I need. The frontend and backend used.

e.g.

haproxy[18989]: 127.0.0.1:34550 [15/Oct/2003:15:24:28.312] frontend backend/server 0/0/5007 0 cD 0/0/0/0/0 0/0

I parse that log file 'magically' and use that information to present the latest status.

option logasap helps..

Best Answer

Related Solutions

HAProxy – How to Add Basic HTTP Access Authentication

Haproxy: adding tcplog parameters

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