RE: single or many haproxy instances
Not sure why you would run multiple HAProxy in one node. I don't understand what you want to do. But... Look into using Consul to help load balance/cluster your HAProxy instances. That is what we are doing. Simple and works great. Think of Consul as a Global load balancing service that works internally. Consul will look at all your instances (HAProxy or whatever) and round-robin or weight load balance to all of them based on health checks you plug in. I don't know if this would solve your prob though. * Justin Franks Lead Operations Engineer SaaS, Cloud, Data Centers Infrastructure Lithium Technologies, Inc 225 Bush St., 15th Floor San Francisco, CA 94104 tel: +1 415 757 3100 x3219 From: Xu (Simon) Chen xche...@gmail.com Sent: Monday, June 30, 2014 7:38 AM To: HAProxy Subject: single or many haproxy instances Hi folks, I am writing a simple load balancer as a service to automate haproxy configuration while providing a simple API to users, who only need to give a few simple specifications of the load balancer they want. I am trying to decide whether to run multiple haproxy instances or a single instance on a particular node. I currently use jinja2 template to combine all services into a single haproxy configuration file and run a single instance of haproxy. Every time, when a service spec is changed, I run check config mode, and only reload the config if the test passes. But I fear that a single incorrect service spec would prevent everyone else from updating their services, unless I maintain some last-known good config for every service. Managing one haproxy instance for every service solves this problem, but I might end up with too many processes on a single box. Any recommendations on which way to go? Is there a recommended max number of haproxy instances per node/core? Thanks. -Simon
How to edit backend members in realtime without HAProxy restart
Hello, We are using Consul, written by the same guys who wrote Vagrant. Really great tool. http://www.consul.io/ Consul is a service registry and discovery and DNS solution among other things. I can create an internal name like 'some.thing.internal' which will resolve to a pool of nodes. So when I do a 'dig + short some.thing.internal' it will return IPaddressA IPaddressB IPaddressC etc... Consul keeps the list of nodes related to a particular URI up to date in real-time. It uses health checks and so on and will round robin the traffic to all the nodes evenly. But I want HAProxy too. So I want HAProxy to say, I see a URI that resolves to N number of IP addresses. I will add the addresses to the backend. I will keep polling the URI. If the address change I will update the backend. How can I accomplish this? What are my options? A cron job to run 'dig + short some.thing.internal' every minute and send that info to HAProxy for backend members? Unix sockets, ALCs and stick-tables? I just want the result that I described above done in real-time so HAProxy restart not required. I don't care how it is accomplished. Thanks in advance for any ideas. * Justin Franks Lead Operations Engineer SaaS, Cloud, Data Centers Infrastructure Lithium Technologies, Inc 225 Bush St., 15th Floor San Francisco, CA 94104 tel: +1 415 757 3100 x3219
Redirect or forwarding behavior question
Let's say my front end is: something.domain01.com I want requests that hit this HAProxy to be redirected or forwarded to: foobar.lobster.net ... which lives inside my network. I want to understand how HAProxy behaves. At startup will HAProxy cache the IP of foobar.lobster.net? Or will HAProxy lookup the name at the time the rule matches that redirects/forwards domain01 to lobster.net? If so how long will HAProxy cache the IP of lobster.net? The net result I want is: If request comes in to front end then HAProxy will redirect/forward to other domain name. Upon redirect/forward HAProxy will lookup the IP of other domain every time, all the time. * Justin Franks Lead Operations Engineer SaaS, Cloud, Data Centers Infrastructure Lithium Technologies, Inc 225 Bush St., 15th Floor San Francisco, CA 94104 tel: +1 415 757 3100 x3219
