also I forgot to mention for heartbeat I use keepalived http://www.keepalived.org/ I found hearbeat a little difficult to implement but keepalived by comparison is a breeze to setup. Forget about multiple A records. That's a naive approach and entirely unnecessary. As other's have pointed out just setup a virtual ip using keepalived (or heartbeat or maybe something similar) and point your A record to that virtual ip. On Fri, Mar 4, 2011 at 11:17 AM, Tim Dunphy <bluethundr at gmail.com> wrote: >>OK, so what's good? For my requirements, HAProxy is excellent. It >> handled sticky sessions well, performs monitoring of each host, allows >> dynamic adding/removing of servers, as well as maintenance modes. >> It's very easy to install and configure. I'm using is as the backend >> to apache that is acting as an SSL termination point. It's been very >> high performing for us and I know a lot of big sites use it as well. >> The only question I would have with it is handling of video, as we >> only use it for typical web traffic, just high bandwidth stuff like >> that. > >> Also, make sure any load balancer you have is redundant and has some >> kind of failover, using something like pacemaker, heartbeat, etc... > > I second the vote for HAProxy. It's one excellent free (as in beer) > load balancer that is very easy to setup and configure. > > One big site that uses it is 37 signals (the makers of basecamp and > campfire among other things). HAProxy is capable of handling a lot of > traffic apparently. I use it with a shared docroot living on and NFS > mount. Works really great! It balances two centos vm's as primary with > a physical freebsd host acting as a fallback. > > Other good choices include nginx with the upstream fair plugin and > #pound from apsis. > > http://www.apsis.ch/pound/ > http://wiki.nginx.org/LoadBalanceExample > > Any of the above (pound, nginx or haproxy) will handle sticky sessions > skillfully. > > > As to hardware load balancers I think that Netscaler by citrix > deserves an honorable mention: > > > http://deliver.citrix.com/go/citrix/WWAD0111Q1NSGOOGLECLOUDWP?gclid=CNDzzIantacCFQFM5QodslJN_w > > But like any hardware lb they're certainly not cheap!! I remember when > my last company was considering which load balancer to go with the > contenders were Zeus, F5 and Citrix Netscaler. > > I think they're all good products, but I remember when the F5 salesman > came by, part of his sales pitch was "Ok, if you don't go with us I > can understand why you would go with Netscaler. But Zeus? Really, > guys?" > > > > On Fri, Mar 4, 2011 at 10:09 AM, Brian Mathis <brian.mathis at gmail.com> wrote: >> On Thu, Mar 3, 2011 at 6:43 PM, Todd <slackmoehrle.lists at gmail.com> wrote: >>> Hi All, >>> Can anyone help me hash out how best to load balance a website that is >>> getting considerable traffic? In the past I only have experience with BigIP >>> where you have a load balancing device that keeps track and send traffic to >>> the best server possible at the time. This was a proprietary system that I >>> think was something Dell rebranded. >>> Right now, the whole site is is 400gb of video, HTML5, Apache, PHP, MySQL, >>> runs on a single box with 16gb of RAM and mirrored /var/www/html (2x1tb raid >>> level drives). I have a Comcast 50/10 connection, 5 statics and I am seeing >>> about 125 unique visitors a day. The site runs fine, but in anticipation of >>> more traffic as well as a learning experience I would like to load balance. >>> Obviously I need a second server just like the one it is running on now. I >>> will probably spec something out that is capable of 32gb of RAM. >>> What about a dedicated load balancing device? What specs should this be? How >>> much RAM, HD, processor? It is sufficient to buy something with a GB NIC and >>> say 4gb of RAM? Can one go slower but more RAM, small HD? I don't really >>> quite know how intensive a task this decision making process is for the load >>> balancer.. >>> Right now, as example, I have an Untangle Firewall and it runs on a old AMD >>> with 2gb RAM, GB NIC and it seems to do just fine. >>> My local computer store has several P4 2.8ghz with 2GB of RAM for like >>> $99.... >>> Can anyone enlighten me on specs, proper setup, caveats....? >>> -Jason >> >> >> You have a lot of issues here, and some unanswered questions. Is the >> load on your site mostly bandwidth use? Do you have users who need to >> login to a system? Is the application designed to run with multiple >> front-ends? It's easy to get very basic load balancing, but your app >> most likely will require "sticky sessions" to ensure the user goes to >> the same backend server every time, and many solutions don't have this >> feature. >> >> Of the free options already listed, here are the problems with them: >> - Round Robin DNS: Provides no additional features other then very >> poor "load spreading" across servers. As soon as you talk about load >> balancing there are usually features you need that this cannot >> provide, like automatic failover, dynamic adding/removing hosts, >> etc... Sticky sessions are simply not possible. RR DNS should not be >> used except in extremely basic situations. >> >> - Linux LVS: This is a good idea on the face of it, but it can open >> up some tricky issues with routing and IP address handling. Also, >> sticky sessions are based on subnet of the IP address, which for many >> corporations using proxies will not work. I have seen companies that >> spread their proxy load across multiple /8 networks, so there's no way >> to sticky them. >> >> >> OK, so what's good? For my requirements, HAProxy is excellent. It >> handled sticky sessions well, performs monitoring of each host, allows >> dynamic adding/removing of servers, as well as maintenance modes. >> It's very easy to install and configure. I'm using is as the backend >> to apache that is acting as an SSL termination point. It's been very >> high performing for us and I know a lot of big sites use it as well. >> The only question I would have with it is handling of video, as we >> only use it for typical web traffic, just high bandwidth stuff like >> that. >> >> Also, make sure any load balancer you have is redundant and has some >> kind of failover, using something like pacemaker, heartbeat, etc... >> _______________________________________________ >> CentOS mailing list >> CentOS at centos.org >> http://lists.centos.org/mailman/listinfo/centos >> > > > > -- > GPG me!! > > gpg --keyserver pool.sks-keyservers.net --recv-keys F186197B > -- GPG me!! gpg --keyserver pool.sks-keyservers.net --recv-keys F186197B