We wanted to setup a loadbalanced web cluster in AWS for expansion. My first inclination was to use ELB for this, but I soon learned that ELB doesn’t let you allocate a static IP, requiring you to refer to it only by DNS name. This would be OK except for the fact that our current DNS provider, Dyn, requires IP addresses when using their GSLB (geo-based load balancer) service.
Rather than let this derail the whole project, I decided to look into the software options available for loadbalancing in EC2. I’ve been a fan of hardware load balancers for a while, sort of looking down at software-based solutions without any real rationale, but in this case I really had no choice so I figured I’d give it a try.
My first stop was Nginx. I’ve used it before in a reverse-proxy scenario and like it. The problem I had with it was that it doesn’t support active polling of nodes – the ability to send requests to the webserver and mark the node as up or down based on the response. As far as I can tell, using multiple upstream servers in Nginx allows you to specify max_fails and fail_timeout, however a “fail” is determined when a real request comes in. I don’t want to risk losing a real request – I like active polling.
Continue reading “Load balancing in EC2 with Nginx and HAProxy”
I got my wife an iPad 2 for Christmas and she soon started complaining about the Wifi dropping its connection. I suggested she try turning off the “auto join” wifi setting, but that didn’t help. She’d be doing something and get the “Sorry, there’s no internet connection” error every 5-10 minutes. We’ve had FiOS for quite a while and we have 8 or 9 other devices connected (including Macs & iPhones) to the router without issue, so this seemed weird. I was starting to think it was a problem with the iPad, but we went to a friend’s house and used his wifi (with a Netgear router) and the iPad had no issues.
Back home, I logged into the router and tried assigning her iPad a static IP through DHCP. I had her release and renew and she got the new IP but the problem continued. Since we ruled out a problem with the iPad and I knew there was nothing “wrong” with the router, I figured I’d check and see if there are any reported issues with iPads and the Verizon router. Sure enough, there are. The first thing I clicked on, Fix for Verizon FIOS vs. iPad Wi-Fi Issues, suggested changing the wifi channel from “Automatic” to “6” (it also suggests switching from WEP to WPA2-PSK, which I’ve always been using). I did that and it hasn’t dropped the wifi connection at all in the past 3 hours. Very odd issue. If I could get into the Actiontec (or the iPad for that matter) I’d like to check the logs and see what’s actually happening, but a win’s a win.