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I have a problem in my AWS Windows cluster with the clocks as well. We have a mobile game with a tournaments feature, and tournaments can be as short as 5 minut

I have a problem in my AWS Windows cluster with the clocks as well. We have a mobile game with a tournaments feature, and tournaments can be as short as 5 minutes. So, it's important that all the clients get the same "end time". Normally, at least 10% of the VMs are between 5 and 20 seconds off from the average. By default, the VMs are syncing their time to an NTP server, but it just doesn't seem to be enough. I haven't changed any settings as of yet. What are some of the things I could do on Windows box to sync up the clocks in my cluster? Scheduled shell scripts to force more clock syncs? Or maybe something on the application level?

bradknowles 12y ago
First off, Windows isn't the greatest client for trying to get good timesync. The way the OS usually handles interrupts isn't sufficiently precise and accurate. That said, it's not uncommon for real-hardware Windows clients to get decent timesync down into the double-digit millisecond range -- usually about ~40-50ms or so. Second, you're trying to run them in a virtualization environment, and that plays holy hell with whatever good timesync you might otherwise have been able to get. And AWS is probably about as bad as you could reasonably get in this regard -- VMWare has had a long time to get to where they are with regards to timesync for client OSes, and that's not particularly good. So, your best bet may be to run NTP clients on the Windows machines, but to set them up to run at an artificially high rate of updates. Or maybe even run ntpdate periodically against good real-hardware time servers that are available to you. You're starting off with both hands tied behind your back, and that's a hard place to come back from.