More about EC2 and NTP

There is a lot of back and forth about using NTP on Amazon's EC2 servers. Here are some links:

• https://serverfault.com/questions/100978/do-i-need-to-run-ntpd-in-my-ec2-instance
• https://web.archive.org/web/20150215172010/http://www.metamul.com/blog/ntp-isnt-required-under-ec2-or-is-it/
• https://stackoverflow.com/questions/14623650/how-to-deal-with-the-amazon-ec2s-clock-drift
• https://docs.riak.com/riak/kv/2.2.3/using/performance/amazon-web-services/#clocks
• https://forums.aws.amazon.com/thread.jspa?messageID=364758
• https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/set-time.html

A summary then:

Yeah, run NTP. It'll work 80% of the time. It won't work on some other EC2 servers (based on the instance type) but won't error out, a harmless no-op. There is has been reported cases of NTP failing & erroring out when attempting to set the time, but that also seems like a case of outdated kernels (either in the Xen domU or on the guest). So update your VM and terminate/cycle it to hopefully move it do a host Amazon server with the newer kernel.