I’ve entered the world of NTP servers and recently spun up a server in Hong Kong which has just been added to the pool. I’m planning on starting low and slowly incrementing the Net speed as I don’t know if the CPU can handle 1 Gbit of throughput. Currently it’s at 12 Mbit.
I chose Hong Kong as I noticed there weren’t many servers there and read on the forums about how heavy Asia can be in terms of requests.
As I’m brand new to this, are there any tips that veteran NTP server owners would like to share? chrony config “must haves” or anything pertaining to NTP server ownership?
One thing I would suggest is to keep an eye on the traffic to and from the server. Have you got any monitoring in place? One thing you will see is LOTS and LOTS of requests coming from mostly one network. I am talking thousands of requests per second. To protect your server I suggest you look at chrony rate limiting and possibly iptables rate limiting. Sometimes the number of incoming requests can flood your link which stops the monitor checks and your server is dropped out of the pool for a while.
Have a look through the chrony.conf documents to learn about the rate settings. The settings I am using are:
# Allow requests from anywhere
allow
# increase client monitoring limit
# clientloglimit 300000000 uses about < 15%% of mem on 1GB instance
clientloglimit 100000000
# rate limit. Interval means 2 to the power of -3 = 0.125 so a packet every 1/8 second
ratelimit interval -3
One of the tools I use to monitor things is vnstat. It can produce a useful status image. My latest is
As the NTP protocol sends and receives similar sized packets the incoming and outgoing network traffic should be sililar but as you can see the light green lines on the right show that the incoming network traffic is far larger than the outgoing traffic. The rate limiters are busy at the moment.
My thoughts are to, as you are doing, increase the connection speed setting slowly and see how the server handles things.
and welcome to the pool.