[Nagiosplug-devel] check_ntp (Was: Flight 1.4.8, ready for boarding)

Thomas Guyot-Sionnest dermoth at aei.ca
Wed Apr 4 19:37:58 CEST 2007


On 03/04/07 02:29 AM, sean finney wrote:
> hey again :)
> 
>> Please also note that I still can't get the jitter on my sun box
>> (solaris.beaubien.net). According to Holger this could be due to the
>> byte order, though running check_ntp on that sun box still give me the
>> same results (is that expected?).
> 
> i wouldn't be surprised if it were either a byte-order issue or a 32/64
> bit thing.  i'd done my best to properly use ntoh[sl]/hton[sl] where
> appropriate, but it's possible i've missed something, or that there's a
> mistake buriend in all the bit-mangling going on.

Hi Sean,

The problem with xntpd it that it doesn't have a jitter value (ntp v3).
I'll work up a patch a bit different than what I sent but basically
it'll do the same: take dispersion in place for jitter.

While we were working on this check, me and Holger raised up a few
issues. I worked up a todo list and I'd like to share it with you. Only
the older ntp client support would go in before the 1.4.8 release.

1. Older ntp server support (I'm working on it)

2. The offset and jitter doesn't change on every call, so there's no
reason to poll 4 times and compute the average. I'd like to remove all
code related to that.

3. Allow to use -H multiple times

3a. Do one lookup for the servers and store an array of IPs for the
various functions. (Is it worth it? Will avoid code duplcation
implementing #4)

4. When multiple servers are specified (either multiple IP per hostname
or multiple -H aguments, check the jitter for all servers.

5. Look into the possibility of storing some of the sent header in a
linked list on write and then match them on reads. That will allow to
send all packets as fast as possible (ex. when checking the jitter of
all sync candidates) and also to easily drop odd packets. If put in a
separate routine that would also allow to easily loop for additional
packets and append the data. (Any other suggestion?)

Thanks,

Thomas




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