Hi,
incidentally I looked some weeks ago on the web server access log file of
the SpamAssassin rules update files mirror sa-update.fossies.org and found
surprisingly that at noon (midday) the log file has a size much more than
the roughly expected half of a complete daily log.
Just for curiosity I plotted the number of the GET requests for update
files (tarballs) per hour and saw an interesting characteristics with a
great peak between 6 and 7 a.m. (GMT+2). Ok, the main reason is probably
the publication time (mostly between 5 and 6 a.m. GMT+2) with a delay til
the user's sa-update scripts are running. But the structure of the curves
with the some curious (?) mimima is a little bit "surprisingly" to me but
it is constant and reproducible.
A simple example text plot for a single day is attached (more accurate
plots are available under the URL given below).
But more interesting and "irritating" was the fact that I found in the
main update time often (at least 100-1000) entries with the HTTP status
404 ("Not Found"). That motivated me to write a primitive script to
analyze the reason by monitoring the update status resp. update times of
the new published rules update files.
First I checked the local web log files assuming that a 404 request to an
update file means that an external client had the information about a new
file that the local mirror sa-update.fossies.org has not yet available
resp. not yet fetched (via rsync).
Additionally I checked the local DNS server (of the server provider) and
the DNS servers I found responsible for the domain spamassassin.org
ns2.pccc.com.
ns2.ena.com.
c.auth-ns.sonic.net.
b.auth-ns.sonic.net.
a.auth-ns.sonic.net.
via the command
dig @<server> 3.3.3.updates.spamassassin.org txt +short
The plots and an extract of the script output you can find under
https://fossies.org/~schleusener/sa-update.mirror_analysis/
User: sa
PW: update
The main reason for the 404 errors seems to be that the mirroring script
is started as cronjob on sa-update.fossies.org only every 10 minutes.
Probably better would be to check the original nameservers (the local
nameserver answers according the TTL only with a freshness delay of max.
one hour) and start only a rsync job if the response shows that a new file
is available.
If all mirror servers would use update frequencies not smaller than 10
minutes an idea may be also to set/change the DNS TXT entry only 10
minutes after the release (availability) of a new update file.
Additionally I found that the synchronization of the above DNS servers
seems delayed by some minutes. The "best" DNS server seems to be
"ns2.ena.com" since it always as first one provides the new versions.
Maybe this behaviour is a little bit related to the current thread with
the subject "repeated sa-update problems" on the users list.
Regards
Jens
--
FOSSIES - The Fresh Open Source Software archive
mainly for Internet, Engineering and Science
https://fossies.org/
Number of hourly GET requests for SpamAssassin
update files on mirror "sa-update.fossies.org"
4008 +---------+---------+---------+---------+-------+
| |
| + requests/hour +-----+ |
| | |
3008 + | | +
| | | |
| | + |
| -+-+ | |
2008 + + | +
| / | |
| -+-+ +- |
|+ +-+-+- |
1008 + +- -+-+- +
| +- -+ +|
| +- -+-+-+-+ |
| + |
0 +---------+---------+---------+---------+-------+
0 5 10 15 20 24
hour (GMT+2)
