]] Johnny Halfmoon

Hi,

| Well, to my understanding, the way I read out the delivery status is
| already after vcl_deliver has run. The status collection routine is
| called as follows for each backend:
|
| sub vcl_deliver {
|     C{ STATS_UPDATE(www_somesitename_com) }C
| }
|
| So at this point all delivery statusses (stati?) should be known to
| Varnish. This setup has been running succesfully for several months
| and it works for all codes except 206. Am I missing something here?

Yes, the decision on whether to return 200 or 206 is done after
vcl_deliver has run.

| 'We' have a setup here where we have about 30 different sites, big and
| small, all running of a cluster of 3 Varnish servers and log and graph
| the returncodes and several other parameters of each site seperately.
| Not having proper registration of the 206 codes does create a hole in
| our logging, but it has not proven to be an issue yet, although we are
| aiming to have this hole closed some time in the near future.

Is there any particular reason why you're not using
varnishlog/varnishncsa for this, rather than potentially slowing down
the object delivery by doing it inline?

A good reason indeed: Having a bit of VCL code gather the per-site statistics (throughput, hit/miss count, delivery codes) and dumping a few lines of stats to syslog every 30 seconds causes much less load on the servers than having a script parse anywhere between 1.5 to 3MB/second of logs per server.

The only not-so-nice bit of this setup is that the VCL code had to be made artificially thread-aware, and therefor a mutex is used to access the statistics structure, which happens once per access. At extremely high loads, with a large amount of workerthreads active, this might form a potential source of delay, although I doubt it will be very noticeable, as the amount of work done during the mutex-lock is extremely little.


_______________________________________________
varnish-misc mailing list
[email protected]
https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc

Reply via email to