Apologies if I’m missing something, but doesn’t that page say that there is an option to have it treat freshness as such:
> Traffic Server considers all HTTP objects in the cache to be fresh: > Never revalidate HTTP objects in the cache with the origin server. By modifying proxy.config.http.cache.when_to_revalidate https://docs.trafficserver.apache.org/en/7.1.x/admin-guide/files/records.config.en.html#proxy-config-http-cache-when-to-revalidate Stephen > On Nov 23, 2017, at 09:26, Veiko Kukk <[email protected]> wrote: > > Now to think about it, i might have set dest_domain to wrong value. > Documentation is not that clear on that. If there are x.y.z.tld and a.b.z.tld > then what have to be written to dest_domain to capture both of those? > dest_domain=z.tld > or > dest_domain=*.*.z.tld > > Or someting else? > > Veiko > > > 2017-11-23 19:20 GMT+02:00 Veiko Kukk <[email protected]>: >> Hi Alan, >> >> That is what i had already done in cache.config: >> dest_domain=.*.source.tld ttl-in-cache=9999d >> >> Of cource, source.tld is actually real domain, and this did not avoid >> checking origin for object freshness, it was still considered stale by ATS. >> >> https://docs.trafficserver.apache.org/en/7.1.x/admin-guide/configuration/cache-basics.en.html#ensuring-cached-object-freshness >> describes that if Expires is present, it is used to calculate objects >> freshness. And there is no way to ignore it. I've configured now ATS to >> remove Expires header and set Cache-control: max-age=157784630 with header >> rewrite plugin and cond %{READ_RESPONSE_HDR_HOOK} >> Will see it that helps. >> >> Veiko >> >> >> 2017-11-23 18:38 GMT+02:00 Alan Carroll <[email protected]>: >>> You might try fiddling with the 'cache.config' file and set a cache TTL of >>> 10 years or so. >>> >>>> On Thu, Nov 23, 2017 at 10:11 AM, Veiko Kukk <[email protected]> wrote: >>>> Hi David, >>>> >>>> Objects are not fetched from ATS via browser. ATS is just internal cache. >>>> Only problem is to trick ATS into believing that object is always fresh, >>>> never stale. >>>> I wonder if modifying headers before ATS (READ_RESPONSE_HDR_HOOK) removing >>>> or changing Expires and/or adding max-age to some very big value might be >>>> right way to go for me. >>>> >>>> Veiko >>>> >>>> >>>> 2017-11-23 17:52 GMT+02:00 David Carlin <[email protected]>: >>>>> Have you considered adding "Cache-Control: Immutable" to these objects >>>>> which will never require re-validation? This will prevent the browser >>>>> from attempting an If-Modified-Since request. >>>>> >>>>> https://hacks.mozilla.org/2017/01/using-immutable-caching-to-speed-up-the-web/ >>>>> >>>>> David >>>>> >>>>>> On Thu, Nov 23, 2017 at 10:07 AM, Veiko Kukk <[email protected]> >>>>>> wrote: >>>>>> In addition to my previous e-mail, headers that are provided by source >>>>>> to ATS: >>>>>> >>>>>> < HTTP/1.1 200 OK >>>>>> < Content-Length: 1185954 >>>>>> < Accept-Ranges: bytes >>>>>> < Last-Modified: Mon, 02 Nov 2015 17:56:12 GMT >>>>>> < Etag: 92ef40097ba87bdf09efcf7e1cefd32a >>>>>> < X-Timestamp: 1446486971.39466 >>>>>> < Content-Type: application/octet-stream >>>>>> < Content-Disposition: attachment; >>>>>> filename="ABIYohNyPrJNjvFsAdgN5wc8D-8Yo4ZO.m4s"; >>>>>> filename*=UTF-8''ABIYohNyPrJNjvFsAdgN5wc8D-8Yo4ZO.m4s >>>>>> < Expires: Thu, 23 Nov 2017 15:27:30 GMT >>>>>> < X-Trans-Id: tx3a0af5473d5c41d38195c-005a16e30d >>>>>> < X-Openstack-Request-Id: tx3a0af5473d5c41d38195c-005a16e30d >>>>>> < Date: Thu, 23 Nov 2017 15:02:37 GMT >>>>>> < X-IPLB-Instance: 12631 >>>>>> >>>>>> I assume, Expires header is here to blame and must be overriden in ATS >>>>>> config, but how? I don't have control over source, its Openstack Swift >>>>>> object storage. >>>>>> >>>>>> Veiko >>>>>> >>>>>> >>>>>> 2017-11-23 16:35 GMT+02:00 Veiko Kukk <[email protected]>: >>>>>>> Hi, >>>>>>> >>>>>>> Could ATS in reverse proxy mode be configured such way that it would >>>>>>> never try to revalidate from source? It is known that in our case, >>>>>>> object never changes (and is never refetched from source) and it is >>>>>>> desirable to avoid any source validation. Validation verification adds >>>>>>> significant overhead and we need to avoid it. Response to client with >>>>>>> TCP_REFRESH_HIT would take 100-200ms instead of 0-10 in case of direct >>>>>>> local TCP_HIT. >>>>>>> >>>>>>> I've configured following: >>>>>>> dest_domain=.*.source.tld action=ignore-no-cache >>>>>>> dest_domain=.*.source.tld revalidate=9999d >>>>>>> dest_domain=.*.source.tld ttl-in-cache=9999d >>>>>>> >>>>>>> CONFIG proxy.config.http.cache.when_to_revalidate INT 3 >>>>>>> CONFIG proxy.config.http.cache.required_headers INT 0 >>>>>>> >>>>>>> But i still get TCP_REFRESH_HIT even when 9999 days have not passed >>>>>>> (obviously). >>>>>>> >>>>>>> NB! ATS is used as internal cache and our 'client' never explicitly >>>>>>> requests revalidation. >>>>>>> >>>>>>> Thanks, >>>>>>> Veiko >>>>>>> >>>>>> >>>>> >>>> >>> >> >
