G'day, I hope you are doing well.
Just wondering about ATS's support for RFC 5861 ( https://www.rfc-editor.org/rfc/rfc5861 ), specifically stale-while-revalidate. Based on our testing, our current config we have does NOT seem to allow serving stale while revalidating. There's an old doc from 2015 talking about the feature, but not sure if this was ever finalized. https://cwiki.apache.org/confluence/display/TS/Stale-While-Revalidate+in+the+core There is mention of stale-while-revalidate (SWR) here, but not a lot of details: https://docs.trafficserver.apache.org/admin-guide/plugins/collapsed_forwarding.en.html#description The cache architecture doesn't discuss serving stale while revalidate https://docs.trafficserver.apache.org/developer-guide/cache-architecture/architecture.en.html#cache-read Glossary term mentions revalidation, but nothing about stale. https://docs.trafficserver.apache.org/appendices/glossary.en.html#term-revalidation Looking at "is_stale_cache_response_returnable", it looks like the code does take into account must-revalidate header https://github.com/apache/trafficserver/blob/master/src/proxy/http/HttpTransact.cc#L5984 Grepping the code for these headers doesn't find anything. das@t:~/Downloads/trafficserver$ grep -R "stale-while-revalidate" ./ das@t:~/Downloads/trafficserver$ grep -R "stale-if-error" ./ So it seems like ATS does not support RFC 5861 -- Regards, Dave Seddon
