ATS: Add the ability to check if origin server responses can be cached and their lifetime to the Lua plugin
Closed, ResolvedPublic
Actions

Assigned To

Authored By

	• ema
	Apr 30 2020, 3:50 PM

Description

We need to be able to (a) distinguish between cacheable and uncacheable responses in Lua, and (b) know the object lifetime as calculated by ATS. See for instance T250815. The proper methods are currently not implemented upstream, so we need to add them. This task tracks the progress of implementing the changes, getting them merged upstream, and backported to our packages.

I have opened https://github.com/apache/trafficserver/pull/6726 which takes care of (a) and https://github.com/apache/trafficserver/pull/6730 taking care of part of (b), namely adding the method to the trafficserver API. The same method will have to be exposed via tslua too.

Details

Project	Branch	Lines +/-	Subject
operations/puppet	production	+17 -11	ATS: cap TTL for cacheable 404 responses to 10 minutes
operations/debs/trafficserver	master	+194 -0	Release 8.0.7-1wm5
operations/puppet	production	+27 -0	ATS: add SystemTap probe for cacheable responses

Customize query in gerrit

Related Objects

Mentioned In: T249335: Memory leak on ats-tls 8.0.6
Mentioned Here: T249335: Memory leak on ats-tls 8.0.6
T250815: HTTP 400 Error when trying to save an edit on English Wikipedia: Error contacting the Parsoid/RESTBase server

Event Timeline

• ema created this task.Apr 30 2020, 3:50 PM

Restricted Application added a project: SRE. · View Herald TranscriptApr 30 2020, 3:50 PM

Restricted Application added a subscriber: Aklapper. · View Herald Transcript

• ema updated the task description. (Show Details)Apr 30 2020, 3:50 PM

Change 593735 had a related patch set uploaded (by Ema; owner: Ema):
[operations/puppet@production] ATS: add SystemTap probe for cacheable responses

https://gerrit.wikimedia.org/r/593735

gerritbot added a project: Patch-For-Review.May 1 2020, 10:42 AM

Change 593735 merged by Ema:
[operations/puppet@production] ATS: add SystemTap probe for cacheable responses

https://gerrit.wikimedia.org/r/593735

• ema triaged this task as Medium priority.May 4 2020, 4:08 PM

• ema updated the task description. (Show Details)

• ema moved this task from Backlog to Caching on the Traffic board.May 7 2020, 2:52 PM

The PR adding a function to the TS API for getting maxage was merged yesterday. Now it just needs to be made accessible via tslua, then we're done: https://github.com/apache/trafficserver/pull/6767

Change 596160 had a related patch set uploaded (by Ema; owner: Ema):
[operations/debs/trafficserver@master] Backport patches adding ts.server_response.get_maxage()

https://gerrit.wikimedia.org/r/596160

Change 596160 merged by Ema:
[operations/debs/trafficserver@master] Release 8.0.7-1wm5

https://gerrit.wikimedia.org/r/596160

Mentioned in SAL (#wikimedia-operations) [2020-05-13T14:35:19Z] <vgutierrez> upload trafficserver 8.0.7-1wm6 to apt.wm.o (buster) - T249335 T251537

Stashbot mentioned this in T249335: Memory leak on ats-tls 8.0.6.May 13 2020, 2:35 PM

Change 595877 had a related patch set uploaded (by Ema; owner: Ema):
[operations/puppet@production] ATS: cap TTL for cacheable 404 responses to 10 minutes

https://gerrit.wikimedia.org/r/595877

In T251537#6132201, @ema wrote:

https://github.com/apache/trafficserver/pull/6767

That's been merged upstream too and backported to our packages in 8.0.7-1wm5.

Change 595877 merged by Ema:
[operations/puppet@production] ATS: cap TTL for cacheable 404 responses to 10 minutes