816719 - Prevent session restores during Talos tests

Status: RESOLVED FIXED

(Firefox for Android Graveyard :: General, defect)

Description

[Brian Nicholson (:bnicholson)]

Looking at https://tbpl.mozilla.org/?tree=Try&rev=2e32d13eeebf, the failed rck test shows this in the log: "11-29 13:16:59.490 D/BRN     ( 2145): RESTORE!!". This is logged at https://hg.mozilla.org/try/rev/606a875cc58c#l1.27, which means we're doing a session restore.

For consistency between tests, we should avoid doing any session restores. According to gbrown, the rck test sets up a warm-up profile, then reuses that profile in the second run, so we should delete sessionstore.js between runs.

Comment 2

[Joel Maher ( :jmaher ) (UTC -8)]

is there a pref we can set to turn this off?  We probably encounter this on the mochitest robocop tests as well.

Comment 3

[Brian Nicholson (:bnicholson)]

The session restore is started in Java, so I don't know how we would pref it off.

Session restores are triggered by the existence of sessionstore.js, stored inside of the profile. Since we create a new profile for each test. I don't think this happens in most cases. gbrown said the rck tests are an exception because the same profile is used for multiple phases of the test...do other tests do the same thing?

Comment 4

[Joel Maher ( :jmaher ) (UTC -8)]

I was wrong in my previous comment about mochitest doing this.  For the mochitest rc run, we do create a fresh profile each time.  

This would affect all the talos based tests.  Is there a cost to generate sessionrestore.js?  I can make all the remote talos tests delete it after we initialize the browser and before we launch the test.

Comment 5

[Brian Nicholson (:bnicholson)]

> This would affect all the talos based tests.  Is there a cost to generate
> sessionrestore.js?

Nope - the session JSON is normally created from scratch at startup anyway. If anything, it's more costly to have sessionstore.js exist at startup since the previous session needs to be parsed and restored.

Comment 6

[Joel Maher ( :jmaher ) (UTC -8)]

Attachment: remove sessionstore.js before launching talos (1.0)

jhammel: can you review this with an eye to talos
gbrown: can you review it to sanity check I am removing the right file and comment if there are other files to delete  as well.

Comment 7

[Jeff Hammel]

Comment on attachment 687192 [details] [diff] [review]
remove sessionstore.js before launching talos (1.0)

Assuming that this doesn't err out if the file isn't there, r+

Comment 8

[Joel Maher ( :jmaher ) (UTC -8)]

devicemanager does not error out if the file doesn't exist.

waiting on gbrown and I can land ;)

Comment 9

[Geoff Brown [:gbrown] (pto Apr 11-18)]

Comment on attachment 687192 [details] [diff] [review]
remove sessionstore.js before launching talos (1.0)

Review of attachment 687192 [details] [diff] [review]:
-----------------------------------------------------------------

AFAIK, that is the only file that is giving us trouble. I think we want to keep other files (disk cache, startup cache, etc) for "historical reasons" if nothing else.

Comment 10

[Joel Maher ( :jmaher ) (UTC -8)]

we will be uploading a new talos.zip next week, if this is urgent we can deploy a new talos.zip with just this change sooner:
http://hg.mozilla.org/build/talos/rev/308e75e50c8c