1363464 - Warnings about the pref extensions.webextensions.uuids containing too much data

Status: UNCONFIRMED

(WebExtensions :: General, enhancement, P3)

Description

[Markus Stange [:mstange]]

In a WebExtensions test log I noticed the following warning message:

INFO - Console message: Warning: attempting to write 5667 bytes to preference extensions.webextensions.uuids. This is bad for general performance and memory usage. Such an amount of data should rather be written to an external file. This preference will not be sent to any content processes.

https://treeherder.mozilla.org/logviewer.html#?job_id=97191618&repo=autoland&lineNumber=3157

Is this going to cause problems? I'm a bit worried about the "This preference will not be sent to any content processes." part.

Comment 1

[Tom Ritter [:tjr]]

I don't know when/if extensions.webextensions.uuids gets read in subprocesses but the limit is 4KB right now and it seems like it wouldn't be to hard to install enough extensions to exceed this.

Comment 2

[Tom Ritter [:tjr]]

I didn't meant to resolve this; for a few minutes I thought the code had been removed.

Comment 3

[ISHIKAWA, Chiaki]

Hi,
I see the same warning lines during C-C TB's mochitest test suite run locally under Debian GNU/Linux.
The first few such warnings are as follows, and as of last count, I get 217 such warnings.
That is a bit too many, and I now wonder if the tests are properly executed as intended considering the nature of the message.

60:54.54 INFO Console message: Warning: attempting to write 4158 bytes to preference extensions.webextensions.uuids. This is bad for general performance and memory usage. Such an amount of data should rather be written to an external file. This preference will not be sent to any content processes.
60:58.00 INFO Console message: Warning: attempting to write 4238 bytes to preference extensions.webextensions.uuids. This is bad for general performance and memory usage. Such an amount of data should rather be written to an external file. This preference will not be sent to any content processes.
61:12.11 INFO Console message: Warning: attempting to write 4318 bytes to preference extensions.webextensions.uuids. This is bad for general performance and memory usage. Such an amount of data should rather be written to an external file. This preference will not be sent to any content processes.

Whatever the outcome is of debugging/fixing, it would be great to have the TB developers become aware of the issue if this may impact
TB test harness and specifically test program design.

TIA