188850 - problem with MAX_NUMBER_OF_COOKIES under normal, prolonged, profile use

Status: RESOLVED FIXED

(Core :: Networking: Cookies, defect)

Description

[John Morrison]

I've mentioned this problem previously to morse and dwitte, but hadn't got
around to filing a bug about it.

Ever since 1994, Navigator has had a hard limit on the total number of cookies
allowed, MAX_NUMBER_OF_COOKIES, which is 300. Recently, I began noticing that
I was being logged out of sites (e.g., bugzilla) seemingly at random. After
investigating, I found the problem was this.

I have accumulated about 275 persistent cookies, with 3/4 of them having an
expiry date of 6 months to 30 years in the future, more than 95% with expiry
date of more than 14 days. So, when I start the browser, it doesn't take long
before a variety of session cookies get added to the list and I hit
MAX_NUMBER_OF_COOKIES (300).

The cookie code then goes to remove the oldest cookie, based on last access
time. But since I just started the browser, most have a last access time of 0,
and essentially the decision on which cookie to remove becomes a random
choice. And that is the reason for my "random" logouts.

dwitte mentioned an idea that came up when he met with darin about cookie stuff,
which was to write the cookies to disk in order of last access (and read them 
in, assigning a incremental time value as they are read in). That would seem to
be a good, short-term solution.

There may be a later decision to change the cookie format, but I'd like to leave
this bug for the simple, compatible solution (write out in order).

Comment 1

[Darin Fisher]

-> dwitte (figuring you might include this with your backend rewrite, or at
least it should probably be fixed after your patch lands.  feel free to send
this back to me.)

Comment 2

[[e-mail]]

Thanks for filing this one jrgm. darin, I can take this. I might need help
deciding whether to use your suggestion (writing cookies in order) or altering
the file format, I'll chat to you when I've looked at the problem more.

Comment 3

[Warner Young]

I'm not sure if this is the problem I'm seeing, but basically, every once in a
while, I find that I'm not logged in to bugzilla when I visit.  When I go to
look at the Cookie Manager, though, I can see all the bugzilla cookies are still
there, including the login cookie.  The cookie dates are all set for years in
the future.  It doesn't look like I have anywhere near 300 cookies, though.

Comment 4

[[e-mail]]

There are two limits - one is the total number of cookies, which is 300. The
other is the maximum number of cookies from one host, which is 20.

If you have less than 300 cookies, _and_ you have less than 20 cookies from
bugzilla.mozilla.org, then this isn't the problem you're seeing.

Comment 5

[[e-mail]]

*** Bug 187349 has been marked as a duplicate of this bug. ***

Comment 6

[[e-mail]]

marking reso/fixed per bug 195908.

Comment 7

[Michiel van Leeuwen (email: mvl+moz@)]

*** Bug 199603 has been marked as a duplicate of this bug. ***

Comment 8

[[e-mail]]

we can fix this in a more performant way if we ever change the fileformat. see
bug 230933.