Re: Bug#903155: #903155 tracker.debian.org is incredibly slow with certain cert9.db
On Sun, Jul 15, 2018 at 02:57:23AM +1000, Dmitry Smirnov wrote:
> Finally I've managed to isolate the problem.
> Removing "cert9.db" from profile folder relieves symptoms entirely.
>
> I could not reproduce the problem on new profile created on Firefox 61
> however I could easily reproduce on few computers around where profiles were
> upgraded from Firefox ESR.
>
> Structure of "cert9.db" is valid: it returns "ok" on "pragma
> integrity_check;" and re-creating it from its own ".dump" did not have any
> effect on the problem. I tried to remove records from "cert9.db" but could
> not track the problem to the particular record. It seems that slowness
> correlates with number of records in "nssPublic" table.
>
> ~~~~
> $ sqlite3 cert9.db
> select count(*) from nssPublic;
> 355
> ~~~~
>
> With only 355 rows, Firefox 61 cripples on "tracker.debian.org". I can't
> explain why only one particular site is affected so much. However what seems
> to amplify the problem is that we have "/home" (including Firefox profiles)
> on network file system.
sqlite doesn't work well on NFS. That's a long standing known issue. See
e.g. https://bugzilla.mozilla.org/show_bug.cgi?id=1432484 (comment 30
has a workaround)
> I'm attaching problematic "cert9.db". I've used it as reproducer with new
> Firefox profile: when copied into profile folder, opening [1] is
> significantly slower, it takes _minutes_ if profile is on network file system
> but opens reasonably fast if "cert9.db" is moved to tmpfs and symlinked back
> to profile folder.
>
> Once again, strangest thing is how much "tracker.debian.org" is affected
> comparing to pretty much any other site.
That's because tracker.debian.org, for some reason, asks for a
client-side SSL certificate.
Mike
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