Comments on: FastSessions Rails Plugin Released

By: Andrew Watkins

Andrew Watkins — Fri, 19 Mar 2010 02:17:00 +0000

We’re using postgresql and actually ported it over, except for one problem: Postgresql does have crc32 as a function. You can kind of get there by either writing your own or installing the one with ltree. Postgresql does however have md5. What we did is setup tests against unique(md5_session_string, session_id), unique(crc32, session_id), and unique(md5_session_byte,session_id). The last one is a byte representation of the md5 hash. For random queries, the 1st two implementations ran at about the same speed, which was basically instantaneous. The byte one definitely showed a little lag, and so would not recommend it. Finally we created a stored procedure to actually handle the insert/update as postgresql doesn’t have a “ON DUPLICATE KEY UPDATE”. The question is whether or not this is faster than just indexing the session_id itself or is something screwy is going on where postgresql is optimizing against the hashed values.

By: Paolo Montrasio

Paolo Montrasio — Fri, 19 Mar 2010 10:51:00 +0000

There is a plugin called SmartSessionStore that does more or less the same and works also with PostgreSQL. I’ve been using it for almost an year in production with no problems at all.

By: Eric

Eric — Fri, 19 Mar 2010 17:22:00 +0000

What would the impact be for using fast_sessions with MySQL and MyISAM tables as opposed to InnoDB (table vs. row level locking)? Any thoughts?

By: Eric

Eric — Fri, 19 Mar 2010 20:39:00 +0000

What about using MyISAM for the sessions table. Implications, like for instance, table locking during updates/additions?
Unfortunately, my MySQL database was not compiled with InnoDB.

By: Andrey

Andrey — Fri, 19 Mar 2010 10:31:00 +0000

Of course, it’s a little bit artificial case, but when session size exceed 70kb I become error (code 500). Log says that sql connection lost during update operation.
After that application don’t get back alive, until I delete session record.

By: Interesting Rails Tidbits #4

Interesting Rails Tidbits #4 — Fri, 19 Mar 2010 21:30:00 +0000

[...] FastSessions (official project page) is a Rails plugin that performs some interesting tricks on the way that Rails handles session storage. It appears only to work on MySQL and no hard performance numbers are given yet (though a “10-15% performance gain” is suggested), but I’ve seen quite a few people linking to it, so it might be worth a look. Scribd.com (YouTube-for-PDFs) supposedly uses this in production. [...]

By: Drew Blas

Drew Blas — Fri, 19 Mar 2010 15:42:00 +0000

You mentioned turning off sessions from bot requests, but didn’t mention how. Here’s my method:

[application.rb]
# turn off sessions if this is a request from a robot
session ff, :if => proc { |request| request.user_agentuser_agent =~ /\b(Baidu|Gigabot|Googlebot|libwww-perl|lwp-trivial|msnbot|SiteUptime|Slurp|WordPress|ZIBB|ZyBorg)\b/i }

By: Matthias

Matthias — Fri, 19 Mar 2010 12:21:00 +0000

< UNIX_TIMESTAMP(NOW()) – #{seconds}”

Note the UNIX_TIMESTAMP around (updated_at) in first part of the comment

By: Matthias

Matthias — Fri, 19 Mar 2010 12:19:00 +0000

the self.delete_old! method did not work for me. I changed it to:

@@connection.execute “DELETE FROM #{table_name} WHERE UNIX_TIMESTAMP(updated_at)

By: Chris

Chris — Fri, 19 Mar 2010 05:51:00 +0000

Why don’t you just use the cookiestore in rails 2.0? That way you don’t need to store sessions in the database at all!