SystemTimer failing

Hello list,

I have searched everywhere else, tesed extensively and came to a point where I do not have a clue on what is happening.

I am using SystemTimer and Ruby/LDAP in my Rails application. Ruby/LDAP to authenticate against a LDAP server and SystemTimer in an effort to avoid potential long hangs.

Fact #1: SystemTimer works fine with the LDAP::Conn#bind method. It does cut at the right time if it fails. However, for some unknowing mystic reason, it just will not work with LDAP::Conn#search2.

The code I am using:

begin
arr = SystemTimer.timeout_after(5.seconds) do
connection.bind(self.bind_dn,self.password)
connection.search2(self.base_dn,1,"(& (userPassword=#{password}) (mail=#{email}))",nil,false,5,5000)
end
rescue Exception => e
msg = ‘LDAP server error.’
logger.error(logger_msg_template.call("#{msg} - Exception: #{e.message}"))
raise Timeout::Error.new(msg)
end

So, if bind takes more than 5 seconds, timeout will throw the correctly after 5 seconds. Good. If bind works, we then proceed to the search2 call. Things get sensitive here. If for any reason the search2 delays too much, the process is bound to just hang and wait for it’s return. Often it happens because the query is wrong (an attribute doesn’t exist in the LDAP entry, which might happen given the context of this code).

SystemTimer does throw the Timeout::Error (“time’s up!”), but it just doesn’t kill the Thread after the seconds specfied in the
timeout_after’s param. Check out this request that I just made:

ERROR: LDAP server error. - Exception: time’s up! - USER: marcelo@site.com, ACCOUNT: MyAccount, LDAP HOST: 89.150.80.164, PORT: 389.
SQL (0.3ms) ROLLBACK
Rendering template within layouts/application
Rendering directory/index
Completed in 34212ms (View: 19, DB: 7) | 200 OK [http://localhost/ldap]

Check the first line, it is from Rails’ logger. I also print the exception message, you can see that it was a “Time’s up!” (from SystemTimer), but look at how long it took: almost 35 seconds.

It is risky, since if many users are trying to setup a LDAP at the same time, our service could just hang completely.

I’m really lost and really need some enlightenment here, any suggestion appreciated!

Cheers,

Marcelo.

Forgot to include other relevant information:

Rails 2.3.5, SystemTimer 1.2, ruby-ldap 0.9.11 all on Mac OSX Snow Leopard.

Cheers,

Marcelo.

Hi Marcelo,

Not to avoid your specific SystemTimer and ldap timeout issue,
but .... Have you thought about trying the pure-ruby ldap lib
Net::LDAP (http://net-ldap.rubyforge.org/) instead of the c-based Ruby/
LDAP lib you're currently using (http://sourceforge.net/projects/ruby-
ldap/)?

I've always just used Net::LDAP whenever an app needed to auth against
and/or query an ldap db, and have never had any problems with timing
out un-responsive/too-long-running ldap connections using the regular
old ruby Timeout (http://ruby-doc.org/core/classes/Timeout.html). If
you can, I'd give Net::LDAP a chance to see if that doesn't solve your
problems.

Jeff

Thanks, Jeff. This could be an alternative. However, we are lucky that the SystemTimer is working fine on Ubuntu. It’s just failing on my local dev box (An OSX Snow Leopard one) and I’m intrigued…

Marcelo.

No, I can’t tell you. First, because it has nothing to do with the topic of this message, seconds, because it is obvious it is GoogleGroups, and it is simple enough to cancel the subscription, and third, because a simple google search is enough to get very clear instructions.

Gee, this list needs some moderation.

Marcelo.