markdibley has asked for the wisdom of the Perl Monks concerning the following question:

Hello

I need to maintain a sessionID that I receive from SalesForce when I login. The sessionID lasts for 15 minutes and then has to be renewed with a new login. However, I have multiple threads who all need to update SalesForce and if each of them login the login will cancel any current active sessionID.

I think this means that the best way to manage this is to either have a single thread responsible for issuing the current valid sessionID and renewing the sessionID when it becomes stale OR get each thread to read the sessionID from a file, test the date of the file to see if the sessionID is most likely to be stale, remove the file and generate a new one.

The problem I have with solution 1 is that I don't know how to get 2 threads to talk to each other. With solution 2 I am unhappy with the possibility that a thread can pick up a valid sessionID and then 1 second later another thread thinks it is going to be stale and resets it resulting in retries or complicated pausing rules.

I am sure this has been handled before, but my searches aren't being very productive. Is there a standard way of dealing with this problem? Or even better yet, a perl module that can handle it?

Thanks

  • Comment on Best method for maintaining a session ID across multiple threads

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Re: Best method for maintaining a session ID across multiple threads
by BrowserUk (Patriarch) on Jul 10, 2013 at 18:36 UTC
    The problem I have with solution 1 is that I don't know how to get 2 threads to talk to each other.

    If the "threads" in question are these threads, then have you not encountered threads::shared?

    If not, you'll need to specify/clarify your meaning of "threads".

    With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
    Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
    "Science is about questioning the status quo. Questioning authority".
    In the absence of evidence, opinion is indistinguishable from prejudice.
[reply]

      Hi, thanks for the reply

      I realised last night that I had missed out a couple of key factors to my problem. The first is that each "thread" is actually a queued job on a Gridengine cluster so each "thread" isn't forked from the program that does the logging in and also the cluster is across multiple servers which have a shared disk space and network but obviously don't have access to each others' processes.

      I guess I am using the term thread incorrectly

      So after more thought about it I am going to investigate writing something that can serve the sessionID to "processes" via a port. And when it comes to renewing the sessionID to perhaps look for, or enforce a 10 second window to ensure the last "customer" has time to finish it's connection.

      Unless, of course, there is a better way to do it.

[reply]
        I guess I am using the term thread incorrectly

        The generic term for a single instance in a cluster is 'node'.

        So after more thought about it I am going to investigate writing something that can serve the sessionID to "processes" via a port.

        Clustering software always has some form of message passing API that allows the processes to communicate.

        A quick google suggests that GridEngine supports OpenMPI. You shouldn't need to be inventing a solution for this, just read the docs.

        With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
        Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
        "Science is about questioning the status quo. Questioning authority".
        In the absence of evidence, opinion is indistinguishable from prejudice.
[reply]
[reply]
Re: Best method for maintaining a session ID across multiple threads
by Gangabass (Vicar) on Jul 11, 2013 at 03:32 UTC
    If you create your threads AFTER login when each thread will be logged in. 
    my $mech = WWW::Mechanize->new();
$mech->submit_form(
    with_fields => {
        login => "your_login",
        password => "your_password",
    },
);

my @threads =
  map { threads->create( \&create_thread, $_ ) }
  ( 1 .. $config->{number_of_threads} );

    [download]
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