Beefy Boxes and Bandwidth Generously Provided by pair Networks
There's more than one way to do things

Re^6: Perl 5.8.8 threads, clean exit

by T_I (Novice)
on Feb 27, 2013 at 14:26 UTC ( #1020897=note: print w/replies, xml ) Need Help??

in reply to Re^5: Perl 5.8.8 threads, clean exit
in thread Perl 5.8.8 threads, clean exit

What I want to do is the following (in wierd prototype):

main: our %ssh (hash of active ssh sessions, Net::OpenSSH) read file with list of vm's to turn off. for each line with 1 or more vm's start thread1 kill_all_thread1 after timeout for each line with 1 or more vm's start thread2 thread1: @vms = split (',',$0) for each vm gather all info needed if (! exists $ssh{vm-manager} { $ssh{vm-manager} = Net::OpenSSH->new(vm-manager) (stdout,stderr)=$ssh{vm-manager}->capture2(request vm to stop) *check errors* (status,stderr)=$ssh{vm-manager}->capture2(request status vm) while (status != dead) { (status,stderr)=$ssh{vm-manager}->capture2(request status + vm) sleep some time } thread2: @vms = split (',',$0) for each vm gather all info needed if (! exists $ssh{vm-manager} { $ssh{vm-manager} = Net::OpenSSH->new(vm-manager) (stdout,stderr)=$ssh{vm-manager}->capture2(pull plug vm)

The current solution with ksh has several problems:

  • It's all sequential.
    Not a problem with 2-3 vm's, but the total we have is 70+.
  • It initiates a new ssh session per command issued.
    When trying to split the list into seperate commands, the vm-manager gets swamped with ssh sessions. (old hardware, no budget to replace with something fast enough to handle lots of ssh logins)
  • Most vms can be stopped parallel, but some combination of vms may only be stopped in sequence. (application requirements)
  • Sometimes a vm refuses to die within the allotted time.
  • When a vm refuses to die and there are dependent vms, the nice version has to be killed and the rude version has to be started for the same set.
    I.e. in list lpar1,lpar2 when lpar1 refuses to die, it's not allowed to stop lpar2 and then kill lpar1, but it's required to kill lpar1 and then stop/kill lpar2.

Now I'm typing this, I'm thinking of relocating the timeout inside the while loop of thread1, combine thread 1 and 2 and have the resulting thread handle the stopping of it's list. When a timeout within the thread occurs, kill and be friendly with the next. (or surrender after second timeout and exit with a list of vms that have not yet been disabled.)

With the scenario above, is it possible to have a second timeout in main and just simply exit when the main timeout is reached?

$_->join for @jobs;

This waits for the threads to end, how to escape this line? As far as I can find, that's where I need the signal (and the threads->exit() in the signal handler) for.

Replies are listed 'Best First'.
Re^7: Perl 5.8.8 threads, clean exit
by BrowserUk (Pope) on Feb 27, 2013 at 15:22 UTC

    Is there a question in there?

    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.

Log In?

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://1020897]
and all is quiet...

How do I use this? | Other CB clients
Other Users?
Others avoiding work at the Monastery: (5)
As of 2018-05-26 22:32 GMT
Find Nodes?
    Voting Booth?