Re: Semaphore waiting for permit even if node is shut down

[Valentin Kulichenko <va...@gmail.com>]

Vladislav,

I provided my thoughts in the ticket. Please take a look.

-Val

On Mon, Feb 29, 2016 at 8:46 AM, Vladisav Jelisavcic <vl...@gmail.com>
wrote:

> Sure, no problem.
>
> I created a ticket:
> https://issues.apache.org/jira/browse/IGNITE-2735
>
> and a PR to resolve this problem.
> I think this should also fix:  IGNITE-1977
> but the non-failover test scenario is not good anymore;
>
> Best regards,
> Vladisav
>
>
>
>
> On Mon, Feb 29, 2016 at 2:32 PM, Vladimir Ozerov <vo...@gridgain.com>
> wrote:
>
> > Hi,
> >
> > I tested your code in multi-node scenario, and semaphore is released fine
> > when node owning a permit has been closed. In your code sample there is
> > only one node, and in this case semaphore is not released. I think that
> > "acquire" method should throw an exception in this case (say,
> > InterruptedException) as semaphore is no longer accessible when node is
> > stopped.
> >
> > Vladislav,
> > I know you worked on distributed semaphore. Could you please share your
> > thoughts on the matter? And would you mind fixing that for a single-node
> > scenario?
> >
> > Vladimir.
> >
> > On Sun, Feb 28, 2016 at 11:14 PM, nyname00 <ma...@panagenda.com>
> > wrote:
> >
> > > Hi Igniters,
> > >
> > > I've got a problem with a semaphore that seems to wait for a permit
> even
> > if
> > > the node is already shut down. This behavior appears in a multi-node
> > setup
> > > where i try to shut down all nodes at the same time (using a
> > poison-pill).
> > > The code below can be used to reproduce the behavior. You will notice
> > that
> > > there is no call on sem1#release() - this is because in my poison-pill
> > > scenario there seems to be no way to get a handle to sem1. And since I
> > was
> > > under the impression that any semaphore gets released by Ignite when
> the
> > > node crashes/is shut down, I was expecting an exception on
> > sem2#acquire().
> > >
> > > Any ideas? Best regards,
> > > Mario
> > >
> > > public static void main(String[] args) {
> > >         Ignite i1 = Ignition.start(new
> > > IgniteConfiguration().setGridName("1"));
> > >
> > >         System.out.println(">>> I1 STARTED");
> > >         IgniteSemaphore sem1 = i1.semaphore("sem1", 1, true, true);
> > >         System.out.println(">>> S1 READ");
> > >         sem1.acquire();
> > >         System.out.println(">>> S1 ACQUIRED");
> > >
> > >         new Thread(() -> {
> > >             IgniteSemaphore sem2 = i1.semaphore("sem1", 1, true, true);
> > >             System.out.println(">>> S1 READ 2");
> > >             sem2.acquire();
> > >             try {
> > >                 System.out.println(">>> S1 ACQUIRED 2");
> > >             } finally {
> > >                 sem2.release();
> > >             }
> > >         }).start();
> > >
> > >         try {
> > >             TimeUnit.SECONDS.sleep(2);
> > >         } catch (InterruptedException e) {
> > >             e.printStackTrace();
> > >         }
> > >
> > >         System.out.println(">>> I1 CLOSING");
> > >         i1.close();
> > >         System.out.println(">>> I1 CLOSED");
> > >     }
> > >
> > >
> > >
> > > --
> > > View this message in context:
> > >
> >
> http://apache-ignite-users.70518.x6.nabble.com/Semaphore-waiting-for-permit-even-if-node-is-shut-down-tp3232.html
> > > Sent from the Apache Ignite Users mailing list archive at Nabble.com.
> > >
> >
>