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Zookeeper, mail # user - why does ZK ignore null pointer errors?


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Re: why does ZK ignore null pointer errors?
Brian Tarbox 2012-12-19, 12:38
Your guess is correct about failing while accepting.  We seem to
periodically find ourselves in a case where we disconnect (perhaps from
timing out the connection) and then somehow in the process of reconnecting
end up with dozens of connections or more and eventually hit
max-connections-per-client.  Needless to say it all falls apart at that
point.

Brian
On Wed, Dec 19, 2012 at 3:17 AM, Patrick Hunt <[EMAIL PROTECTED]> wrote:

> On Mon, Dec 17, 2012 at 5:44 AM, Brian Tarbox <[EMAIL PROTECTED]>
> wrote:
> > I'm trying to track down an issue where my zk cluster rolls over and I've
> > come across the main run loop in NIOServerCnxnFactory.java.
> >
> > I keep getting NullPointerError at line 190 which is:
> >
> > InetAddress ia = sc.socket().getInetAddress()
> >
> > but it is caught by a catch block at 217 that prints the message:
> > "Ignoring unexpected runtime exception".
> >
> > I'm of the school of thought that discourages ingnoring NPE!
> >
> > Can anyone enlighten me what the reasoning behind this code is?
> >
>
> While the server socket is open we try our best to accept connections
> regardless what happens on any one selector operation. Technically
> we're not ignoring, we're logging it and continuing/ignoring.
>
> I've only ever seen that line NPE in one case. It seemed to be related
> to the client connecting and failing (closing?) while the acceptor was
> in the process of accepting. Do you have any insight into what's
> happening in this case?
>
> Patrick
>

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