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From Cameron McKenzie <mckenzie....@gmail.com>
Subject Re: Creating PersistentEphemeralNode when noauth leads to cycle
Date Thu, 23 Jul 2015 21:58:04 GMT
hey Ausin,
All reasonable suggestions, I will have a think about it and see what we
can come up with. As far as parent nodes not existing, the
PersistentEphemeralNode recipe uses 'creatingParentsIfNecessary', so that's
not an issue.

It would just be a matter of detecting a NOAUTH error, then placing a watch
on the parent node and retrying whenever its state changed (either the auth
details change or the node itself gets deleted). We would still want to log
something I think, as I would say that in 99% of cases this is a user error.

I agree that tying the retry back to the policy is probably a good idea too.
cheers

On Fri, Jul 24, 2015 at 2:54 AM, Miller, Austin <
Austin.Miller@morganstanley.com> wrote:

>   Hi Cameron,
>
>
>
> Looking over the comments, the proposed change, to exit the loop by
> return, seems like a net negative.  While it prevents hammering the server,
> it seems to do so by violating the PEN contract, which I understood to be
> “If creating the node can eventually succeed, it will succeed.”  Now with
> the caveat that retry for auth issues is up to the user.
>
>
>
> The notion of using a watch on the parent node to wait for noauth to not
> be an issue seems to be much superior, because it would allow the contract
> to remain, eventually the PEN will succeed if it can succeed, while also
> not hammering the server.   I recognize the complexity would increase as
> the need for doing things in the right order to prevent race conditions
> would have to be properly thought through.
>
>
>
> What happens if the parent node doesn’t exist?
>
>
>
> Ultimately, could we tie failure back into the config retry somehow?  So
> that you can get exponential backoff retry behavior in PEN?
>
>
>
> Austin
>
>
>
> *From:* Cameron McKenzie [mailto:mckenzie.cam@gmail.com]
> *Sent:* Wednesday, July 22, 2015 7:40 PM
> *To:* dev@curator.apache.org
> *Cc:* Gupta, Abhishek (ICT); Miller, Austin (ICT)
> *Subject:* Re: Creating PersistentEphemeralNode when noauth leads to cycle
>
>
>
> This is definitely an issue, seems like it's the same problem as
> CURATOR-228. I can reproduce it, will look at a fix when I get a minute.
>
>
>
> On Wed, Jul 22, 2015 at 7:48 PM, Szekeres, Zoltan <
> Zoltan.Szekeres@morganstanley.com> wrote:
>
> Hi Curator Dev!
>
> We've encountered an issue when creating a PersistentEphemeralNode and the
> authentication fails for the given path. We received a NOAUTH result code,
> which the BackgroundCallback's processResult doesn't handle and tries to
> create the node again. This leads to a cycle. This is an issue for us,
> because it can generate thousands of requests per minute.
>
> We use curator 2.4.2 and zookeeper 3.4.6.
>
> A possibly related JIRA:
>
> https://issues.apache.org/jira/i#browse/CURATOR-228?jql=text%20~%20%22PersistentEphemeralNode%22
>
> Do you see this as an issue?
>
> Best Regards,
> Zoltan Szekeres
> Morgan Stanley | Institutional & Corporate Tech
> Lechner Odon fasor 8 | Floor 05
> Budapest, 1095
> Phone: +36 1 881-4657
> Zoltan.Szekeres@morganstanley.com<mailto:Zoltan.Szekeres@morganstanley.com
> >
>
>
>
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> NOTICE: Morgan Stanley is not acting as a municipal advisor and the
> opinions or views contained herein are not intended to be, and do not
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> Street Reform and Consumer Protection Act. If you have received this
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