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From Sean Busbey <bus...@apache.org>
Subject Re: HBase REST Client class appears not to be Thread Safe
Date Tue, 25 Sep 2018 14:47:15 GMT
Yep! Raise a JIRA describing the issue.

If you're up for fixing it leave a comment stating so and one of the JIRA
admins will make it so you can assign the ticket to yourself.

We fix things in the most recent branch impacted first; for this it'd be
master.

Thanks for pointing this issue out!



On Tue, Sep 25, 2018, 01:57 Jon Poulton <jsp1611@gmail.com> wrote:

> Hi there,
> Not that hard to make it thread safe to be honest. And given the older
> version of the client was thread safe, "principal of least surprise"
> suggests that it continue to be so. Apache Http Components is a nice
> library that is well understood, and it looks like its being used correctly
> elsewhere in the class. The instance variables are only used in a couple of
> places, and can be replaced with variables at the method level, which seems
> to have been done correctly in most methods. You could then explicitly
> state in the Javadoc that the client is intended to be thread safe.
>
> Would I raise a raise a ticket with your issue tracking system first? And
> which branch would this be fixed in? Apologies, I'm not really a regular
> open source contributor.
>
> Jon
>
> On Tue, 25 Sep 2018 at 04:50, Stack <stack@duboce.net> wrote:
>
> > Yeah, looks like it is not written thread-safe.
> >
> > As you suggest, we should note that at the least. You think it possible
> to
> > make it thread-safe Jon? Is it onerous running multiple clients or a pool
> > of clients?
> >
> > Thanks,
> > M
> >
> > On Mon, Sep 24, 2018 at 11:04 AM Jon Poulton <jsp1611@gmail.com> wrote:
> >
> > > I was looking at moving up to the 2.1 version of the HBase REST API and
> > was
> > > poking around the code base wondering how I set headers on a per
> request
> > > basis, when I noticed the the "Client" class at:
> > >
> > >
> >
> https://github.com/apache/hbase/blob/branch-2.1/hbase-rest/src/main/java/org/apache/hadoop/hbase/rest/client/Client.java
> > > appears to have HttpGet and HttpResponse instance variables (line 68
> and
> > > 69) that are not synchronised, nor do they have any kind of associated
> > > lock. The thread safety of the Client is undocumented, but usually
> Client
> > > classes can assumed to be thread safe.
> > >
> > > These instance variables are used further down in the class in
> > > unsynchronized blocks, meaning that were more than one thread to access
> > > methods that accessed the variables there is a potential race
> condition.
> > I
> > > was wondering if this is a known issue, a deliberate choice for some
> > > reason, or if the class is not supposed to be used in a multithreaded
> > > manner, and is intended to be used only within ThreadLocal?
> > >
> > > I checked in the master branch of the project and the issue appears to
> be
> > > present there also.
> > >
> > > Thanks
> > >
> > > Jon
> > >
> >
>

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