The hive semantic analyzer is not fully thread safe. We'd like to remove
that lock but it will be a large project.
Brock
On Thu, Aug 15, 2013 at 11:12 AM, Kristopher Glover <kglo...@appnexus.com>wrote:
> Hi Everyone,
>
> I'm experiencing a threading issue with the Hive client where I want to
> run multiple queries on the same JVM.
>
> The problem I'm having is that org.apache.hadoop.hive.ql.Driver#run (line
> 907) has the following few lines of code :
>
> synchronized (compileMonitor) {
>
> ret = compile(command);
>
> }
>
>
> The compileMonitor is a static so it blocks all threads even though I'm
> using different instances of the Driver class. I could explicitly call
> Driver#compile then Driver#execute to avoid the synchronized block but I
> don't know if it's serving a special purpose. Does anyone know why that
> synchronized block is there and if its really necessary ?
>
>
> Thanks,
>
> Kris
>
--
Apache MRUnit - Unit testing MapReduce - http://mrunit.apache.org
