Created JIRA issue. Please do go through it. Not sure if community will
find this useful
https://issues.apache.org/jira/browse/BLUR-481

On Mon, Sep 5, 2016 at 9:50 PM, Aaron McCurry <[email protected]> wrote:

> Hey Ravi.  Not sure if you attached the patch on email or not.  The mail
> system removes attachments.  You can open an issue here:
>
> https://issues.apache.org/jira/browse/BLUR
>
> Or post it to a gist or if it really is small you can just include in an
> email.
>
> Thanks!
>
> Aaron
>
> On Tue, Aug 30, 2016 at 1:44 AM, Ravikumar Govindarajan <
> [email protected]> wrote:
>
> > PF the small patch we made for this. We had a specific requirement to
> > solve. Don't know how useful it will be for the community!
> >
> >
> >
> > On Thu, Aug 25, 2016 at 11:40 AM, Ravikumar Govindarajan <
> > [email protected]> wrote:
> >
> >> Sure, will share the patch in a couple of days...
> >>
> >> On Tue, Aug 23, 2016 at 9:18 PM, Aaron McCurry <[email protected]>
> >> wrote:
> >>
> >>> Cool, sounds good.  If you could send me the changes you have made that
> >>> would be great.  It would make it easier to integrate your changes back
> >>> into the project.  Thanks!
> >>>
> >>> Aaron
> >>>
> >>> On Wed, Aug 17, 2016 at 8:40 AM, Ravikumar Govindarajan <
> >>> [email protected]> wrote:
> >>>
> >>> > I removed _cacheValueQuietRefCannotBeReleased & instead directly
> used
> >>> a
> >>> > ByteArrayCacheValue every-time fillQuietly() is called.
> >>> >
> >>> > Now searches seem to work correctly. Not sure if it's because of
> >>> clone() or
> >>> > may be something else...
> >>> >
> >>> > FYI, I modified ByteArrayCacheValue to use a Store-Buffer to go easy
> >>> on gc
> >>> >
> >>> > On Wed, Aug 10, 2016 at 8:12 PM, Aaron McCurry <[email protected]>
> >>> wrote:
> >>> >
> >>> > > I'm not sure why that IOE is happening but if you want to change
> the
> >>> > quiet
> >>> > > behavior this is where you can control it.  There's a config and an
> >>> > object
> >>> > > there to change the behavior.
> >>> > >
> >>> > > https://github.com/apache/incubator-blur/blob/master/
> >>> > > blur-store/src/main/java/org/apache/blur/store/
> >>> > > BlockCacheDirectoryFactoryV2.java#L171
> >>> > >
> >>> > > On Wed, Aug 10, 2016 at 10:37 AM, Ravikumar Govindarajan <
> >>> > > [email protected]> wrote:
> >>> > >
> >>> > > > Aaron,
> >>> > > >
> >>> > > > Just one more help...
> >>> > > >
> >>> > > > I hardcoded _quiet=true in CacheIndexInput.java and started the
> >>> > > > shard-server. It seems to mangle the cached-bytes & results in
> >>> > > IOException
> >>> > > > during searches. Merges however work smoothly...
> >>> > > >
> >>> > > > I do know that _quiet is meant only for merge. But there is a
> >>> use-case
> >>> > I
> >>> > > am
> >>> > > > working on, which will need this setting during searches also...
> >>> > > >
> >>> > > > Any quick suggestions for this issue?
> >>> > > >
> >>> > > > --
> >>> > > > Ravi
> >>> > > >
> >>> > > > On Thu, Aug 4, 2016 at 2:43 PM, Aaron McCurry <
> [email protected]>
> >>> > > wrote:
> >>> > > >
> >>> > > > > Ok. Thanks!  I will patch the code and run some tests.
> >>> > > > >
> >>> > > > > On Monday, August 1, 2016, Ravikumar Govindarajan <
> >>> > > > > [email protected]> wrote:
> >>> > > > >
> >>> > > > > > We did a simple expiry check. Works fine as of now...
> >>> > > > > >
> >>> > > > > > private CacheValue lookup(boolean quietly) {
> >>> > > > > >
> >>> > > > > >     CacheValue cacheValue = _indexInputCache.get(_key.
> >>> > getBlockId());
> >>> > > > > >
> >>> > > > > >     if(cacheValue == null || *cacheValue.isExpired()*) {
> >>> > > > > >
> >>> > > > > >      ....
> >>> > > > > >
> >>> > > > > >     }
> >>> > > > > >
> >>> > > > > > }
> >>> > > > > >
> >>> > > > > > On Sun, Jul 31, 2016 at 2:14 AM, Aaron McCurry <
> >>> [email protected]
> >>> > > > > > <javascript:;>> wrote:
> >>> > > > > >
> >>> > > > > > > Ok I have to look into it.  Do you have a patch available?
> >>> > > > > > >
> >>> > > > > > > On Thu, Jul 28, 2016 at 4:47 AM, Ravikumar Govindarajan <
> >>> > > > > > > [email protected] <javascript:;>> wrote:
> >>> > > > > > >
> >>> > > > > > > > One issue we found in CacheIndexInput.java which is
> >>> causing NPE
> >>> > > > > > > >
> >>> > > > > > > >   private CacheValue lookup(boolean quietly) {
> >>> > > > > > > >
> >>> > > > > > > >     CacheValue cacheValue = _indexInputCache.get(_key.
> >>> > > > getBlockId());
> >>> > > > > > > >
> >>> > > > > > > >      .......
> >>> > > > > > > >
> >>> > > > > > > >      return cacheValue;
> >>> > > > > > > >
> >>> > > > > > > >      //There is no eviction check for the CacheValue
> >>> returned
> >>> > > from
> >>> > > > > > > > IndexInputCache, causing NPE
> >>> > > > > > > >
> >>> > > > > > > >   }
> >>> > > > > > > >
> >>> > > > > > > > Also, lookup method blindly adds to _indexInputCache
> before
> >>> > > > > returning.
> >>> > > > > > > > Instead, it would be better if it is done inside the
> >>> null-check
> >>> > > > > loop...
> >>> > > > > > > >
> >>> > > > > > > > On Fri, Jul 22, 2016 at 6:09 PM, Ravikumar Govindarajan <
> >>> > > > > > > > [email protected] <javascript:;>> wrote:
> >>> > > > > > > >
> >>> > > > > > > > > Thanks for the feedback Aaron
> >>> > > > > > > > >
> >>> > > > > > > > > On Thu, Jul 21, 2016 at 6:42 PM, Aaron McCurry <
> >>> > > > [email protected]
> >>> > > > > > <javascript:;>>
> >>> > > > > > > > wrote:
> >>> > > > > > > > >
> >>> > > > > > > > >> On Thu, Jul 21, 2016 at 1:55 AM, Ravikumar
> Govindarajan
> >>> <
> >>> > > > > > > > >> [email protected] <javascript:;>>
> wrote:
> >>> > > > > > > > >>
> >>> > > > > > > > >> > Just now saw BlockLocks code. It is documented to be
> >>> > > > > thread-safe.
> >>> > > > > > > > >> Apologize
> >>> > > > > > > > >> > for the trouble...
> >>> > > > > > > > >> >
> >>> > > > > > > > >> > Btw, a small nit. The below method is not returning
> >>> true.
> >>> > Is
> >>> > > > > that
> >>> > > > > > > > >> > intentional?
> >>> > > > > > > > >> >
> >>> > > > > > > > >> >     boolean releaseIfValid(long address) {
> >>> > > > > > > > >> >
> >>> > > > > > > > >> >       if (address >= _address && address <
> >>> _maxAddress) {
> >>> > > > > > > > >> >
> >>> > > > > > > > >> >         long offset = address - _address;
> >>> > > > > > > > >> >
> >>> > > > > > > > >> >         int index = (int) (offset / _chunkSize);
> >>> > > > > > > > >> >
> >>> > > > > > > > >> >         _locks.clear(index);
> >>> > > > > > > > >> >
> >>> > > > > > > > >> >       }
> >>> > > > > > > > >> >
> >>> > > > > > > > >> >       return false;
> >>> > > > > > > > >> >
> >>> > > > > > > > >> >     }
> >>> > > > > > > > >> >
> >>> > > > > > > > >>
> >>> > > > > > > > >> In my 30 second review I think you are right.  It
> should
> >>> > > > probably
> >>> > > > > > > return
> >>> > > > > > > > >> true.  However I want to alanyze what happens with the
> >>> > current
> >>> > > > > code
> >>> > > > > > > so I
> >>> > > > > > > > >> can write a test that proves there is a problem
> (because
> >>> > there
> >>> > > > > > > probably
> >>> > > > > > > > >> is)
> >>> > > > > > > > >> and fix it.
> >>> > > > > > > > >>
> >>> > > > > > > > >>
> >>> > > > > > > > >> >
> >>> > > > > > > > >> > Also, I thought a background thread can attempt
> >>> merging
> >>> > > > sparsely
> >>> > > > > > > > >> populated
> >>> > > > > > > > >> > slabs into one single slab & release free-mem (in
> >>> 128MB
> >>> > > > chunks)
> >>> > > > > > back
> >>> > > > > > > > to
> >>> > > > > > > > >> > OS...
> >>> > > > > > > > >> >
> >>> > > > > > > > >>
> >>> > > > > > > > >> I think this is a good idea, I just didn't get to
> >>> writing
> >>> > it.
> >>> > > > > > > > >>
> >>> > > > > > > > >>
> >>> > > > > > > > >> >
> >>> > > > > > > > >> > You think it could be beneficial or it would make it
> >>> > > > needlessly
> >>> > > > > > > > complex?
> >>> > > > > > > > >> >
> >>> > > > > > > > >>
> >>> > > > > > > > >> I think for dedicated servers is might be overkill,
> but
> >>> for
> >>> > a
> >>> > > > > mixed
> >>> > > > > > > > >> workload environment (think docker containers and the
> >>> like)
> >>> > it
> >>> > > > > would
> >>> > > > > > > be
> >>> > > > > > > > >> useful.
> >>> > > > > > > > >>
> >>> > > > > > > > >> Aaron
> >>> > > > > > > > >>
> >>> > > > > > > > >>
> >>> > > > > > > > >> >
> >>> > > > > > > > >> > On Wed, Jul 20, 2016 at 11:38 PM, Aaron McCurry <
> >>> > > > > > [email protected] <javascript:;>
> >>> > > > > > > >
> >>> > > > > > > > >> > wrote:
> >>> > > > > > > > >> >
> >>> > > > > > > > >> > > I don't think there is a race condition because
> the
> >>> > > > allocation
> >>> > > > > > > > occurs
> >>> > > > > > > > >> > > atomically in the BlockLocks class.  Do see a
> >>> problem?
> >>> > > Let
> >>> > > > me
> >>> > > > > > > know.
> >>> > > > > > > > >> > >
> >>> > > > > > > > >> > > Aaron
> >>> > > > > > > > >> > >
> >>> > > > > > > > >> > > On Wed, Jul 20, 2016 at 9:19 AM, Ravikumar
> >>> Govindarajan
> >>> > <
> >>> > > > > > > > >> > > [email protected] <javascript:;>>
> >>> wrote:
> >>> > > > > > > > >> > >
> >>> > > > > > > > >> > > > I came across the following in
> >>> > > > > > > > >> SlabAllocationCacheValueBufferPool.java.
> >>> > > > > > > > >> > > Is
> >>> > > > > > > > >> > > > the below method thread-safe?
> >>> > > > > > > > >> > > >
> >>> > > > > > > > >> > > >  @Override
> >>> > > > > > > > >> > > >
> >>> > > > > > > > >> > > >   public CacheValue getCacheValue(int
> >>> cacheBlockSize)
> >>> > {
> >>> > > > > > > > >> > > >
> >>> > > > > > > > >> > > >     validCacheBlockSize(cacheBlockSize);
> >>> > > > > > > > >> > > >
> >>> > > > > > > > >> > > >     int numberOfChunks = getNumberOfChunks(
> >>> > > > cacheBlockSize);
> >>> > > > > > > > >> > > >
> >>> > > > > > > > >> > > >     ...
> >>> > > > > > > > >> > > >
> >>> > > > > > > > >> > > >    }
> >>> > > > > > > > >> > > >
> >>> > > > > > > > >> > > >
> >>> > > > > > > > >> > > > It does allocation in a tight-loop using
> >>> BlockLocks,
> >>> > > Slab
> >>> > > > &
> >>> > > > > > > > Chunks.
> >>> > > > > > > > >> Is
> >>> > > > > > > > >> > > > there a race-condition where 2 threads can pick
> >>> same
> >>> > > slab
> >>> > > > &
> >>> > > > > > > chunk?
> >>> > > > > > > > >> > > >
> >>> > > > > > > > >> > >
> >>> > > > > > > > >> >
> >>> > > > > > > > >>
> >>> > > > > > > > >
> >>> > > > > > > > >
> >>> > > > > > > >
> >>> > > > > > >
> >>> > > > > >
> >>> > > > >
> >>> > > >
> >>> > >
> >>> >
> >>>
> >>
> >>
> >
>

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