[infinispan-dev] still to do on HR-embedded integration in ISPN-2281

Wed May 29 09:26:31 EDT 2013

On May 29, 2013, at 2:17 PM, Dan Berindei <dan.berindei at gmail.com> wrote:

> 
> Cheers
> Dan
> 
> 
> 
> On Tue, May 28, 2013 at 4:20 PM, Galder Zamarreño <galder at redhat.com> wrote:
> Basically, the difference between Hot Rod then and now is: 32 bytes, which is: new metadata object, a reference to it, and 2 unusued longs for immortal entries.
> 
> With embedded metadata (~191 bytes per entry): https://dl.dropboxusercontent.com/u/6148072/with-embedded.png
> With versioned entries (~159 bytes per entry): https://dl.dropboxusercontent.com/u/6148072/with-versioned.png
> 
> And there's more: we have internal cache entries that have a reference to internal cache values, per entry. This is useful for some cases (cache stores…etc), but this extra reference to the value, plus the value object itself, is 16 bytes (how useful is it really to have a separate value instance to keep just the value? Needs reassessing its usefulness...).
> 
> 
> +1 to remove InternalCacheValue (I thought about storing InternalCacheValues directly in the DataContainer, but it would probably create too much garbage to create InternalCacheEntries all the time).

Interesting point… I think ICEs are used way more than ICVs, which yeah, would generate a lot of garbage creating them all the time. I'll investigate this just in case.

> 
>  
> So really, I think the minimum Hot Rod overhead we should aim for is ~143 bytes. If each server module could define what the ICE class (well, classes to cover all immortal, mortal…etc cases) to use, which is purely designed for their servers (i.e. hot rod just needs: value + version; memcached needs: value + version + flags), we could get to this level…
> 
> 
> You mean embed the metadata fields directly in the ICE? Wouldn't that get us back to what we had before introducing the Metadata interface?

Nope. Users can still provide metadata and that would be stored in a MetadatICE instance, with some extra cost. However, for our own internal use cases for metadata (hotrod, memcached, rest), we can optimise things further with what I said: having endpoint specific ICE/Vs that are stored directly, saving memory compare to what we had before (at least 16 bytes per entry).

>  
> You still want the metadata to be passed from the client, but for those specialised use cases in Infinispan, we could have a mapping between the metadata type and the type of ICEs created…
> 
> 
> If HotRod knows it always needs a ServerEntryVersion, it could implement EntryVersion directly in HotRodMetadata implementation that implements EntryVersion directly (version() returns this). This could even be combined with your idea, so we could have a HotRodInternalCacheEntry that implements InternalCacheEntry, Metadata, and EntryVersion :)

^ Hmmm, interesting propect. If the metadata passed is also an ICE, it could just take it… but there's the matter or mortal/immortal/transient entries to deal with too. 

> 
>  
> If anyone has any other ideas, shout now! :)
> 
> Cheers,
> 
> On May 28, 2013, at 3:07 PM, Galder Zamarreño <galder at redhat.com> wrote:
> 
> > All, I've managed to replicate this locally and I'm now looking at the heap dumps.
> >
> > Cheers,
> >
> > On May 27, 2013, at 5:34 PM, Galder Zamarreño <galder at redhat.com> wrote:
> >
> >> Hmmmm, not the expected results. There's no way we should be consuming more memory per entry. It should definitely be less, particularly for Hot Rod and Memcached and about the same for REST. The fact that all of them grow seems to be there's an issue in the core impl.
> >>
> >> @Martin, can you generate a heap dump, say for Hot Rod (with 512b entries) at the end of the test (when the cache is still populated)?
> >>
> >> Cheers,
> >>
> >> On May 24, 2013, at 2:50 PM, Martin Gencur <mgencur at redhat.com> wrote:
> >>
> >>> Hi,
> >>> so I gave it another try with latest Infinispan and Infinispan-server snapshots (HEAD: a901168, resp. bc432fa) . In short, the results are still the same for inVM mode but worse for client-server mode. Of course, I haven't changed anything in the test since last time.
> >>>
> >>> This time, I left out the results for 1MB entries because there's high distortion due to the low number of entries stored in a cache       (storing 100MB of data). Previously, the results looked better for HotRod compared to the first round of tests I did for ISPN 5.2. Now the results for HotRod are worst of the three measurements, inVM mode remains the same:
> >>>
> >>> HotRod (ISPN 5.2):
> >>> entry size -> overhead per entry
> >>> 512B  -> 174B
> >>> 1kB   -> 178B
> >>> 10kB  -> 176B
> >>>
> >>> HotRod (ISPN 5.3-SNAPSHOT, a few weeks ago)
> >>> 512B  -> 159 (~ -9%)
> >>> 1kB   -> 159 (~ -11%)
> >>> 10kB  -> 154 (this is perhaps affected by the low number of entries stored in mem.)
> >>>
> >>> HotRod (ISPN 5.3-SNAPSHOT, now)
> >>> 512B  -> 191
> >>> 1kB   -> 191 (measured twice)
> >>> 10kB  -> 186 (looks a bit distorted already)
> >>>
> >>> ------------------------
> >>>
> >>> Memcached (ISPN 5.2)
> >>> 512B  -> 184
> >>> 1kB   -> 181
> >>> 10kB  -> 182
> >>>
> >>> Memcached (ISPN 5.3-SNAPSHOT)
> >>> 512   -> 228
> >>> 1kB   -> 227
> >>> 10kB  -> 235
> >>>
> >>> --------------------------------
> >>>
> >>> REST (ISPN 5.2)
> >>> 512B  -> 208
> >>> 1kB   -> 205
> >>> 10kB  -> 206
> >>>
> >>> REST (ISPN 5.3-SNAPSHOT)
> >>> 512   -> 247
> >>> 1kB   -> 247
> >>> 10kB  -> 251
> >>>
> >>> ------------------------------------
> >>>
> >>> inVM (ISPN 5.2)
> >>> 512B  -> 151
> >>> 1kB   -> 151
> >>> 10kB  -> 155
> >>>
> >>> inVM (ISPN 5.3-SNAPSHOT)
> >>> 512   -> 150
> >>> 1kB   -> 150
> >>> 10kB  -> 150
> >>>
> >>>
> >>> Martin
> >>>
> >>>
> >>> Dne 23.5.2013 18:13, Mircea Markus napsal(a):
> >>>> Hi Martin,
> >>>>
> >>>> Galder has finalised the remaining bits of ISPN-2281. Is it possible for you to re-run the test to see where we are with the memory consumption?
> >>>>
> >>>> On 13 May 2013, at 10:44, Galder Zamarreño
> >>>> <galder at redhat.com>
> >>>> wrote:
> >>>>
> >>>>
> >>>>>> On May 7, 2013, at 4:55 PM, Manik Surtani <msurtani at redhat.com>
> >>>>>> wrote:
> >>>>>>
> >>>>>>
> >>>>>>> On 7 May 2013, at 15:39, Martin Gencur <mgencur at redhat.com>
> >>>>>>> wrote:
> >>>>>>>
> >>>>>>>
> >>>>>>>> I can make a blog post once we have this for Memcached and REST. I guess it is not ready yet.
> >>>>>>>>
> >>>>>>> Yes please.  Nice work.  :)
> >>>>>>>
> >>>> Cheers,
> >>>>
> >>>
> >>> _______________________________________________
> >>> infinispan-dev mailing list
> >>> infinispan-dev at lists.jboss.org
> >>> https://lists.jboss.org/mailman/listinfo/infinispan-dev
> >>
> >>
> >> --
> >> Galder Zamarreño
> >> galder at redhat.com
> >> twitter.com/galderz
> >>
> >> Project Lead, Escalante
> >> http://escalante.io
> >>
> >> Engineer, Infinispan
> >> http://infinispan.org
> >>
> >>
> >> _______________________________________________
> >> infinispan-dev mailing list
> >> infinispan-dev at lists.jboss.org
> >> https://lists.jboss.org/mailman/listinfo/infinispan-dev
> >
> >
> > --
> > Galder Zamarreño
> > galder at redhat.com
> > twitter.com/galderz
> >
> > Project Lead, Escalante
> > http://escalante.io
> >
> > Engineer, Infinispan
> > http://infinispan.org
> >
> >
> > _______________________________________________
> > infinispan-dev mailing list
> > infinispan-dev at lists.jboss.org
> > https://lists.jboss.org/mailman/listinfo/infinispan-dev
> 
> 
> --
> Galder Zamarreño
> galder at redhat.com
> twitter.com/galderz
> 
> Project Lead, Escalante
> http://escalante.io
> 
> Engineer, Infinispan
> http://infinispan.org
> 
> 
> _______________________________________________
> infinispan-dev mailing list
> infinispan-dev at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/infinispan-dev
> 
> _______________________________________________
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--
Galder Zamarreño
galder at redhat.com
twitter.com/galderz

Project Lead, Escalante
http://escalante.io

Engineer, Infinispan
http://infinispan.org