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From Jack Krupansky <jack.krupan...@gmail.com>
Subject Re: Are Triggers in Cassandra 2.1.2 performace Hog??
Date Wed, 07 Jan 2015 20:55:15 GMT
DSE does now have a queue to decouple Cassandra insert and Solr indexing.
It will block only when/if the queue is filled - you can configure the size
of the queue. So, to be clear, DSE no longer has the highlighted problem
mentioned for ES.

-- Jack Krupansky

On Wed, Jan 7, 2015 at 9:46 AM, Ken Hancock <ken.hancock@schange.com> wrote:

> When last I looked at Datastax Enterprise (DSE 3.0ish), it exhibits the
> same problem that you highlight, no different than your good idea of
> asynchronously pushing to ES.
>
> Each Cassandra write was indexed independently by each server in the
> replication group.  If a node timed out or a mutation was dropped, that
> Solr node would have an out-of-sync index.  Doing a solr query such as
> count(*) users could return inconsistent results depending on which node
> you hit since solr didn't support Cassandra consistency levels.
>
> I haven't seen any blog posts or docs as to whether this intrinsic
> mismatch between how Cassandra handles eventual consistency and Solr has
> ever been resolved.
>
> Ken
>
>
> On Wed, Jan 7, 2015 at 9:05 AM, DuyHai Doan <doanduyhai@gmail.com> wrote:
>
>> Be very very careful not to perform blocking calls to ElasticSearch in
>> your trigger otherwise you will kill C* performance. The biggest danger of
>> the triggers in their current state is that they are on the write path.
>>
>> In your trigger, you can try to push the mutation asynchronously to ES
>> but in this case it will mean managing a thread pool and all related issues.
>>
>> Not even mentioning atomicity issues like: what happen if the update to
>> ES fails  or the connection times out ? etc ...
>>
>> As an alternative, instead of implementing yourself the integration with
>> ES, you can have a look at Datastax Enterprise integration of Cassandra
>> with Apache Solr (not free) or some open-source alternatives like Stratio
>> or TupleJump fork of Cassandra with Lucene integration.
>>
>> On Wed, Jan 7, 2015 at 2:40 PM, Asit KAUSHIK <asitkaushiknosql@gmail.com>
>> wrote:
>>
>>> HI All,
>>>
>>> We are trying to integrate elasticsearch with Cassandra and as the river
>>> plugin uses select * from any table it seems to be bad performance choice.
>>> So i was thinking of inserting into elasticsearch using Cassandra trigger.
>>> So i wanted your view does a Cassandra Trigger impacts the performance
>>> of read/Write of Cassandra.
>>>
>>> Also any other way you guys achieve this please guide me. I am struck on
>>> this .
>>>
>>> Regards
>>> Asit
>>>
>>>
>>
>
>
>
>

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