Hi Varun,

Look at the recommendation for offheap_objects and memtable flush writers
and readers in the following guide
https://tobert.github.io/pages/als-cassandra-21-tuning-guide.html. In the
guide and cassandra.yaml the default is suggested as a good starting point.

If you want to use the default just omit the setting
of memtable_heap_space_in_mb instead of setting it to 0. Note in newer
versions of Cassandra setting the memtable_cleanup_threshold is deprecated.
The default value is said to be the only reasonable setting.

Regards,
Akhil


On Wed, May 24, 2017 at 1:41 PM, varun saluja <saluj...@gmail.com> wrote:

> Thanks Akhil for response.
>
> I have set memtable_allocation_type as Off-heap. But cassandra 2.1.x does
> not allow to set *memtable_heap_space_in_mb: 0.*
>
> It mentions , we need to assign some positive value to heap space. In such
> case, will memtable still use jvm heap space.
>
> Can anyone suggest below parameters.
>
> memtable_flush_writers:
> memtable_cleanup_threshold:
>
>
> PS : We have high write intensive workload . 5Node cluster (12 Core , 62GB
> RAM and flash disk per node)
>
>
> Regards,
> Varun Saluja
>
> On 23 May 2017 at 03:26, Akhil Mehra <akhilme...@gmail.com> wrote:
>
>> I believe off-heap storage was reintroduced in 3.4 (
>> https://issues.apache.org/jira/browse/CASSANDRA-9472). It was removed
>> from 3.0 due to the refactoring of the storage engine.  Check out
>> http://www.datastax.com/dev/blog/off-heap-memtables-in-Cassandra-2-1 to
>> get an overview of the pros and cons of using off-heap storage.
>>
>> Regards,
>> Akhil Mehra
>>
>>
>> On Tue, May 23, 2017 at 12:32 AM, varun saluja <saluj...@gmail.com>
>> wrote:
>>
>>> Hi Experts,
>>>
>>> I have some concerns regarding memtable parameters for my current
>>> version. 2.1.8.
>>>
>>> As per documentation , its mentioned to have Off-heap memtables in
>>> Cassandra 2.1 . And in releases 3.2.0 and 3.2.1, the only option that works
>>> is: heap-buffers.
>>> Can you Please suggest what value should be use for below paramteres in
>>> 2.1.x
>>> memtable_allocation_type :
>>>
>>> Regards,
>>> Varun Saluja
>>>
>>>
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>>
>

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