Dmitriy,
There will be no performance overhead for reads, but there will be a
significant performance overhead for writes because each update must be
changed in offheap, and since the offheap will be very small, there will be
a lot of pages reads and spills.
2017-11-15 6:53 GMT+03:00 Dmitriy Setrakyan <
[hidden email]>:
> Igniters,
>
> I am noticing that some users struggle with performance when using
> collocated compute and off-heap cache. The main reason is that collocated
> computations access data locally, directly on the server, and with off-heap
> cache all binary objects need to be deserialized for every access.
>
> A much more efficient approach is to enable on-heap cache, so the data is
> deserialized once and then stored in the on-heap cache. However, the
> disadvantage of this approach is that the data foot print in memory doubles
> because the data is now stores in both, on-heap and off-heap caches.
>
> What if we suggested the following configuration for the collocated compute
> users:
>
> - enable the *on-heap cache* and make it large enough to fit all the
> data
> - enable *Ignite native persistence* in BACKGROUND mode, so there is no
> performance overhead for persisting data
> - make *off-heap cache* very small compared to the on-heap cache.
>
> This way, the memory will be consumed by the on-heap cache mostly, the data
> will be cached in deserialized form, and there should be no performance
> degradation.
>
> Will this approach work?
>
> D.
>
Locked
