ignite-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Denis Mekhanikov <dmekhani...@gmail.com>
Subject Re: SortedEvictionPolicy doesn't work as expected
Date Wed, 28 Feb 2018 21:22:39 GMT

If you access some records, that are stored in the off-heap memory, then
you have to wait, while Ignite is deserializing the data and copying it to
Java heap.
But if the needed entry is already available in Java heap, Ignite doesn't
have to perform these steps to return the result, it can just give you what
it already has.
So, the idea behind a Java heap cache is to make access to some specific
entries faster. The entries, that are kept on the heap will be accessed way
faster, than the once, that are stored in off-heap memory.

Note, that all of this is true only for the local records. If you have
multiple nodes, and you do a lot of cross-node reads, then Java heap cache
won't help you much.


ср, 28 февр. 2018 г. в 20:41, mamaco <mamaco@163.com>:

> Hi Denis,
> Thank you for the response, I appreciate it.
> Yes, I agree with you, it could be done by various solutions, 'REST',
> 'Event Listener' or any standalone instance.
> According to the new design you mentioned, ignite stop the support of '
> *setMemoryMode(CacheMemoryMode.ONHEAP_TIERED)*' use Off-Heap in default
> and force a switch setOnheapCacheEnabled in 2.0.0+ version, however, if we
> can't get the entries straight from on-heap, what do on-heap policies stand
> for (sort/fifo/random). Because no matter what we do, it returns the whole
> thing. or the goal is just to make a faster cache? I don't mean to be
> negative, I'm just curious about the truth under the hood.
> Marco
> ------------------------------
> Sent from the Apache Ignite Users mailing list archive
> <http://apache-ignite-users.70518.x6.nabble.com/> at Nabble.com.

View raw message