Thank you for your response.

OK, I can try to do this. And for this experiment I should know a bit more 
about write operations in Ignite.

My question is about cache.putAll operation - does this operation make N write 
operations to thread pool instead of one (where N - map size in putAll 
argument)?

—
Evgeny Pryakhin

> 9 июля 2019 г., в 19:27, Ilya Kasnacheev <[email protected]> 
> написал(а):
> 
> Hello!
> 
> I don't think so. But I guess you may throttle on application side that 
> N(write operations) < N(stripes).
> 
> Regards,
> -- 
> Ilya Kasnacheev
> 
> 
> вт, 9 июл. 2019 г. в 19:16, Evgeny Pryakhin <[email protected] 
> <mailto:[email protected]>>:
> Thank you for your reply. I will check the thread pools. According to thread 
> pools description in ignite docs problem may be in Striped Pool.
> 
> In my case I have a lot of writes and a small number of reads.
> And in case while writes and reads processing through one queue i will have 
> this problem all the time.
> 
> If the problem in striped  pool, does there any way to split processing of 
> reads and writes into separate thread pools?
> 
> —
> Evgeny Pryakhin
> 
> 
>> 9 июля 2019 г., в 18:13, Ilya Kasnacheev <[email protected] 
>> <mailto:[email protected]>> написал(а):
>> 
>> Hello!
>> 
>> I think you should collect thread dumps from all nodes to locate the 
>> bottleneck. Then, maybe you need to adjust thread pool sizes.
>> 
>> My idea here is that some thread pool (stripe, probably) gets full with 
>> persistent cache writing operations, and reads have to wait in queue.
>> 
>> Regards,
>> -- 
>> Ilya Kasnacheev
>> 
>> 
>> вт, 9 июл. 2019 г. в 18:08, Evgeny Pryakhin <[email protected] 
>> <mailto:[email protected]>>:
>> Hello. I need some help or advise on my problem. 
>> 
>> Preface: 
>> - Ignite 2.5 (I have no options about upgrade to newer version) 
>> - cluster with 8 servers, 4 CPU and 64GB RAM each, HDD (not SSD). Operating 
>> system was tuned according to performance guide.
>> - two memory regions configured: one in-memory only (500MB) and one with 
>> persistence enabled (about 40GB memory). 
>> - one cache in in-memory region (about 300k records), backups - 3. Write 
>> mode: PRIMARY_SINC. 
>> - one cache in region with persistence (about 50M records), backups 3. Write 
>> mode: PRIMARY_SINC. 
>> - Ignite Thin Client as a driver. 
>> 
>> Scenario: 
>> - I have batch writes on first in memory cache - about 500/sec. 
>> Continuously. 
>> - I have a lot of reads on first in-memory cache - about 3k/sec. 
>> Continuously. 
>> - I have a lot of batch writes on second persistent cache. Batch size is 
>> about 1k records. Continuously. 
>> 
>> The Problem: 
>> - when I have batch writes to the second (persistent) cache disabled reads 
>> from first cache works well with small latency - <1ms. 
>> - when batch writes to persistent cache is turned on - reads from the first 
>> cache become very slow - about 200-300ms. 
>> 
>> I have no ideas how even to start investigation on this problem. May be I 
>> can check some metrics of cluster or system metrics on harware servers to 
>> find the right way to solve my problem. Do you have ant ideas about this?
> 

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