thanks for the information. Posting the query too would be of help.
On Tue, Sep 22, 2015 at 11:56 AM, Jaydeep Chovatia <
chovatia.jayd...@gmail.com> wrote:
> Please find required details here:
>
> - Number of req/s
>
> 2k reads/s
>
> - Schema details
>
> create table test {
>
> a timeuuid,
>
> b bigint,
>
> c int,
>
> d int static,
>
> e int static,
>
> f int static,
>
> g int static,
>
> h int,
>
> i text,
>
> j text,
>
> k text,
>
> l text,
>
> m set<text>
>
> n bigint
>
> o bigint
>
> p bigint
>
> q bigint
>
> r int
>
> s text
>
> t bigint
>
> u text
>
> v text
>
> w text
>
> x bigint
>
> y bigint
>
> z bigint,
>
> primary key ((a, b), c)
>
> };
>
> - JVM settings about the heap
>
> Default settings
>
> - Execution time of the GC
>
> Avg. 400ms. I do not see long pauses of GC anywhere in the log file.
>
> On Tue, Sep 22, 2015 at 5:34 AM, Leleu Eric <eric.le...@worldline.com>
> wrote:
>
>> Hi,
>>
>>
>>
>>
>>
>> Before speaking about tuning, can you provide some additional information
>> ?
>>
>>
>>
>> - Number of req/s
>>
>> - Schema details
>>
>> - JVM settings about the heap
>>
>> - Execution time of the GC
>>
>>
>>
>> 43ms for a read latency may be acceptable according to the number of
>> request per second.
>>
>>
>>
>>
>>
>> Eric
>>
>>
>>
>> *De :* Jaydeep Chovatia [mailto:chovatia.jayd...@gmail.com]
>> *Envoyé :* mardi 22 septembre 2015 00:07
>> *À :* user@cassandra.apache.org
>> *Objet :* High read latency
>>
>>
>>
>> Hi,
>>
>>
>>
>> My application issues more read requests than write, I do see that under
>> load cfstats for one of the table is quite high around 43ms
>>
>>
>>
>> Local read count: 114479357
>>
>> Local read latency: 43.442 ms
>>
>> Local write count: 22288868
>>
>> Local write latency: 0.609 ms
>>
>>
>>
>>
>>
>> Here is my node configuration:
>>
>> RF=3, Read/Write with QUORUM, 64GB RAM, 48 CPU core. I have only 5 GB of
>> data on each node (and for experiment purpose I stored data in tmpfs)
>>
>>
>>
>> I've tried increasing concurrent_read count upto 512 but no help in read
>> latency. CPU/Memory/IO looks fine on system.
>>
>>
>>
>> Any idea what should I tune?
>>
>>
>>
>> Jaydeep
>>
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>
>
