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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