* ] Re: writing speed test
: Wed, 2 Jun 2010 10:44:52 +0200
Since this thread has now gone on for a while...
As far as I can tell you never specify the characteristics of your
writes. Evaluating expected write throughput in terms of "MB/s to
disk" is pretty impossible if one does n
Since this thread has now gone on for a while...
As far as I can tell you never specify the characteristics of your
writes. Evaluating expected write throughput in terms of "MB/s to
disk" is pretty impossible if one does not know anything about the
nature of the writes. If you're expecting 50 MB,
Still seems MEM.
However it's hard to convince that constantly writing(even great amount
of data) needs so much MEM(16GB). The process is quite simple,
input_data -> memtable -> flush to disk
right? What does cassandra need so much MEM for?
Thanks!
?? 2010-06-02 16:24 +0800??lwl??
> N
Hi,
I tried,
1-consistency level ZERO
2-JVM heap 4GB
3-normal Memtable cache
and now I have about 30% improvment.
However I want to know if you have also done w/r benchmark and what's
the result?
?? 2010-06-02 11:35 +0800??lwl??
> and, why did you set "JVM has 8G heap"?
> 8g, seems t
?? 2010-06-02 10:37 +0800??lwl??
> is all the 4 servers' MEM almost 100%?
Yes
> ?? 2010??6??2?? 10:12??Shuai Yuan ??
>
> Thanks lwl.
>
> Then is there anyway of tuning this, faster flush to disk or
> else?
>
> Cheers,
>
is all the 4 servers' MEM almost 100%?
在 2010年6月2日 上午10:12，Shuai Yuan 写道：
> Thanks lwl.
>
> Then is there anyway of tuning this, faster flush to disk or else?
>
> Cheers,
>
> Kevin
>
> 在 2010-06-02三的 09:57 +0800，lwl写道：
> > MEM: almost 100% (16GB)
> > -
> > maybe this is the bottl
Thanks lwl.
Then is there anyway of tuning this, faster flush to disk or else?
Cheers,
Kevin
?? 2010-06-02 09:57 +0800??lwl??
> MEM: almost 100% (16GB)
> -
> maybe this is the bottleneck.
> writing concerns Memtable and SSTable in memory.
>
> ?? 2010??6??2?? 9:48??S
MEM: almost 100% (16GB)
-
maybe this is the bottleneck.
writing concerns Memtable and SSTable in memory.
在 2010年6月2日 上午9:48，Shuai Yuan 写道：
> 在 2010-06-01二的 15:00 -0500，Jonathan Shook写道：
> > Also, what are you meaning specifically by 'slow'? Which measurements
> > are you looking a
?? 2010-06-01 15:00 -0500??Jonathan Shook??
> Also, what are you meaning specifically by 'slow'? Which measurements
> are you looking at. What are your baseline constraints for your test
> system?
>
Actually, the problem is the utilizaton of resources(for a single
machine):
CPU: 700% / 160
Also, what are you meaning specifically by 'slow'? Which measurements
are you looking at. What are your baseline constraints for your test
system?
2010/6/1 史英杰 :
> Hi, It would be better if we know which Consistency Level did you choose,
> and what is the schema of test data?
>
> 在 2010年6月1日 下午4:
Hi, It would be better if we know which Consistency Level did you choose,
and what is the schema of test data?
在 2010年6月1日 下午4:48，Shuai Yuan 写道：
> Hi all,
>
> I'm testing writing speed of cassandra with 4 servers. I'm confused by
> the behavior of cassandra.
>
> ---env---
> load-data app written
Hi all,
I'm testing writing speed of cassandra with 4 servers. I'm confused by
the behavior of cassandra.
---env---
load-data app written in c++, using libcassandra (w/ modified batch
insert)
20 writing threads in 2 processes running on 2 servers
---optimization---
1.turn log level to INFO
2.JVM
Hi all,
I'm testing writing speed of cassandra with 4 servers. I'm confused by
the behavior of cassandra.
---env---
load-data app written in c++, using libcassandra (w/ modified batch
insert)
20 writing threads in 2 processes running on 2 servers
---optimization---
1.turn log level to INFO
2.JVM
13 matches
Mail list logo
