Hi,
Since you're iterating the whole set with several records a time, your
code should know when it's first time.
Why just simply
if(!_first_time){
_iter++; //to ignore the first record?
}else{
_first_time=false;
}
Kevin Yuan,
Supertool Corp.
www.yuan-shuai.info
On 2010?06?10? 22:0
Would you please tell the performance you measured? Although I don't
have any experience relating to flash-drive, I'm very interested in
switching to SSD.
So far from my benchmark, the bottleneck of cassandra just doesn't seem
to be disk_io, but memory.
Kevin Yuan,
Supertool Corp.
www.yuan-s
Ellis
??: user@cassandra.apache.org
: [***SPAM*** ] Re: problem when trying to get_range_slice()
: Thu, 3 Jun 2010 19:07:28 -0700
use smaller slices and page through the data
2010/6/3 Shuai Yuan :
> Hi all,
>
> my env
>
> 6 servers with about 200GB data.
>
> data s
e.setReversed(true);
> range.setCount(20);
>
> SlicePredicate sp = new SlicePredicate();
> sp.setSlice_range(range);
>
> client.get_slice(KEYSPACE, KEY, ColumnParent, sp, ConsistencyLevel.ONE);
> 2010/6/1 Shuai Yuan
> Hi all,
>
> I don't quite understand the usage of 'c
more info:
CL = ONE,
replica = 2,
and when I tried to monitor the disk_io with iostat I get almost 0MB/s
read & 0% CPU on the machine the scan-data app started on.
Thanks!
??: Shuai Yuan
??: user@cassandra.apache.org
: [***SPAM*** ] problem when tr
Hi all,
my env
6 servers with about 200GB data.
data structure,
64B rowkey + (5B column)*20,
rowkey and column.value are all random bytes from a-z,A-Z,0-9
problem
when I tried iterate over the data in the storage, I always get
org::apache::cassandra::TimedOutException
(RpcTim
Thanks Peter!
In my test application, for each record,
rowkey -> rand() * 4, about 64B
column * 20 -> rand() * 20, about 320B
I use batch_insert(rowkey, col*20) in thrift.
Kevin Yuan
??: Peter Sch??ller
??: user@cassandra.apache.org
: [***SPAM*** ] Re:
+0800??lwl??
> No.
> But I did some capacity tests about another distributed system.
> Your former test cost too much MEM, it was the bottleneck.
> caches and JVM cost MEM, so I suggested to decrease them.
>
>
> What is the bottleneck of your current test now?
>
>
maybe you can try to decrease the size of caches.
>
> ?? 2010??6??2?? 11:14??Shuai Yuan
> ??
>
>
> ?? 2010-06-02 10:37 +0800??lwl??
> > is all the 4 servers&#x
?? 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?
&
0??6??2?? ????9:48??Shuai Yuan ??
>
> ?? 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 const
#x27;s neither a promising result.
Thanks!
Kevin
>
> 2010/6/1 ?? :
> > Hi, It would be better if we know which Consistency Level did you choose,
> > and what is the schema of test data?
> >
> > ?? 2010??6??1?? 4:48??Shuai Yuan ??
> >>
> >>
Hi all,
I don't quite understand the usage of 'class SlicePredicate' when trying
to retrieve a ranged slice.
How should it be initialized?
Thanks!
--
Kevin Yuan
www.yuan-shuai.info
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
?? 2010-06-01 15:00 +0800??huajun qi??
> If you have a multinode cluster, which node you should connect to
> fetch data?
any one.
>
> Is there a master node in a cluster which accepts data request and
> dispatch it? Or every node in the cluster is completely same?
no master. all the same.
-opinion---
So, have you checked the writing speed of cassandra? I feel it's quite
slow currently.
Could anyone confirm this is the normal writing speed of cassandra, or
please provide someway of improving it?
--
Shuai Yuan
Supertool Corp. ??
13810436859
yuan-sh...@yuan-shuai.info
16 matches
Mail list logo
