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From Patrick Hunt <ph...@apache.org>
Subject Re: ZK on EC2
Date Tue, 10 Nov 2009 05:47:15 GMT
Interesting, so comparing a large (4cores and "high" i/o performance) 
ec2 instance (the first number on each line below) vs the host I used in 
the latency test (the second number on each line):

ebs cache        817 vs 11532 ~  7% (ec2 7% as performant)
ebs bufread       53 vs    88 ~ 60%
native cache     829 vs 11532 ~  7%
native bufread    80 vs    88 ~ 90%

dd 512m 106s vs 74s ~ 43% longer for ec2 large

md5sum 512m 2.13s vs 1.5 ~ 42% longer

Good thing we don't rely on disk cache. ;-) Raw processing power looks 
about half. Could you test networking - scping data between hosts? (I 
was seeing 64.1MB/s for a 512mb file - the one created by dd, random data)

Small anyone?

Patrick

Ted Dunning wrote:
> /dev/sdp is an EBS volume.  /dev/sdb is a native volume.
> 
> This is a large instance.
> 
> root@domU-<mumble>#:~# hdparm -tT /dev/sdp
> 
> /dev/sdp:
>  Timing cached reads:   1634 MB in  2.00 seconds = 817.30 MB/sec
>  Timing buffered disk reads:  160 MB in  3.00 seconds =  53.27 MB/sec
> root@domU-<mumble>:~# hdparm -tT /dev/sdb
> 
> /dev/sdb:
>  Timing cached reads:   1658 MB in  2.00 seconds = 829.44 MB/sec
>  Timing buffered disk reads:  242 MB in  3.00 seconds =  80.56 MB/sec
> root@domU-<mumble>:~# time dd if=/dev/urandom bs=512000 of=/tmp/memtest
> count=1050
> 1050+0 records in
> 1050+0 records out
> 537600000 bytes (538 MB) copied, 106.525 s, 5.0 MB/s
> 
> real    1m46.517s
> user    0m0.000s
> sys    1m46.127s
> root@domU-<mumble>:~# time md5sum /tmp/memtest; time md5sum /tmp/memtest;
> time md5sum /tmp/memtest
> f79304f68ce04011ca0aebfbd548134a  /tmp/memtest
> 
> real    0m2.234s
> user    0m1.613s
> sys    0m0.590s
> f79304f68ce04011ca0aebfbd548134a  /tmp/memtest
> 
> real    0m2.136s
> user    0m1.560s
> sys    0m0.584s
> f79304f68ce04011ca0aebfbd548134a  /tmp/memtest
> 
> real    0m2.123s
> user    0m1.640s
> sys    0m0.481s
> root@domU-<mumble>:~#
> 
> 
> On Mon, Nov 9, 2009 at 4:54 PM, Patrick Hunt <phunt@apache.org> wrote:
> 
>> I'm really interested to know how ec2 compares wrt disk and network
>> performance to what I've documented here under the "hardware" section:
>> http://wiki.apache.org/hadoop/ZooKeeper/ServiceLatencyOverview#Hardware
>>
>> Is it possible for someone to compare the network and disk performance
>> (scp, dd, md5sum, etc...) that I document in the wiki page on say, EC2
>> small/large nodes? I'd do it myself but I've not used ec2. If anyone could
>> try these and report I'd appreciate it.
>>
>> Patrick
>>
>>
>> Ted Dunning wrote:
>>
>>> Worked pretty well for me.  We did extend all of our timeouts.  The
>>> biggest
>>> worry for us was timeouts on the client side.  The ZK server side was no
>>> problem in that respect.
>>>
>>> On Mon, Nov 9, 2009 at 4:20 PM, Jun Rao <junrao@almaden.ibm.com> wrote:
>>>
>>>  Has anyone deployed ZK on EC2? What's the experience there? Are there
>>>> more
>>>> timeouts, lead re-election, etc? Thanks,
>>>>
>>>> Jun
>>>> IBM Almaden Research Center
>>>> K55/B1, 650 Harry Road, San Jose, CA  95120-6099
>>>>
>>>> junrao@almaden.ibm.com
>>>>
>>>
>>>
>>>
>>>
> 
> 

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