On 8/20/09 9:48 AM, "Ananth T. Sarathy" <[email protected]> wrote:

> ok.. i seems that's the case.  that seems kind of  selfdefeating though.
> 
> Ananth T Sarathy

Then something is wrong with S3.  It may be misconfigured, or just poor
performance.  I have no experience with S3 but 20 seconds to connect
(authenticate?) and open a file seems very slow for any file system.

> 
> 
> On Thu, Aug 20, 2009 at 12:31 PM, Scott Carey <[email protected]>wrote:
> 
>> If it always takes a very long time to start transferring data, get a few
>> stack dumps (jstack or kill -e) during this period to see what it is doing
>> during this time.
>> 
>> Most likely, the client is doing nothing but waiting on the remote side.
>> 
>> 
>> On 8/20/09 8:02 AM, "Ananth T. Sarathy" <[email protected]>
>> wrote:
>> 
>>> it's not really 1 mbps so much it takes 2 minutes to start doing the
>>> reads.....
>>> 
>>> Ananth T Sarathy
>>> 
>>> 
>>> On Wed, Aug 19, 2009 at 4:30 PM, Scott Carey <[email protected]
>>> wrote:
>>> 
>>>> 
>>>> On 8/19/09 10:58 AM, "Raghu Angadi" <[email protected]> wrote:
>>>> 
>>>>> Edward Capriolo wrote:
>>>>>>> On Wed, Aug 19, 2009 at 11:11 AM, Edward Capriolo
>>>>>>> <[email protected]>wrote:
>>>>>>> 
>>>>>>>>>> It would be as fast as underlying filesystem goes.
>>>>>>>> I would not agree with that statement. There is overhead.
>>>>> 
>>>>> You might be misinterpreting my comment. There is of course some over
>>>>> head (at the least the procedure calls).. depending on you underlying
>>>>> filesystem, there could be extra buffer copies and CRC overhead. But
>>>>> none of that explains transfer as slow as 1 MBps (if my interpretation
>>>>> of of results is correct).
>>>>> 
>>>>> Raghu.
>>>> 
>>>> 
>>>> Yes, there is nothing about distributing work for parallel execution
>> that
>>>> is
>>>> going to make a single 20MB file transfer faster.   That is very slow,
>> and
>>>> should be on the order of a second or so, not multiple minutes.
>>>>  Something else is wrong.
>>>> 
>>>> 
>>>> 
>>> 
>> 
>> 
> 

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