Re: Asynchronous FTP Upload [message #172086 is a reply to message #172085] |
Sun, 30 January 2011 14:48 |
Luuk
Messages: 329 Registered: September 2010
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Senior Member |
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On 30-01-11 15:20, Jerry Stuckle wrote:
> On 1/30/2011 8:41 AM, Luuk wrote:
>> On 28-01-11 20:48, Jerry Stuckle wrote:
>>> On 1/28/2011 10:56 AM, duderion wrote:
>>>> On Jan 28, 4:29 pm, Jerry Stuckle<jstuck...@attglobal.net> wrote:
>>>> > On 1/28/2011 10:12 AM, duderion wrote:
>>>> >
>>>> >> hi guys,
>>>> >
>>>> >> could anyone tell me how i can handle an ftp upload to several
>>>> >> servers
>>>> >> at once?
>>>> >
>>>> >> I found fb_nb_put, but i dont know how to combine 5 connections with
>>>> >> this.
>>>> >
>>>> >> any help would be nice :)
>>>> >
>>>> >> dude
>>>> >
>>>> > You'll need to open 5 different streams and start each transfer. Keep
>>>> > track of the status of each transfer in an array and loop while any of
>>>> > them need to continue. In the loop, continue those which have not
>>>> > finished.
>>>> >
>>>> > Not sure what this is going to do though for you though, other than
>>>> > take
>>>> > a lot of unnecessary CPU because you're effectively polling
>>>> > constantly.
>>>> > Why don't you just upload each file individually?
>>>> >
>>>> Hi Jerry
>>>> thanks for the quick and nice reply,
>>>>
>>>> i need to do this, because i have to trasfer videos to around 500
>>>> hosts during one night. i have a 1gb upload line, and thats why i want
>>>> to run those uploads simultaniously....
>>>>
>>> <Top posting fixed>
>>>
>>> That doesn't mean you'll get anywhere near 1gb upload. Your limit in
>>> this case is likely going to be disk access speed (assuming the other
>>> hosts are replying in a timely manner, of course). And forcing the disk
>>> to jump around to fetch data from different areas of the disk is likely
>>> to be slower then accessing the data in a contiguous file.
>>>
>>> The point being - even if you open 5 parallel connections, you are not
>>> going to get 5x the speed; in fact, depending on what you're doing, you
>>> may actually slow down the processing. And error recovery becomes much
>>> harder.
>>
>> You might be true, but most of it depends on the download speed at the
>> receiving site. If its lower then 1/5 of your uploadspeed than you
>> should not worry ;)
>>
>
>
> Not really. You're not going to get 1gb/sec. or even 200mb/sec. from
> the disk drive, especially not continuously. So even if the download
> speed on the other end is 200mb/sec, that's still not going to be a
> limiting factor.
>
> And forcing the disk to pull data from several different files on the
> disk will slow disk overall disk access even more, especially if the
> files are contiguous.
But if the files are send to 500 hosts, the file might be in cache, if
enough memory is available, which should speed up disk-access again.. ;)
>
>>>
>>> You need to test and find out. The "sweet spot" may be anywhere from 1
>>> to 500 parallel connections (although I highly doubt the latter :) ).
>>> And it may vary depending on exactly which hosts you're currently
>>> accessing and how quickly they respond.
>>>
>>> P.S. Please don't top post. Thanks.
>>>
>>
>>
--
Luuk
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