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computezrmle
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Message 30210 - Posted: 4 May 2017, 14:29:11 UTC

The following information may be of interest to users with a slow internet connection.

At the end of each calculation cycle an LHCb job uploads it's result file to a CERN system through port 9148.
Those result files differ in size.
I measured 54 - 123 MB on my hosts today.

While the upload is in progress the CPU used by the VM is nearly idle.
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Pavel Hanak

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Message 30624 - Posted: 4 Jun 2017, 11:04:39 UTC - in response to Message 30210.  
Last modified: 4 Jun 2017, 11:07:40 UTC

Yeah, this is what irks me about LHCb, because I have slow upload speed (50 KB/s) on one of my machines. In essence, LHCb wastes CPU time this way. In my case, it would have been much more efficient if LHCb downloaded data for the next cycle and continued computation while the upload is taking place.

I hope the scientists will add this feature later...
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Erich56

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Message 30627 - Posted: 4 Jun 2017, 14:24:46 UTC - in response to Message 30210.  

...While the upload is in progress the CPU used by the VM is nearly idle.

Just FYI: same is true for CMS.
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computezrmle
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Message 30629 - Posted: 4 Jun 2017, 16:01:17 UTC - in response to Message 30627.  

...While the upload is in progress the CPU used by the VM is nearly idle.

Just FYI: same is true for CMS.

Right.

Although CMS uses an HTTP port for uploads and is therefore easy to monitor and it can be redirected through a standard proxy.
LHCb uploads via a very unusual port (TCP 9148).
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