perfsonar-user - Re: [perfsonar-user] Different results from iperf3 vs. bwctl -T iperf3
Subject: perfSONAR User Q&A and Other Discussion
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- From: Brian Candler <>
- To: Aaron Brown <>
- Cc: "" <>
- Subject: Re: [perfsonar-user] Different results from iperf3 vs. bwctl -T iperf3
- Date: Thu, 11 Dec 2014 00:04:28 +0000
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I made little headway in narrowing this down.
I added some debugging in bwctl.c wait_for_results. When the total test times were ~45 seconds, I was able to see that the difference between the req_time and the current time was 35 seconds (but duration=10, omit=0, fuzz=just over 1 second). So it's something to do with calculating the future request time.
I have also seen cases of wait_for_results saying times of over 80 seconds.
I then added further debugging, but by the time I did this, it was back to "working" again - 15 seconds per test :-(
At bwctl client side:
bwctl: BWLGetTimeStamp: errest=2100000
bwctl: BWLSetTimeStampError: val=9019431321
bwctl: BWLSetTimeStampError: scale=26, multiplier=135
bwctl: BWLGetTimeStamp: errest=2100000
bwctl: BWLSetTimeStampError: val=9019431321
bwctl: BWLSetTimeStampError: scale=26, multiplier=135
That's fine: 0.1 is the default skew estimate, and I put -a 2 on the command line.
On bwctld:
bwctld[16642]: FILE=time.c, LINE=395, BWLGetTimeStamp: errest=100000
bwctld[16642]: FILE=time.c, LINE=718, BWLSetTimeStampError: val=429496729
bwctld[16642]: FILE=time.c, LINE=736, BWLSetTimeStampError: scale=21, multiplier=205
bwctld[16642]: FILE=time.c, LINE=395, BWLGetTimeStamp: errest=100000
bwctld[16642]: FILE=time.c, LINE=718, BWLSetTimeStampError: val=429496729
bwctld[16642]: FILE=time.c, LINE=736, BWLSetTimeStampError: scale=21, multiplier=205
This is all fine. 429496729.0/(1<<32) ~= 0.1 seconds.
I can only guess that in some circumstances large fuzz or offset values are being used, but fiddling with BWCTL_DEBUG_TIMEOFFSET I am not able to recreate the problem.
Unfortunately I'm running out of time now as (a) it's late, and (b) tomorrow these boxes get shipped out :-(
Regards,
Brian.
- Re: [perfsonar-user] Different results from iperf3 vs. bwctl -T iperf3, (continued)
- Re: [perfsonar-user] Different results from iperf3 vs. bwctl -T iperf3, Brian Candler, 12/05/2014
- Re: [perfsonar-user] Different results from iperf3 vs. bwctl -T iperf3, Brian Candler, 12/06/2014
- RE: [perfsonar-user] Different results from iperf3 vs. bwctl -T iperf3, Tim Rayner, 12/06/2014
- Re: [perfsonar-user] Different results from iperf3 vs. bwctl -T iperf3, Brian Candler, 12/07/2014
- Re: [perfsonar-user] Different results from iperf3 vs. bwctl -T iperf3, Brian Candler, 12/07/2014
- Re: [perfsonar-user] Different results from iperf3 vs. bwctl -T iperf3, Aaron Brown, 12/09/2014
- Re: [perfsonar-user] Different results from iperf3 vs. bwctl -T iperf3, Brian Candler, 12/09/2014
- Re: [perfsonar-user] Different results from iperf3 vs. bwctl -T iperf3, Brian Candler, 12/09/2014
- Re: [perfsonar-user] Different results from iperf3 vs. bwctl -T iperf3, Aaron Brown, 12/10/2014
- Re: [perfsonar-user] Different results from iperf3 vs. bwctl -T iperf3, Brian Candler, 12/10/2014
- Re: [perfsonar-user] Different results from iperf3 vs. bwctl -T iperf3, Brian Candler, 12/11/2014
- Re: [perfsonar-user] Different results from iperf3 vs. bwctl -T iperf3, Aaron Brown, 12/11/2014
- Re: [perfsonar-user] Different results from iperf3 vs. bwctl -T iperf3, Brian Candler, 12/11/2014
- Re: [perfsonar-user] Different results from iperf3 vs. bwctl -T iperf3, Brian Candler, 12/07/2014
- Re: [perfsonar-user] Different results from iperf3 vs. bwctl -T iperf3, Brian Candler, 12/07/2014
- RE: [perfsonar-user] Different results from iperf3 vs. bwctl -T iperf3, Tim Rayner, 12/06/2014
- Re: [perfsonar-user] Different results from iperf3 vs. bwctl -T iperf3, Brian Candler, 12/10/2014
- Re: [perfsonar-user] Different results from iperf3 vs. bwctl -T iperf3, Brian Candler, 12/11/2014
- Re: [perfsonar-user] Different results from iperf3 vs. bwctl -T iperf3, Brian Candler, 12/06/2014
- Re: [perfsonar-user] Different results from iperf3 vs. bwctl -T iperf3, Brian Candler, 12/05/2014
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