Transcript 3d_network_diagnostic_tools__BNL

BNL’s Network diagnostic tool
IPERF was used and combined with different strategies to analyze network bandwidth performance such
as:
-Test with iperf server inside firewall (where oracle cluster resides)
-Test with iperf server outside firewall.
-Test with client at CERN to host inside/outside BNL firewall
-Test with client inside BNL’s firewall host inside firewall
-Test with client at BNL’s bounder firewall host inside firewall.
These tests can be deployed for different well known parameters IPERF tool has such:
-w, TCP window size (64KB- 8MB)
- t, time to transmit (default 10 seconds)
-P, number of parallel clients threats.
BNL’s simple test to show firewall impact on bandwidth using IPERF
Test IPERFSingle Stream
Client host
CERN 137.138.76.18
iperf -c oraclus02.usatlas.bnl.gov
-w 2MB -t 40 -i 5 -p 3938
iperf -c dcdoor02.usatlas.bnl.gov w 2MB -t 40 -i 5 -p 22000
Host/Location
Bandwidth
Oraclus02 Inside firewall
130.199.185.13
40.0Mbits/sec
Door Outside firewall
192.12.15.3
77.5 Mbits/sec
BNL’s elaborated test using IPERF to study firewall’s impact on bandwidth
Firewall effect, campus net
1000
900
800
Host/Location
700
Mbps (rx)
netqos01-dcdoor03
600
netqos02-dcdoor03
netqos01-gridgk01
500
netqos02-gridgk01
netqos01-gridgk02
400
netqos02-gridgk02
300
200
100
0
0
200
400
600
800
1000
1200
Mbps (tx)
Fig 1. By Dimitrios Katramatos
-Single iperf stream with bandwidth throttled at the router.
-Test performed the same day same network traffic.
-Results showed how the bandwidth is constrained by the firewall.
Inside firewall
gridgk01
gridgk02
Outside firewall
dcdoor03
netgos02
netogos01
Web100 based Network Diagnostic Tool (NDT)
-Performs 2 TCP throughput tests between the host originator and the NDT server
-Data is streamed for 10 seconds from host originator, then a second 10 second test
is performed in opposite direction.
-A web100 modified Linux kernel captures statistics on TCP data flows.
-The Web100 software implements instruments in the Linux TCP/IP stack.
-Deals with the problem of host systems that is optimized for low bandwidth environments,
and the lack of effective instrumentation and tools to diagnose performance issues.
-The NDT tool can diagnose excessive packet loss due to faulty cable.
-If the buffer size from the host originator is low the tool reports to increase it.
In order to access this tool a web browser and java needs to be installed on the host originator
Other publicly accessible NDT servers:
* Argonne National Laboratory - IL (USA)
* Swiss Education and Research Network (Switzerland)
* Rochester Institute of Technology - Rochester NY (USA)
* University of Michigan - Flint MI (USA)
* University of California - Santa Cruz CA (USA)
BNL’s NDT test
Test NDT
Originator Host
NDT SERVER
http://newmon.bnl.gov:7123/ 130.199.3.7
Inside BNL Firewall
gridgk01.usatlas.bnl.gov
130.199.185.6
CP/Web100 Network Diagnostic Tool v5.3.3e
click START to begin
Checking for Middleboxes . . . . . . . . . . . . . . . . . . Done
running 10s outbound test (client to server) . . . . . 496.99Mb/s
running 10s inbound test (server to client) . . . . . . 604.12Mb/s
Outside BNL Firewall
dct00.usatlas.bnl.gov
192.12.15.8
CP/Web100 Network Diagnostic Tool v5.3.3e
click START to begin
Checking for Middleboxes . . . . . . . . . . . . . . . . . . Done
running 10s outbound test (client to server) . . . . . 943.87Mb/s
running 10s inbound test (server to client) . . . . . . 846.62Mb/s