NetLogger Example
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Description
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Graphs
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raw data and nlv_keys files
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Amber and Ganglia
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Data From Amber application (SC2003 demo). Includes CPU data.
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nlv results
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download
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Remote IO application (DPSS)
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This shows the results for a NetLogger Analysis of High Energy
Physics analysis application (STAF) doing a remote read of data on a
DPSS server. The blue, green, and brown lines are tracing a data read
request as it is send to the remote server. The lines fan out as a
single read request on the client get split into multiple disk reads
on the server. In this case data resided on 4 DPSS servers, hence the
4 colors of lines. The red lines show what is happening inside of the
STAF application. "PAM" is a CPU intensive operation, shown at the top
of the screen.
What we learn from this plot: This
application spends about twice as much time doing data
analysis as it spends doing remote IO. Overlapping I/O and
computation would result in a large increase in performance.
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nlv of STAF/DPSS
nlv of STAF/DPSS with analysis window
: This slows a zoomed in view of the above plot, along with the nlv analysis
window
nlv of DPSS client with many TCP streams
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download
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FTP application (Globus GridFTP)
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This is an example of using NetLogger to analyze
and debug the Globus GridFTP program. These results are client side only.
Note the large overhead (about 9 seconds) of the initial FTP handshaking.
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nlv of Globus IO
nlv of Globus
showing unbalanced streams bug
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download
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Visualization of Remote Data
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This is an example of how NetLogger was used
to tune a visualization application (Visapult) reading remote data from a
DPSS. Before adding NetLogger, the application sequentially did IO, followed
by computation. After seeing these results, it became clear that overlapping
IO with computation would help a lot.
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nlv of Visapult/DPSS; before tuning
: (sequential IO and computation)
nlv of Visapult/DPSS after tuning
: (overlapped IO and computation)
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Network Monitoring (NTAF)
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Example of using NetLogger to correlate
the results of several network tests
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nlv comparing iperf to pipechar results
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download
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web100 Monitoring (iperf)
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Example of how NetLogger can be used to analyze
the results of iperf running on a web100 Linux kernel
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iperf + web100
more iperf + web100
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download
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