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38 lines
1.3 KiB
38 lines
1.3 KiB
Demonstrations of gethostlatency, the Linux eBPF/bcc version.
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This traces host name lookup calls (getaddrinfo(), gethostbyname(), and
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gethostbyname2()), and shows the PID and command performing the lookup, the
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latency (duration) of the call in milliseconds, and the host string:
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# ./gethostlatency
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TIME PID COMM LATms HOST
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06:10:24 28011 wget 90.00 www.iovisor.org
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06:10:28 28127 wget 0.00 www.iovisor.org
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06:10:41 28404 wget 9.00 www.netflix.com
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06:10:48 28544 curl 35.00 www.netflix.com.au
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06:11:10 29054 curl 31.00 www.plumgrid.com
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06:11:16 29195 curl 3.00 www.facebook.com
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06:11:25 29404 curl 72.00 foo
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06:11:28 29475 curl 1.00 foo
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In this example, the first call to lookup "www.iovisor.org" took 90 ms, and
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the second took 0 ms (cached). The slowest call in this example was to "foo",
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which was an unsuccessful lookup.
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USAGE message:
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# ./gethostlatency -h
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usage: gethostlatency [-h] [-p PID]
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Show latency for getaddrinfo/gethostbyname[2] calls
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optional arguments:
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-h, --help show this help message and exit
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-p PID, --pid PID trace this PID only
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examples:
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./gethostlatency # trace all TCP accept()s
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./gethostlatency -p 181 # only trace PID 181
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