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