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Demonstrations of ustat.
ustat is a "top"-like tool for monitoring events in high-level languages. It
prints statistics about garbage collections, method calls, object allocations,
and various other events for every process that it recognizes with a Java,
Python, Ruby, Node, or PHP runtime.
For example:
# ./ustat.py
Tracing... Output every 10 secs. Hit Ctrl-C to end
12:17:17 loadavg: 0.33 0.08 0.02 5/211 26284
PID CMDLINE METHOD/s GC/s OBJNEW/s CLOAD/s EXC/s THR/s
3018 node/node 0 3 0 0 0 0
^C
Detaching...
If desired, you can instruct ustat to print a certain number of entries and
exit, which can be useful to get a quick picture on what's happening on the
system over a short time interval. Here, we ask ustat to print 5-second
summaries 12 times (for a total time of 1 minute):
# ./ustat.py -C 5 12
Tracing... Output every 5 secs. Hit Ctrl-C to end
12:18:26 loadavg: 0.27 0.11 0.04 2/336 26455
PID CMDLINE METHOD/s GC/s OBJNEW/s CLOAD/s EXC/s THR/s
3018 node/node 0 1 0 0 0 0
12:18:31 loadavg: 0.33 0.12 0.04 2/336 26456
PID CMDLINE METHOD/s GC/s OBJNEW/s CLOAD/s EXC/s THR/s
3018 node/node 0 0 0 0 0 0
26439 java -XX:+ExtendedDT 2776045 0 0 0 0 0
12:18:37 loadavg: 0.38 0.14 0.05 2/336 26457
PID CMDLINE METHOD/s GC/s OBJNEW/s CLOAD/s EXC/s THR/s
3018 node/node 0 0 0 0 0 0
26439 java -XX:+ExtendedDT 2804378 0 0 0 0 0
(...more output omitted for brevity)
USAGE message:
# ./ustat.py -h
usage: ustat.py [-h] [-l {java,python,ruby,node,php}] [-C]
[-S {cload,excp,gc,method,objnew,thread}] [-r MAXROWS] [-d]
[interval] [count]
Activity stats from high-level languages.
positional arguments:
interval output interval, in seconds
count number of outputs
optional arguments:
-h, --help show this help message and exit
-l {java,python,ruby,node,php}, --language {java,python,ruby,node,php}
language to trace (default: all languages)
-C, --noclear don't clear the screen
-S {cload,excp,gc,method,objnew,thread}, --sort {cload,excp,gc,method,objnew,thread}
sort by this field (descending order)
-r MAXROWS, --maxrows MAXROWS
maximum rows to print, default 20
-d, --debug Print the resulting BPF program (for debugging
purposes)
examples:
./ustat # stats for all languages, 1 second refresh
./ustat -C # don't clear the screen
./ustat -l java # Java processes only
./ustat 5 # 5 second summaries
./ustat 5 10 # 5 second summaries, 10 times only