NjmonLinuxManualPage

njmon(1) General Commands Manual njmon(1)

NAME

       njmon - capture Linux Performance stats in JSON format - default is stdout

SYNOPSIS

       Output njmon version and stop:

       njmon -@

       Output this help information and stop:

       njmon -h or -?

       The command line options are in the file:

       njmon -a file

       Collect performance statistics to a file:

       njmon -s seconds -c count -m dir -f [-k | -K pidfile] -n -P -t percent -e -b -d -R -F

       Collect performance statistics for a central njmon.py service:

       njmon -s seconds -c count -m dir [-k | -K pidfile] -n -P -t percent -e -b -d -r -R -F -i hostname -p port
       -X secret

       Collect performance statistics for a central njmon.py service using a shell variable:

       export NMON_SECRET=secret

       njmon -s seconds -c count -m dir -k -n -P -t percent -e -b -d -r -R -F -i hostname -p port

OPTIONS

-a file
Command line arguments are in the file (hides passwords) Use the same arguments, all on the first
line, space separated Only have the -a option on the actual command line

-s seconds
seconds between snapshots of data (default 60 seconds)

-c count
number of snapshots (default forever)

-m directory
The program will change to the directory before output or creating a file

-f Output the statistics to following files (instead of stdout), "lp" for line protocal:
Data: hostname_<year><month><day>_<hour><minutes>.json
Error: hostname_<year><month><day>_<hour><minutes>.err
Note: problems can occur if using this option and the -i option as the data can't go both to a
file and to a socket.

-k If the file /tmp/nimon.pid is not found this nimon continues running. If the file is found, the
process PID is read from it & if it is found that the process is running then this nimon exits.
If no process is found running then this nimon continues running. This allows you to try starting
nimon say once an hour from crontab. This will restart the nimon only if the previous one
stopped. nimon will remove the nimon.pid, file when it stops normally.
If the /tmp/njmon.pid is found but can't be accessed, nimon will print a warning and stop. The
file could be owned by a different user or no read permission.

-K pidfile
This is same as the -k option but the user decides the directory and filename for the file con\u2010
taining the Process ID(PID_. Plus you can run multiple nimon processes, using different PID
files. Some users prefer to use a file in, for example, /var/logs but that requires root access.
Others prefer to avoid /tmp.
Alternative, if you need to use a different filename then set the shell environemnt NJI\u2010
MON_PID_FILE, before starting njmon.
If the .pid file is found but can't be accessed, nimon will print a warning and stop. The file
could be owned by a different user or no read permission.

-P Add individual process stats. If the systems has hudored or more processes this option cat drasti\u2010
cally increase njmon CPU time and drastically increase the number of stats. This has implications
on database sizes.

-t percent
Set ignore process CPU use percent threshold (default 0.01%)

-e Switch on "elastic" (also called ElasticSearch) sub-sections are arrays rather than JSON struc\u2010
tures for example: disks, networks & filesystems

-b Switch off adding pid to the process names: "ksh_76927" -> "ksh"

-d Switch on debug tracing (output may no longer be JSON or InfluxDB Line Protocol format). This is
only useful for debugging the njmon code where the output has a problem.
Used this with the -f option to save the debug output to the .err file. This can be useful to
determine why some features are getting turned off like GPFS or socket issues.

-W Switch off warning messages in error output stream. Use this once you are confident that the warn\u2010
ings are ignorable. This includes badly behaved file systems like mounted but without root access.

-n No PID printed out at start up.

-r Random start pause. Stops cron making every program send data in sync.

-R Reduced stats - skip logical CPU stats for SMT threads.

-F Switch off filesystem stats (autofs and tmpfs can cause issues)

-i IP address or hostname
IP address or Hostname of the njmon central njmond.py daemon

-p port
port number of the central njmond.py host

-X secret
Depreciated: Set the remote collector secret or use shell NJMON_SECRET. This only is accepted but
ignored.

Notes on Spectrum Scale (GPFS)
njmon automatically collects GPFS if /usr/lpp/mmfs/bin/mmksh and /usr/lpp/mmfs/bin/mmpmon are
found on you systems. However, if GPFS is present but off it can get confused. Use: export
NOGPFS=1 to set a shell variable before running njmon will disable GPFS stats. You can also com\u2010
pile out GPFS support with -D NOGPFS

EXAMPLES

       Assuming njmon is found at /usr/local/bin and in our $PATH

       1      Collect stats every 5 mins for 24 hours and save the file in /home/perf

              njmon -s 300 -c 288 -f -m /home/perf

       2      Piping the stats to data handler program (perhaps in Python) all day at 30 second intervals

              njmon -s 30 -c 1440 | myprog

       3      Use the defaults (-s 60 -c forever) and save to a file. Assumes njmon is in your $PATH.

              njmon > my_server_today.json

       4      Send data to the central njmond.py daemon with no password

              njmon -s 30 -c 2880 -i admin.acme.com -p 8181

       5      Send data to the central njmond.py daemon with process stats and with password

              njmon -s 60 -c 1440 -P -i admin.acme.com -p 8181 -X password

       6      Crontab entry to only save to a file (2 minutes past midnight) in the /home/perf directory

              2 0 * * * /usr/local/bin/njmon -s 60 -c 1440 -f -m /home/perf >/dev/null

       7      Crontab entry to start daily at midnight and sending data to central server

              0 0 * * * /usr/local/bin/njmon -s 30 -c 2880 -i admin.acme.com -p 8181 >/dev/null

       8      Crontab entry to send data to central server, every hour of the day (if njmon is found to be  run\u2010
              ning already this invokation stops quitely)


              0 * * * * /usr/local/bin/njmon -k -s 30 -i admin.acme.com -p 8181 >/dev/null

       9      Crontab use ssh to start njmon, send data back via socket to a local InfluxDB "injector" program

              0 0 * * * ssh root@endpoint /usr/local/bin/njmon -s 30 -c 2880 -i admin.acme.com -p 8181 >/dev/null

VERSIONS

       Version 70 - New support for Mainframe / IBM Z platform.
              Include -D MAINFRAME in the compile line of the Makfile.
              Tested only of RHEL, so far.

AUTHOR

       Developer Nigel Griffiths (nigelargriffiths@hotmail.com)

       License GPLv3+: GNU GPL version 3