Collectl
	Latest Version: 4.3.1 Oct 31, 2018

To use it download the tarball, unpack it and run ./INSTALL
Collectl now supports OpenStack Clouds
Colmux now part of collectl package
Looking for colplot? It's now here!

Remember, to get lustre support contact Peter Piela to get his custom plugin.

There are a number of times in which you find yourself needing performance data. These can include benchmarking, monitoring a system's general heath or trying to determine what your system was doing at some time in the past. Sometimes you just want to know what the system is doing right now. Depending on what you're doing, you often end up using different tools, each designed to for that specific situation.

Unlike most monitoring tools that either focus on a small set of statistics, format their output in only one way, run either interatively or as a daemon but not both, collectl tries to do it all. You can choose to monitor any of a broad set of subsystems which currently include buddyinfo, cpu, disk, inodes, infiniband, lustre, memory, network, nfs, processes, quadrics, slabs, sockets and tcp.

The following is an example taken while writing a large file and running the collectl command with no arguments. By default it shows cpu, network and disk stats in brief format. The key point of this format is all output appears on a single line making it much easier to spot spikes or other anomalies in the output:

collectl

#<--------CPU--------><-----------Disks-----------><-----------Network---------->
#cpu sys inter  ctxsw KBRead  Reads  KBWrit Writes netKBi pkt-in  netKBo pkt-out
  37  37   382    188      0      0   27144    254     45     68       3      21
  25  25   366    180     20      4   31280    296      0      1       0       0
  25  25   368    183      0      0   31720    275      2     20       0       1

collectl -sjmf -oT

#         <-------Int--------><-----------Memory-----------><------NFS Totals------>
#Time     Cpu0 Cpu1 Cpu2 Cpu3 Free Buff Cach Inac Slab  Map  Reads Writes Meta Comm
08:36:52  1001   66    0    0   2G 201M 609M 363M 219M 106M      0      0    5    0
08:36:53   999 1657    0    0   2G 201M   1G 918M 252M 106M      0  12622    0    2
08:36:54  1001 7488    0    0   1G 201M   1G   1G 286M 106M      0  20147    0    2

collectl -sn --verbose -oT

# NETWORK SUMMARY (/sec)
#          KBIn  PktIn SizeIn  MultI   CmpI  ErrIn  KBOut PktOut  SizeO   CmpO ErrOut
08:46:35   3255  41000     81      0      0      0 112015  78837   1454      0      0
08:46:36      0      9     70      0      0      0     29     25   1174      0      0
08:46:37      0      2     70      0      0      0      0      2    134      0      0

collectl -sJ -oTm

#              Int    Cpu0   Cpu1   Cpu2   Cpu3   Type            Device(s)
08:52:32.002   225       0      4      0      0   IO-APIC-level   ioc0
08:52:32.002   000    1000      0      0      0   IO-APIC-edge    timer
08:52:32.002   014       0      0     18      0   IO-APIC-edge    ide0
08:52:32.002   090       0      0      0  15461   IO-APIC-level   eth1

Are you a big user of the top command? Have you ever wanted to look across a cluster to see what the top processes are? Better yet, how about using iostat across a cluster? Or maybe vmstat or even looking at top network interfaces across a cluster? Look no more because if collectl reports it for one node, colmux can do it across a cluster AND you can sort by any column of your choice by simply using the right/left arrow keys.

Collectl and Colmux run on all linux distros and are available in redhat and debian respositories and so getting it may be as simple as running yum or apt-get. Note that since colmux has just been merged into the collectl V4.0.0 package it may not yet be available in the repository of your choice and you should install collectl-utils V4.8.2 or earlier to get it for the time being.

Collectl requires perl which is usually installed by default on all major Linux distros and optionally uses Time::Hires which is also usually installed and allows collectl to use fractional intervals and display timestamps in msec. The Compress::Zlib module is usually installed as well and if present the recorded data will be compressed and therefore use on average 90% less storage when recording to a file.

If you're still not sure if collectl is right for you, take a couple of minutes to look at the Collectl Tutorial to get a better feel for what collectl can do. Also be sure to check back and see what's new on the website, sign up for a Mailing List or watch the Forums.