Wrapped CBench (WCBench)

CBench, wrapped in stuff that makes it useful.

• Wrapped CBench (WCBench)
  • Overview
  • Usage
    • Usage Overview
    • Usage Details: wcbench.sh
    • Usage Details: loop_wcbench.sh
    • Usage Details: stats.py
  • WCBench Results
  • Detailed Walkthrough: Vagrant
  • Detailed Walkthrough: Manual
  • Contributing
  • Contact

Overview

CBench is a somewhat classic SDN controller benchmark tool. It blasts a controller with OpenFlow packet-in messages and counts the rate of flow mod messages returned. WCBench consumes CBench as a library, then builds a robust test automation, stats collection and stats analysis/graphing system around it.

WCBench currently only supports the Helium release of the OpenDaylight SDN controller, but it would be fairly easy to add support for other controllers. Community contributions are encouraged!

Usage

Usage Overview

The help outputs produced by ./wcbench.sh -h, ./loop_wcbench.sh -h and stats.py -h are quite useful:

Usage ./wcbench.sh [options]

Setup and/or run CBench and/or OpenDaylight.

OPTIONS:
    -h Show this message
    -v Output verbose debug info
    -c Install CBench
    -t <time> Run CBench for given number of minutes
    -r Run CBench against OpenDaylight
    -i Install OpenDaylight Helium 0.2.3
    -p <processors> Pin ODL to given number of processors
    -o Start and configure OpenDaylight Helium 0.2.3
    -k Kill OpenDaylight
    -d Delete local ODL and CBench code

Usage ./loop_wcbench.sh [options]

Run WCBench against OpenDaylight in a loop.

OPTIONS:
    -h Show this help message
    -v Output verbose debug info
    -l <num_runs> Loop WCBench given number of times without restarting ODL
    -r <num_runs> Loop WCBench given number of times, restart ODL between runs
    -t <time> Run WCBench for a given number of minutes
    -p <processors> Pin ODL to given number of processors

usage: stats.py [-h] [-S]
                [-s {five_load,ram,steal_time,one_load,iowait,fifteen_load,runtime,flows} [{five_load,ram,steal_time,one_load,iowait,fifteen_load,runtime,flows} ...]]
                [-G]
                [-g {five_load,ram,steal_time,one_load,iowait,fifteen_load,runtime,flows} [{five_load,ram,steal_time,one_load,iowait,fifteen_load,runtime,flows} ...]]

Compute stats about CBench data

optional arguments:
  -h, --help            show this help message and exit
  -S, --all-stats       compute all stats
  -s {five_load,ram,steal_time,one_load,iowait,fifteen_load,runtime,flows} [{five_load,ram,steal_time,one_load,iowait,fifteen_load,runtime,flows} ...], --stats {five_load,ram,steal_time,one_load,iowait,fifteen_load,runtime,flows} [{five_load,ram,steal_time,one_load,iowait,fifteen_load,runtime,flows} ...]
                        compute stats on specified data
  -G, --all-graphs      graph all data
  -g {five_load,ram,steal_time,one_load,iowait,fifteen_load,runtime,flows} [{five_load,ram,steal_time,one_load,iowait,fifteen_load,runtime,flows} ...], --graphs {five_load,ram,steal_time,one_load,iowait,fifteen_load,runtime,flows} [{five_load,ram,steal_time,one_load,iowait,fifteen_load,runtime,flows} ...]
                        graph specified data

Usage Details: wcbench.sh

Most of the work in WCBench happens in wcbench.sh. It's the bit that directly wraps CBench, automates CBench/ODL installation, collects system stats, starts/stops ODL, and runs CBench against ODL.

In more detail, the wcbench.sh script supports:

• Trivially cloning, building and installing CBench via the oflops repo.
• Changing a set of CBench params (MS_PER_TEST, TEST_PER_SWITCH and CBENCH_WARMUP) to easily set the overall length of a CBench run in minutes. Long CBench runs typically produce results with a lower standard deviation.
• Running CBench against an instance of OpenDaylight. The CBench and ODL processes can be on the same machine or different machines. Change the CONTROLLER_IP and CONTROLLER_PORT variables in wcbench.sh to point CBench at the correct ODL process. To run against a local ODL process that's on the default port, set CONTROLLER_IP="localhost" and CONTROLLER_PORT=6633. To run CBench against a remote ODL process, set CONTROLLER_IP to the IP address of the machine running ODL and CONTROLLER_PORT to the port ODL is listening on. Obviously the two machines have to have network connectivity with each other. Additionally, since WCBench connects to the remote machine to pull system stats, the remote machine needs to have sshd running and properly configured. The local machine should have its ~/.ssh/config file and public keys setup such that ssh $SSH_HOSTNAME works without a password or RSA unknown-key prompt. To do this, setup something like the following in ~/.ssh/config:

Host cbench
    Hostname 209.132.178.170
    User fedora
    IdentityFile /home/daniel/.ssh/id_rsa_nopass
    StrictHostKeyChecking no

As you likely know, ssh-copy-id can help you setup your system to connect with the remote box via public key crypto. If you don't have keys setup for public key crypto, google for guides (very out of scope). Finally, note that the SSH_HOSTNAME var in wcbench.sh must be set to the exact same value given on the Host line above.

• Trivially installing/configuring ODL from the last successful build (via an Integration team Jenkins job).
• Pinning the OpenDaylight process to a given number of CPU cores. This is useful for ensuring that ODL is properly pegged, working as hard as it can with given resource limits. It can also expose bad ODL behavior that comes about when the process is pegged.
• Running OpenDaylight and issuing all of the required configurations.
• Stopping the OpenDaylight process. This is done cleanly via the ./bin/stop script, not kill or pkill.
• Cleaning up everything changed by the wcbench.sh script, including deleting ODL and CBench sources and binaries.

Usage Details: loop_wcbench.sh

The loop_wcbench.sh script is a fairly simple wrapper around wcbench.sh ("I hear you like wrappers, so I wrapped your wrapper in a wrapper"). Its reason for existing is to enable long series of repeated WCBench runs. As described in the WCBench Results section, these results will be stored in a CSV file and can be analyzed with stats.py, as described in the Usage Details: stats.py section. Doing many WCBench runs allows trends over time to be observed (like decreasing perf or increasing RAM). More results can also yield more representative stats.

In more detail, the loop_wcbench.sh script supports:

• Running WCBench against ODL a given number of times, without restarting ODL between runs. This test revealed the perf degradation over time described in bug 1395.
• Running WCBench against ODL a given number of times, restarting ODL between runs. This acted as a control when finding bug 1395, as restarting ODL between runs mitigated perf decreases.
• Pass run length info to WCBench, causing WCBench runs to last for the given number of minutes. Note that longer runs seem to result in lower standard deviation flows/sec results.
• Pin ODL to a given number of processors. This is basically a thin hand-off to wcbench.sh. As mentioned above, pinning ODL allows it to be tested while the process is properly pegged.

Usage Details: stats.py

The stats.py script parses the output of wcbench.sh, which is stored in the file pointed at by the RESULTS_FILE variable in wcbench.sh. See the WCBench Results section for more info on the results file. Both pure stats and graphs of results are supported by stats.py.

Any set of names for data points can be given to the -s flag to calculate their stats and to the -g flag to graph them against run numbers. All stats can be computed with ./stats.py -S, just as all graphs can be generated with -G.

Examples are useful:

# CBench flows/sec stats
./stats.py -s flows
{'flows': {'max': 15036,
           'mean': 8958.426,
           'min': 4981,
           'relstddev': 32.032,
           'stddev': 2869.584},
 'sample_size': 115}

# All stats
./stats.py -S
{'fifteen_load': {'max': 0,
                  'mean': 0.62,
                  'min': 0,
                  'relstddev': 0.0,
                  'stddev': 0.0},
 'five_load': {'max': 0,
               'mean': 0.96,
               'min': 0,
               'relstddev': 0.0,
               'stddev': 0.0},
 'flows': {'max': 22384,
           'mean': 22384.52,
           'min': 22384,
           'relstddev': 0.0,
           'stddev': 0.0},
 'iowait': {'max': 0, 'mean': 0.0, 'min': 0, 'relstddev': 0.0, 'stddev': 0.0},
 'one_load': {'max': 0,
              'mean': 0.85,
              'min': 0,
              'relstddev': 0.0,
              'stddev': 0.0},
 'runtime': {'max': 120,
             'mean': 120.0,
             'min': 120,
             'relstddev': 0.0,
             'stddev': 0.0},
 'sample_size': 1,
 'steal_time': {'max': 0,
                'mean': 0.0,
                'min': 0,
                'relstddev': 0.0,
                'stddev': 0.0},
 'used_ram': {'max': 3657,
              'mean': 3657.0,
              'min': 3657,
              'relstddev': 0.0,
              'stddev': 0.0}}

# Create graphs of flows/sec and used RAM stats
./stats.py -g flows ram

Graph results:

WCBench Results

Results from wcbench.sh are stored in the file pointed at by the RESULTS_FILE variable in wcbench.sh. That variable defaults to RESULTS_FILE=$BASE_DIR/"results.csv", which in turn resolves to ~/results.csv by default. As you can guess from the file name, results are stored in CSV format. Note that this format was chosen because it's what's consumed by the Jenkins Plot Plugin, which ODL uses to automatically run a subset of the functionality provided by WCBench against ODL builds.

Note that manually modifying the results file (adding/deleting lines) will cause incorrect run number values.

The data collected by WCBench and stored in the results file for each run includes:

• A run number for each run, starting at 0 and counting up
• The flows/sec average from the CBench run
• Unix time in seconds at the beginning of the run
• Unix time in seconds at the end of the run
• The IP address of the controller
• Human-readable time that the run finished
• The number of switches simulated by CBench
• The number of MAC addresses used by CBench
• The TESTS_PER_SWITCH value passed to CBench
• The duration of each test in milliseconds
• The steal time on the system running ODL at the start of the test
• The steal time on the system running ODL at the end of the test
• The total RAM on the system running ODL
• The used RAM on the system running ODL at the end of a test run
• The free RAM on the system running ODL at the end of a test run
• The number of CPUs on the system running ODL
• The one minute load of the system running ODL
• The five minute load of the system running ODL
• The fifteen minute load of the system running ODL
• The name of the controller under test
• The iowait value at the start of the test on the system running ODL
• The iowait value at the end of the test on the system running ODL

Detailed Walkthrough: Vagrant

A Vagrantfile is provided for WCBench, which allows you to get an OpenDaylight+WCBench environment up-and-running trivially easily. Vagrant also allows folks on otherwise unsupported operating systems (Ubuntu, Debian, Windows) to use WCBench.

If you don't have Vagrant installed already, head over to their docs and get that knocked out.

If you haven't already, you'll need to clone the WCBench repo:

[~]$ git clone https://github.com/dfarrell07/wcbench.git

You can now trivially stand up a VM with OpenDaylight+CBench+WCBench properly configured:

[~/wcbench]$ vagrant up

If this is your first time using the chef/fedora-20 Vagrant box, that'll have to download. Future vagrant ups will use a locally cached version. Once the box is provisioned, you can connect to it like this:

[~/wcbench]$ vagrant ssh
Last login: Mon Nov 17 14:29:33 2014 from 10.0.2.2
[vagrant@localhost ~]$

WCBench, OpenDaylight and CBench are already installed and configured. You can start OpenDaylight like this:

[vagrant@localhost ~]$ cd wcbench/
[vagrant@localhost wcbench]$ ./wcbench.sh -o
Starting OpenDaylight
Will repeatedly attempt connecting to Karaf shell until it's ready
Issued `dropAllPacketsRpc on` command via Karaf shell to localhost:8101
Issued `log:set ERROR` command via Karaf shell to localhost:8101

Run CBench against OpenDaylight like this:

[vagrant@localhost wcbench]$ ./wcbench.sh -r
Collecting pre-test stats
Running CBench against ODL on localhost:6633
Collecting post-test stats
Collecting time-irrelevant stats
Average responses/second: 29486.95

Since the WCBench Vagrant box is headless, you'll want to move the results.txt to a system with a GUI for graphing.

Vagrant hard-links /home/vagrant/wcbench/ to the directory on your local system that contains WCBench's Vagrantfile. Dropping results.txt in /home/vagrant/wcbench/ will therefore move it to your local system for analysis. You can also modify the RESULTS_FILE variable in wcbench.sh to point at /home/vagrant/wcbench/, if you'd like to put it there by default.

# Move results.txt to hard-linked dir
[vagrant@localhost wcbench]$ mv ../results.csv .

# Configure wcbench to create results.txt in hard-linked dir
RESULTS_FILE=$BASE_DIR/wcbench/"results.csv"

You can now generate graphs and stats, as described in the Usage Details: stats.py section.

To run long batches of tests, use loop_wcbench.sh, as described in Usage Details: loop_wcbench.sh.

Once you're done, you can kill OpenDaylight like this:

[vagrant@localhost wcbench]$ ./wcbench.sh -k
Stopping OpenDaylight

Unless you want a fresh WCBench Vagrant box, you can save yourself some time at your next vagrant up by suspending (instead of destroying) the box:

# On my local system
[~/wcbench]$ vagrant suspend
==> default: Saving VM state and suspending execution...

Detailed Walkthrough: Manual

This walkthrough describes how to setup a system for WCBench testing, starting with a totally fresh Fedora 20 Cloud install. I'm going to leave out the VM creation details for the sake of space. As long as you can SSH into the machine and it has access to the Internet, all of the following should work as-is. Note that this process has also been tested on CentOS 6.5 (so obviously should work on RHEL).

I suggest starting by adding the WCBench VM to your ~/.ssh/config file, to allow quick access without having to remember details.

[~]$ vim .ssh/config

Add something like the following:

Host wcbench
    Hostname 10.3.9.110
    User fedora
    IdentityFile /home/daniel/.ssh/id_rsa_nopass
    StrictHostKeyChecking no

You can now SSH into your fresh VM:

[~]$ ssh wcbench
Warning: Permanently added '10.3.9.110' (RSA) to the list of known hosts.
[fedora@dfarrell-wcbench ~]$

You'll need a utility like screen or tmux, so you can start long-running tests, log out of the system and leave them running. My Linux configurations are very scripted, so here's how I install tmux and its configuration file. You're welcome to copy this.

From my local system:

[~]$ rsync ~/.dotfiles/linux_setup.sh wcbench:/home/fedora

That linux_setup.sh script can be found here.

Back on the remote VM:

[fedora@dfarrell-wcbench ~]$ sudo yum update -y; ./linux_setup.sh -t

Go get some coffee, this will take a while.

Once your VM is updated and tmux is installed, drop into a tmux session.

[fedora@dfarrell-wcbench ~]$ tmux new

For the sake of simplicity, I'm going to do an HTTPS clone of the WCBench repo. You may want to setup your SSH info on the VM and clone via SSH if you're going to be contributing (which is encouraged!).

NB: Git was installed for me during the ./linux_setup.sh -t step, as that cloned my .dotfiles repo. If you don't have git, install it with sudo yum install git -y.

[fedora@dfarrell-wcbench ~]$ git clone https://github.com/dfarrell07/wcbench.git
[fedora@dfarrell-wcbench ~]$ ls -rc
linux_setup.sh  wcbench
[fedora@dfarrell-wcbench ~]$ cd wcbench/

Huzzah! You now have WCBench "installed" on your VM. Now, to install CBench and OpenDaylight.

[fedora@dfarrell-wcbench wcbench]$ ./wcbench.sh -ci
CBench is not installed
Installing CBench dependencies
Cloning CBench repo into /home/fedora/oflops
Cloning openflow source code into /home/fedora/openflow
Building oflops/configure file
Building CBench
CBench is installed
Successfully installed CBench
Installing OpenDaylight dependencies
Downloading OpenDaylight Helium 0.2.3
Unzipping OpenDaylight Helium 0.2.3
odl-openflowplugin-flow-services added to features installed at boot
odl-openflowplugin-drop-test added to features installed at boot

Huzzah! You now have CBench and OpenDaylight installed/configured.

You're ready to get started using WCBench. You can start ODL like this:

[fedora@dfarrell-wcbench wcbench]$ ./wcbench.sh -o
Starting OpenDaylight
Will repeatedly attempt connecting to Karaf shell until it's ready
Issued `dropAllPacketsRpc on` command via Karaf shell to localhost:8101
Issued `log:set ERROR` command via Karaf shell to localhost:8101

Here's an example of running a two minute CBench test against OpenDaylight:

[fedora@dfarrell-wcbench wcbench]$ ./wcbench.sh -t 2 -r
Set MS_PER_TEST to 120000, TESTS_PER_SWITCH to 1, CBENCH_WARMUP to 0
Collecting pre-test stats
Running CBench against ODL on localhost:6633
Collecting post-test stats
Collecting time-irrelevant stats
Average responses/second: 22384.52
/home/fedora/results.csv not found or empty, building fresh one

I suggest copying your results.csv file back to your local system for analysis, especially if you want to generate graphs. From my local system:

[~/wcbench]$ rsync wcbench:/home/fedora/results.csv .

You can now generate graphs and stats, as described in the Usage Details: stats.py section.

If you'd like to collect some serious long-term data, use the loop_wcbench.sh script (of course, back on the VM).

[fedora@dfarrell-wcbench wcbench]$ ./loop_wcbench.sh -t 2 -r
# I'm not going to let this run, you get the idea

You can then disconnect from your tmux session with ctrl + a + d, or ctrl + b + d if you're using the standard ~/.tmux.conf. Let this loop run for a few days, then run lots of stats.py commands against it to see all kinds of cool stuff.

Once you're done, you can stop ODL and clean up the CBench and ODL source/binaries.

[fedora@dfarrell-wcbench wcbench]$ ./wcbench.sh -k
Stopping OpenDaylight
[fedora@dfarrell-wcbench wcbench]$ ./wcbench.sh -d
Removing /home/fedora/distribution-karaf-0.2.3-Helium-SR3
Removing /home/fedora/distribution-karaf-0.2.3-Helium-SR3.zip
Removing /home/fedora/openflow
Removing /home/fedora/oflops
Removing /usr/local/bin/cbench

Contributing

Contributions are encuraged! Contributions are encuraged! Contributions are encuraged! <- I can't say this enough.

The best way to contribute code is to jump on an existing GitHub Issue or raise your own, then fork the code, make your changes and submit a pull request to merge your changes back into the main codebase.

Bugs or feature requests should be raised as Issues.

Note that the code is Open Source under a BSD 2-clause license.

Contact

For feature requests, bug reports and questions please raise an Issue. Daniel Farrell is the primary developer of this tool. He can be contacted directly at dfarrell@redhat.com or on IRC (dfarrell07 on Freenode). Prefer public, documented communication like Issues over direct 1-1 communication. This is an Open Source project. Keep the community in the loop.