Deprecated

This tool is deprecated, and should not be used with Sonar v2 instances. Please use the v2 poller instead.

Sonar Poller

This poller is designed to collect network data and return it to your Sonar instance. You can deploy multiple pollers in a variety of locations to distribute polling, or to gather data from remote network locations.

Requirements

The poller requires a 64bit x86 CPU. At least 2 cores and 4GB of RAM is recommended - assigning more cores will help with rapid polling to a degree. The poller is mostly built in PHP and has been tested on Ubuntu Linux 16.04.

Installation & Setup

This poller should run on most versions of Linux, although the instructions here are tailored to Ubuntu 16.04 64bit. If in doubt, use Ubuntu 16.04 64bit!

If you are not familiar with Linux, I strongly suggest using Ubuntu 16.04 64bit, as you will need to determine how to install the necessary packages detailed below yourself if you use another distribution.

You will need to install the following packages to use this poller - you can use the command below to install them all on Ubuntu 16.04.

sudo apt-get install php7.0-cli php-zip php-snmp php-sqlite3 php-bcmath php-mbstring php-dom git fping snmp redis-server monit ntp snmp-mibs-downloader

If you are using another distribution, you will need the following packages:

• PHP 7.x with the CLI, ZIP, SNMP, SQLite3, BCMath, MBString, and DOM packages. This poller will not work with any version of PHP prior to 7.x.
• git
• FPing 3.x or higher
• net-snmp 5.7.x or higher (with the standard MIBs loaded.)
• redis-server
• monit

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Ubuntu 18.04 is not recommended, if you can't use Ubuntu 16.04 for whatever reasons, please follow the instructions below to get the poller working.

Note: if you've already installed the newer flavour of these programs, you will need to remove them or start on a fresh image.

Add the following lines to /etc/apt/sources.list

deb http://security.ubuntu.com/ubuntu xenial-security main universe

deb http://security.ubuntu.com/ubuntu xenial-security main

Then run

apt-get update sudo apt-get install php7.0-cli php7.0-zip php7.0-snmp php7.0-sqlite3 php7.0-bcmath php7.0-mbstring php7.0-dom

If you have issues, try installing the older version of redis, as the predis library is reported to have issues with newer versions.

wget http://security.ubuntu.com/ubuntu/pool/universe/r/redis/redis-server_3.0.6-1ubuntu0.4_amd64.deb

dpkg -i redis-server_3.0.6-1ubuntu0.4_amd64.deb

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Once the packages are installed, we can install the poller. First, download the latest poller code by typing git clone https://github.com/SonarSoftwareInc/poller-v1.git. This will clone the existing code into a directory named poller, enter it by typing cd poller. Now, navigate to the releases page and check what the latest tagged release is. You can also type git describe --abbrev=0 to see the latest tag from the command line. Once you've found it, type git checkout tags/{TAG} where {TAG} is the latest tag found (e.g. git checkout tags/1.0.3). Now type php install.php and the installer will setup the poller itself.

Once the install is complete, navigate to your Sonar instance, go to Network > Monitoring > Pollers, and add a new entry for this poller. Select all the subnets you wish this poller to poll. After it is added, copy the API key shown in the poller list - you'll need it in a second.

Once the installer is finished, type sudo -u sonarpoller cp /opt/poller/.env.example /opt/poller/.env and then sudo -u sonarpoller nano -w /opt/poller/.env. Modify the SONAR_URI value to be the full path to your Sonar instance, including https://. Modify the API_KEY value to be the API key you copied from Sonar a moment ago.

Press CTRL+X to exit nano, and save the changes you made.

Testing

You can test the pollers ability to obtain and deliver work by typing sudo -u sonarpoller php /opt/poller/bin/getWork.php. If something is misconfigured, you will receive a message with details about the problem. If you see Obtained work from Sonar, queueing.. then everything is configured correctly.

Upgrading

You can upgrade by updating the repository and checking out the tag you wish to update to. You can also simplify this by using the checkForUpgrades script. To run this, type sudo php /opt/poller/bin/checkForUpgrades.php. You should do this fairly regularly to ensure your poller is up to date.

You can also automate updates by adding an auto-updater file to cron. To do this, copy the automatic cron file by typing sudo cp poller_upgrade /etc/cron.d. This will force the system to check for poller updates every morning, and update if any are available.

Scaling and Advanced Usage

In most scenarios, you can leave all configuration settings at their defaults and have an efficient, fast poller. This section is only for very large networks, or users who wish to tinker!

The poller automatically forks multiple ICMP and SNMP polling processes when running. The quantity of times it forks is defined in the .env file, as ICMP_FORKS and SNMP_FORKS. The default values for these settings are a good fit for most systems.

There are also timeout values set for both ICMP polling and SNMP polling as ICMP_TIMEOUT and SNMP_TIMEOUT, respectively. These values are measured in seconds, and can be a decimal.

If you find that you need to poll more rapidly, there are a few things you can try before deploying additional pollers to split the load.

First, ensure that you have sufficient resources on your system by adding additional CPU cores/RAM. Now you can try scaling the fork settings and timeout settings in order to poll more rapidly. A lower timeout setting will help reduce your polling time if you have a lot of inaccessible devices. A higher fork setting will launch more polling processes, and may help reduce the polling time to a degree.

To test your changes, set DEBUG to true in your .env file, and watch your /var/log/sonar_poller.log file by typing tail -f /var/log/sonar_poller.log. While tailing the log file, editing the .env file and change the appropriate fork/timeout values. The poller will execute every minute, and with debug enabled, will output lines into the log file to let you know when it receives work, and when it completes work. This is a fairly quick way to see how long your ICMP and SNMP polling cycles are taking, and the impact your configuration file modifications are having on speed. Make sure to also keep an eye on your system resources to ensure you're not overloading your polling server.

Also note that increasing the fork values will increase the amount of data that is leaving and being returned to your polling server, so be aware of the load on your network, and the network interface on your polling server while making these changes.

Once you're done making changes, ensure you set DEBUG back to false in your .env file.