goprobe

goProbe

This package comprises:

• goProbe - A high-througput, lightweight, concurrent, network packet aggregator
• goQuery - CLI tool for high-performance querying of goDB flow data acquired by goProbe
• gpctl - CLI tool to interact with a running goProbe instance (for status and capture configuration)

Conversion tools:

• goConvert - Helper binary to convert goProbe-flow data stored in csv files

Data backends:

• goDB - A small, high-performance, columnar database for flow data (pkg)

As the name suggests, all components are written in Go.

[!WARNING] Migrating to Version 4 - There are breaking changes for:

• the database format
• goProbe's configuration file format
• goProbe's API endpoints
• the JSON results format from goQuery

To convert your existing pre-v4 DB to a v4.x compatible format, please refer to the legacy conversion tool (v4.1 releases only).

Introduction

Today, targeted analyses of network traffic patterns have become increasingly difficult due to the sheer amount of traffic encountered. To enable them, traffic needs to be captured and examined and broken down to key descriptors which yield a condensed explanation of the underlying data.

The NetFlow standard was introduced to address this reduction. It uses the concept of flows, which combine packets based on a set of shared packet attributes. NetFlow information is usually captured on one device and collected in a central database on another device. Several software probes are available, implementing NetFlow exporters and collectors.

goProbe deviates from traditional NetFlow as flow capturing and collection is run on the same device and the flow fields reduced. It was designed as a lightweight, standalone system, providing both optimized low-footprint packet capture and a storage backend tailored to the flow data in order to provide lightning-fast analysis queries.

Quick Start

Refer to the Releases section to install the software suite.

To start capturing, configure goProbe. To query data produced by it, run goQuery. To query across a fleet of hosts, deploy global-query.

goDB

The database is a columnar block-storage. The raw attribute data is captured in .gpf (goProbe file) files.

goDB is a package which can be imported by other go applications.

The .gpf File Structure

The database has two built-in partition dimensions: interfaces and time. These were chosen with the goal to drastically reduce the amount of data that has to be loaded during querying. In practice, most analyses are narrowed down to a time frame and a particular interface.

Time partitioning is done in two steps: per day, and within the files, per five minute intervals. The location of flow data for these intervals is specified (amongst other properties) in the .meta files.

.meta file

The .meta file can be thought of as a partition-index and a layout for how the data is stored. Next to storing the timestamps and positions of blocks of flow data, it also captures which compression algorithm was used and provides sizing information for block decompression.

The .meta files are vitally important and - if deleted, corrupted or modified in any way - will result in failed data reading for the day of data.

Compression

goDB natively supports compression. The design rationale was to sacrifice CPU cycles in order to decrease I/O load. This has proven to drastically increase performance, especially on queries involving several days and a high number of stored flow records.

Supported compression algorithms are:

• lz4
• zstd
• None (not recommended)

Check encoder.go for the enumeration of supported compression algorithms and the definition fo the Encoder interface. Compression features are available by linking against system-level libraries (liblz4 and libzstd, respectively, so if CGO is used (default) those must be available at runtime and consequently their development libraries are required if the project is build from source).

Alternatively, native Go implementations can be used if CGO is unavailable or by disabling individual or all C library dependencies (in favor of their respective native implementations) by means of the following build overrides:

All of the above can be combined arbitrarily.

[!WARNING] Depending on OS / architecture using native compression can incur a significant performance penalty (in particular for write operations). While allowing for greater portability / ease of use it is not recommended in heavy load / throughput production environments.

Bash autocompletion

goQuery has extensive support for bash autocompletion. To enable autocompletion, you need to tell bash that it should use the goquery_completion program for completing goquery commands. How to do this depends on your distribution. On Debian derivatives, it is recommended to create a file goquery in /etc/bash_completion.d with the following contents:

_goquery() {
    case "$3" in
        -d) # the -d flag specifies the database directory.
            # we rely on bash's builtin directory completion.
            COMPREPLY=( $( compgen -d -- "$2" ) )
        ;;

        *)
            if [ -x /usr/local/share/goquery_completion ]; then
                mapfile -t COMPREPLY < <( /usr/local/share/goquery_completion bash "${COMP_POINT}" "${COMP_LINE}" )
            fi
        ;;
    esac
}

Supported Operating Systems

goProbe is currently set up to run on Linux based systems only (this might change in the future). Tested versions and their system level library dependencies include (but are most likely not limited to):

• Debian >= 7.0 [=> liblz4-1,libzstd1]
• Fedora >= 28 [=> lz4-libs,libzstd]
• Ubuntu >= 14.04 [=> liblz4-1,libzstd1]
• Alpine >= 3.14 [=> lz4-dev,zstd-dev]

Authors & Contributors

• Lennart Elsen
• Fabian Kohn
• Lorenz Breidenbach
• Silvan Bitterli

This software was initially developed at Open Systems AG in close collaboration with the Distributed Computing Group at the Swiss Federal Institute of Technology.

This repository has been forked off the Open Systems repository end of 2018 and has now been detached as a standalone project (September 2020). Bug fixes and development of new features is done in this repository.

It has undergone an almost complete re-write with version 4 in 2023.

Bug Reports & Feature Requests

Please use the issue tracker for bugs and feature requests (or any other matter).

Make sure to branch off the main branch with your feature branch.

License

See the LICENSE file for usage conditions.