When comparing Splunk vs Graylog2, the Slant community recommends Splunk for most people. In the question“What are the best log aggregation & monitoring tools?” Splunk is ranked 8th while Graylog2 is ranked 9th. The most important reason people chose Splunk is:
It's human readable, intuitive, fast and with auto-complete to boot. And if you need more advanced functionality out of your queries, [120+ page search manual](http://docs.splunk.com/index.php?title=Documentation:Splunk:Search:Whatsinthismanual:6.0beta&action=pdfbook) will give you an insight in how much is actually possible.
Ranked in these QuestionsQuestion Ranking
Pro Easy to use, powerful search
It's human readable, intuitive, fast and with auto-complete to boot. And if you need more advanced functionality out of your queries, 120+ page search manual will give you an insight in how much is actually possible.
Pro Widely used
De facto standard for log aggregation, monitoring, analysis and reporting.
Pro Real-time graphs
You can create visualizations that update in real time.
OS X, Linux & Windows are supported. You can also access Splunk from iOS and Android devices.
Pro Free version
With restrictions on log size and devices a free version is available.
Splunk can turn searches into alerts.
Pro Understands data in any format or language
Pro Extendable via a large selection of apps
Additional functionality can be added with over 500 apps.
Pro Scales effortlessly
It is built for enterprise use, meaning it scales easily.
Pro Free and open source
Graylog2 is licensed under GNU GPL v3.
Pro Easy setup
Graylog2 can be quickly installed on any Linux machine running Java 7 via an executable that allows installing and configuring remote dependencies and graylog2 itself via a web interface.
Information and statistics displayed update in real time.
Pro Little maintenance
Pro Great interface
Easy to overview, intuitive and full of explainers.
Pro Server-side functionality can be extended via plug-ins
Pro Streams allow identifying events in real-time and perform actions
Stream allow filtering events in real time and perform action such as issue alerts or forward messages.
Pro Works well with just about any type of logging
Splunk is pretty expensive compared to other solutions.
The interface and service are very antiquated
Con Complex set up process
Con Limited logging protocols support
Graylog2 only has support for syslog and GELF.
Con Self hosted. Difficult to maintain.
Maintenance is very difficult because of the high volume nature of logs.
Con Interface is hard to use
The interface is hard to use, loaded with data, and difficult to understand.