When comparing Kafka vs Splunk, the Slant community recommends Splunk for most people. In the question“What are the best log management, aggregation & monitoring tools?” Splunk is ranked 8th while Kafka is ranked 10th. 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 Optimized for performance
Kafka is optimized for supporting a huge number of users.
Pro Native mirroring support
Kafka has native support for mirroring.
Pro Native compression support
Kafka has native support for compression.
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 Scales effortlessly
It is built for enterprise use, meaning it scales easily.
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.
Con Java is a resource hog
Java is a resource hog, making this far too slow unless you have money to throw at multiple servers with 1/2TB of ram.
Con Need Zookeeper
Kafka can only work with Zookeeper
Splunk is pretty expensive compared to other solutions.
The interface and service are very antiquated
Con Seriously SLOW ingest
Their docs and sales say it will ingest up to 20k EPS, but reality is more like 1k eps per server.