An application developed for one of my recent projects at TouK involved multiple servers. There was a requirement to ensure failover for the system’s components. Since I had already a few separate components I didn’t want to add more of that, and since there already was a Zookeeper ensemble running - required by one of the services, I’ve decided to go that way with my solution.
Apache ZooKeeper is an invaluable tool for distributed coordination. However, when I began working for Netflix, I found a lot of interest in ZooKeeper but not a lot of experience. A few trials had been done but none of them made it out of the testing sandbox. For that reason, Curator was initially conceived as a way to make ZooKeeper easier to use for non-experts.
Last year I added clustering support to a system I had previously developed for a client. The requirements were to implement automated failover to eliminate a single point of failure and to distribute certain kinds of work among members of the cluster.
Curator Framework: Reducing the Complexity of Building Distributed Systems
Optify’s Digital Marketing Software Platform collects and processes an impressive amount of data on a daily basis. To handle the volume of pageviews, form submissions, lead scoring, email activities, and Optify Connects many of our services are multi-instanced for both high-availability and throughput.
Dataweek Keynote: Large Scale Search, Discovery and Analysis in Action (Slides 23/24)
Presentation given at TriHUG (Triangle Hadoop User Group) on May 22, 2012. Gives a basic overview of Apache ZooKeeper as well as some common use cases, 3rd party libraries, and "gotchas".
Ready to unlock the power of your data? With this comprehensive guide, you’ll learn how to build and maintain reliable, scalable, distributed systems with Apache Hadoop. This book is ideal for programmers looking to analyze datasets of any size, and for administrators who want to set up and run Hadoop clusters.
Eric Pederson, eric@cpextechnology.com, @sourcedelica,
http://sourcedelica.com/blog
Apache ZooKeeper is an invaluable component for serviceoriented architectures. It effectively solves the difficult problem of distributed coordination (i.e. locking, leader selection, etc.). However, it can be tricky to use correctly. Curator and Exhibitor were written to make using and operating ZooKeeper easier and less error prone.
Understand the application of apache zookeeper in a distributed environment. Use-case: Keeping metadata, config files in sync in a large geographically distributed environment.
Apache ZooKeeper is a powerful system for managing distributed systems. While ZooKeeper’s power is great, and the developers even provide recipes for common use cases, it is perhaps masked by the extreme flexibility and complexity of the system. Thankfully, the folks at Netflix have implemented many of the aformentioned recipes in their Curator framework. The only lacking bit of Curator is documentation—the wiki has a lot of information, but is inscrutable for a beginner. This post intends to simplify the introduction to using Curator for service discovery.
If you have one or more Zookeeper "multi-tenant" clusters you may want to protect znodes against unwanted modifications.
Apache ZooKeeper Made Simpler with Curator (Thanks, Netflix!)