Database Reference
In-Depth Information
To combat that problem, Yahoo! and other companies began to develop
coordination tools that act as a service rather than as a component of a
piece of software. This resulted in the development of ZooKeeper and its
eventual contribution to the Apache project. The success of this approach is
evident: Most of the distributed software used in this topic uses ZooKeeper
for configuration and coordination. Other systems, such as etcd, are now
being developed, but ZooKeeper remains the most popular by far.
The next few chapters of this topic put ZooKeeper to work by discussing
distributed systems. The heaviest user is the Kafka project, a data motion
system discussed in Chapter 4. It is also heavily used to coordinate
stream-processing applications such as Storm and Samza, both of which use
the project.
ZooKeeper is also useful in end-user applications. It can help to manage
a distributed state such as data schemas. Additionally, it can provide
controlled access to limited shared resources as needed. Its versatility and
usefulness is why it was presented here in such detail.
