Category Archives: ZooKeeper

How-to: Process and Index Medical Images with Apache Hadoop and Apache Solr

Categories: CDH Guest Search Use Case ZooKeeper

Thanks to Karthik Vadla, Abhi Basu, and Monica Martinez-Canales of Intel Corp. for the following guest post about using CDH for cost-effective processing/indexing of DICOM (medical) images.

Medical imaging has rapidly become the best non-invasive method to evaluate a patient and determine whether a medical condition exists. Imaging is used to assist in the diagnosis of a condition and, in most cases, is the first step of the journey through the modern medical system.

Read More

Apache ZooKeeper Resilience at Pinterest

Categories: Guest ZooKeeper

The guest post below was originally authored by Pinterest engineer Raghavendra Prabhu and published by the Pinterest Engineering blog. Being big ZooKeeper fans, we re-publish it here for your convenience. Thanks, Pinterest!

Apache ZooKeeper is an open source distributed coordination service that’s popular for use cases like service discovery, dynamic configuration management and distributed locking. While it’s versatile and useful, it has failure modes that can be hard to prepare for and recover from,

Read More

Meet the Book Authors: Flavio Junqueira and Benjamin Reed on ZooKeeper

Categories: Books Community ZooKeeper

ZooKeeper book

Flavio Junqueira (PMC Chair of the Apache ZooKeeper project and a member of the Systems and Networking Group at Microsoft Research) and Benjamin Reed (PMC Member and Software Engineer at Facebook) are the co-authors of the new O’Reilly Media book ZooKeeper: Distributed Process Coordination. We had a chat with Flavio and Ben recently about the rationale for writing the book, and what it will add to the distributed systems conversation.

What are HBase znodes?

Categories: General HBase ZooKeeper

Apache ZooKeeper is a client/server system for distributed coordination that exposes an interface similar to a filesystem, where each node (called a znode) may contain data and a set of children. Each znode has a name and can be identified using a filesystem-like path (for example, /root-znode/sub-znode/my-znode).

In Apache HBase, ZooKeeper coordinates, communicates, and shares state between the Masters and RegionServers. HBase has a design policy of using ZooKeeper only for transient data (that is,

Read More

Apache ZooKeeper Made Simpler with Curator (Thanks, Netflix!)

Categories: Community ZooKeeper

Our thanks to Jordan Zimmerman, software engineer at Netflix, for the guest post below about the recently announced Apache Curator (incubating) project. 

Apache ZooKeeper (zookeeper.apache.org) is a client/server system for distributed coordination. On the client side, you use the client library (from Java, C/C++, etc.) to connect to the server. The client library exposes APIs that resemble a simple filesystem.

Read More