Service for managing coordination (e.g. configuration information and synchronisation) of distributed and clustered systems. Based on a hierarchical key-value store, with support for things such as sequential nodes (whose names are automatically assigned a sequence number suffix), ephemeral nodes (which only exist whilst their owners session exists) and the ability to watch nodes. Guarantees that all writes are serial and ordered (i.e. all clients will see them in the same order), meaning it's more appropriate for low write high read scenarios. Can run in a high available cluster called an ensemble. Originally an Hadoop sub-project, but graduated to a top level Apache project in January 2011. Java based, still under active development, and used by a range of technologies including Hadoop, Mesos, HBase, Kafka and Solr.
Other Names ZooKeeper Vendors The Apache Software Foundation Type Open Source - Active Last Updated February 2017 - 3.4
Add ons Apache Curator Is packaged by Apache Bigtop, Hortonworks Data Platform, Hortonworks DataFlow, Cloudera CDH, MapR Converged Data Platform, Amazon EMR Is used by Apache Mesos, Chronos, Mesosphere Marathon