Introduction to Ozone
Apache Ozone is a scalable, redundant, and distributed object store optimized for big data workloads. Apart from scaling to billions of objects of varying sizes, applications that use frameworks like Apache Spark, Apache YARN and Apache Hive work natively on Ozone object store without any modifications.
HDFS works best when most of the files are large but HDFS suffers from small file limitations. Ozone is a distributed key-value object store that can manage both small and large files alike. Ozone natively supports the S3 API and provides a Hadoop-compatible file system interface. Ozone object store is available in a Cloudera Private Cloud Base deployment.
Ozone storage elements
- Volumes
Volumes are similar to accounts. Volumes can be created or deleted only by administrators. An administrator creates a volume for an organization or a team.
- Buckets
A volume can contain zero or more buckets. Ozone buckets are similar to Amazon S3 buckets. Depending on their requirements, regular users can create buckets in volumes.
- Keys
Each key is part of a bucket. Keys are unique within a given bucket and are similar to S3 objects. Ozone stores data as keys inside buckets.
When a client writes a key, Ozone stores the associated data on DataNodes in chunks called blocks. Therefore, each key is associated with one or more blocks. Within a DataNode, multiple unrelated blocks can reside in a storage container.
Key features of Ozone
- Consistency
Strong consistency simplifies application design. Ozone object store is designed to provide strict serializability.
- Architectural simplicity
A simple architecture is easy to use and easy to debug when things go wrong. The architecture of Ozone object store is simple and at the same time scalable. It is designed to store over 100 billion objects in a single cluster.
- Layered architecture
The layered file system of Ozone object store helps to achieve the scale required for the modern storage systems, . It separates the namespace management from block and node management layer, which allows users to independently scale on both axes.
- Easy recovery
A key strength of HDFS is that it can effectively recover from catastrophic events like cluster-wide power loss without losing data and without expensive recovery steps. Rack and node losses are relatively minor events. Ozone object store is similarly robust in the face of failures.
- Open source in Apache
The Apache Open Source community is critical to the success of Ozone object store. All Ozone design and development are being done in the Apache Hadoop community.
- Interoperability with Hadoop ecosystem
Ozone object store is usable by the existing Apache Hadoop ecosystem and related applications like Apache Hive, Apache Spark and traditional MapReduce jobs.
