Manta Filesystem for Hadoop
Introduction
This project provides a Hadoop FileSystem for the open source Manta object store. Unlike other object stores, Manta is strongly consistent and uses a hierarchical file system (like a Unix filesystem) to organize file storage whereas S3/Swift use a key/value system. This model aligns closely with the Hadoop Filesystem model and it leaves us with very few divergences from the default behavior.
Quirks / Divergences
- There is no HDFS functionality natively implemented. All files are accessed via network data transfer.
- Manta URIs take the form of
manta:///user.name/stor/path/to/file - Configuration can be done using Hadoop configuration parameters, Java system properties or environment variables.
- Append is not supported.
- Truncate is only supported for truncating a file to zero bytes.
- Checksums are performed using md5.
- Checksums for portions of large files are done remotely using Manta jobs.
- Disk space use statistics are based on usage reports which aren't updated instantaneously.
- Globally the default replication factor is 2.
- No assumptions about blocksize are made.
- setWriteChecksum() isn't supported yet.
Run Requirements
- Java 8
- Hadoop 2.8.0
- A running instance of the Manta object store (available on the public cloud)
Build Requirements
- Java 8
- Maven 3.0+
Configuration
You will need to have the public/private keys needed to access Manta on the machine in which Hadoop is running. It is often best to verify that these keys are setup correctly using the Node.js Manta CLI.
Configuration will be done using the Hadoop configuration files or environment variables. Refer to the table below for the available configuration options.
Configuration Parameters
Configuration used are the same as Java Manta Client SDK. Hadoop-specific property keys use the same keys as system properties within the Java Manta SDK.
Installation
Please refer to the following guides for installing the Manta Filesystem for Hadoop on different Hadoop ecosystem applications.
License
The Manta Filesystem for Hadoop is licensed under the Apache 2.0 license.