Apache Hadoop HttpFS is a service that provides HTTP access to HDFS.

HttpFS has a REST HTTP API supporting all HDFS File System operations (both read and write).

Common HttpFS use cases are:

• Read and write data in HDFS using HTTP utilities (such as curl or wget) and HTTP libraries from languages other than Java (such as Perl).
• Transfer data between HDFS clusters running different versions of Hadoop (overcoming RPC versioning issues), for example using Hadoop DistCp.
• Read and write data in HDFS in a cluster behind a firewall. (The HttpFS server acts as a gateway and is the only system that is allowed to send and receive data through the firewall).

HttpFS supports Hadoop pseudo-authentication, HTTP SPNEGO Kerberos, and additional authentication mechanisms via a plugin API. HttpFS also supports Hadoop proxy user functionality.

The webhdfs client file system implementation can access HttpFS via the Hadoop filesystem command (hadoop fs), by using Hadoop DistCp, and from Java applications using the Hadoop file system Java API.

The HttpFS HTTP REST API is interoperable with the WebHDFS REST HTTP API.

For more information about HttpFS, see http://archive.cloudera.com/cdh5/cdh/5/hadoop/hadoop-hdfs-httpfs/index.html.