parrot_run_hdfs - run a program in the Parrot virtual file system with HDFS client setup


parrot_run_hdfs [parrot_options] program [program_options]


parrot_run_hdfs runs an application or a shell inside the Parrot virtual filesystem.

HDFS is the primary distributed filesystem used in the Hadoop project. Parrot supports read and write access to HDFS systems using the parrot_run_hdfs wrapper. The command checks that the appropriate environmental variables are defined and calls parrot_run. See parrot_run(1).

In particular, you must ensure that you define the following environmental variables:

Based on these environmental variables, parrot_run_hdfs will attempt to find the appropriate paths for and These paths are stored in the environmental variables LIBJVM_PATH and LIBHDFS_PATH, which are used by the HDFS Parrot module to load the necessary shared libraries at run-time. To avoid the startup overhead of searching for these libraries, you may set the paths manually in your environment before calling parrot_run_hdfs, or you may edit the script directly.

Note that while Parrot supports read access to HDFS, it only provides write-once support on HDFS. This is because the current implementations of HDFS do not provide reliable append operations. Likewise, files can only be opened in either read (O_RDONLY) or write mode (O_WRONLY), and not both (O_RDWR).

For complete details with examples, see the Parrot User's Manual


See parrot_run(1) for option listing.



parrot_run_hdfs returns the exit status of the process that it runs. If parrot_run_hdfs is unable to start the process, it will return non-zero.


To access a single remote HDFS file using cat:
% parrot_run_hdfs cat /hdfs/server:port/foo
You can also run an entire shell inside of Parrot, like this:
% parrot_run_hdfs bash
% cd /hdfs/server:port/
% ls -la
% cat foo


The Cooperative Computing Tools are Copyright (C) 2003-2004 Douglas Thain and Copyright (C) 2005-2015 The University of Notre Dame. This software is distributed under the GNU General Public License. See the file COPYING for details.


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