[Beowulf] Announcing nettee 0.1.4

David Mathog mathog at mendel.bio.caltech.edu
Tue May 3 13:35:32 PDT 2005

nettee is a network "tee" program derived from Felix Rauch Valenti's
dolly program.

nettee can create a network daisychain
which passes a data stream along at full network bandwidth while
(optionally) writing the data to each local node.  If your disks
are slow and the data larger than disk cache then it will only
move data as fast as the disks can be written.  Otherwise speeds
up up to 11.3 Mb/sec were observed (100baseT).  So nettee
is useful for distributing large files or in conjunction with
SystemImager to clone nodes.

Additionally nettee can be configured to create a command chain
that lets the same command run on every node in the chain
with only a .01s delay from the time it is issued to the time
it runs on all nodes (chain of length 20, 100baseT switched
network.)  The downside - stdout and stderr are usually lost
or unusable.

Example scripts showing a few uses for the program are
provided in the distribution.  Instructions for using nettee
with SystemImager are found in the README.TXT file.

Look here for more info:


The program is still in alpha.  It has been pretty reliable for me
so far but your mileage may vary.

And yes, I did look at netcat.  In simple tests nettee moves
large blocks of data about 25% faster than netcat does.  I have
not attempted to figure out why nettee is faster.


David Mathog
mathog at caltech.edu
Manager, Sequence Analysis Facility, Biology Division, Caltech

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