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From Thomas Stidsborg Sylvest <...@danskecommodities.com>
Subject HDFS 1.1.0 - File Append
Date Tue, 06 Aug 2013 13:18:38 GMT
Hi,

I am in the process of developing a framework around Hadoop that enables RabbitMQ messages
to be persisted in HDFS. The messages will continuously stream into the system, as they are
stock prices or weather data etc. Unfortunately it looks like I will not be able to append
to a file in HDFS version 1.x.x. as per:

HADOOP-8230. Major improvement reported by eli2 and fixed by eli
Enable sync by default and disable append
Append is not supported in Hadoop 1.x. Please upgrade to 2.x if you need append. If you enabled
dfs.support.append for HBase, you're OK, as durable sync (why HBase required dfs.support.append)
is now enabled by default. If you really need the previous functionality, to turn on the append
functionality set the flag "dfs.support.broken.append" to true.

Link: http://hadoop.apache.org/docs/r1.1.1/releasenotes.html

Could anyone please elaborate on this release note message? Why is it possible for HBase to
append? Can I create a program somehow that is able to safely and robustly append to files?

I am running HortonWorks Windows distribution (that is Hadoop version 1.1.0) on a cluster
of 3 machines.

Many thanks for your help in advance.

Kind Regards,

Thomas

Best regards,











Thomas Stidsborg Sylvest
Software Developer



Mobile:

+45 3141 4831



tss@danskecommodities.com <mailto:tss@danskecommodities.com>




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