Home | About | Sematext search-lucene.com search-hadoop.com
 Search Hadoop and all its subprojects:

Switch to Threaded View
Hadoop, mail # user - HDFS 1.1.0 - File Append


Copy link to this message
-
Re: HDFS 1.1.0 - File Append
Harsh J 2013-08-06, 15:59
HBase does not use append(…) anywhere. It only syncs(…) over its WAL stream
and although sync(…) was an API. Append on 1.x is pretty much broken for
various edge cases and therefore also marked unsupported. If you need
Flume's append usage to work reliably well, you will need to use a 2.x
based HDFS.
On Tue, Aug 6, 2013 at 6:48 PM, Thomas Stidsborg Sylvest <
[EMAIL PROTECTED]> wrote:

>  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 ****
>
>  ****
>
> [EMAIL PROTECTED] ****
>
>  ****
>    ------------------------------
>
> ****
>
> Danske Commodities A/S
> Vaerkmestergade 3
> DK-8000 Aarhus C
>
> http://www.danskecommodities.com ****
>
> ** **
>
> [image: Visit DC on Linkedin]<http://www.linkedin.com/company/danske-commodities>
> ****
>
>  ****
>
> [image: Visit DC on facebook] <http://www.facebook.com/Danske.Commodities>
> ****
>
>  ****
>
> [image: Download my vCard]<http://emailsignature.danskecommodities.com/tss.vcf>
> ****
>
> Danske Commodities e-mail policy
> <http://www.danskecommodities.com/About/Privacy>****
>

--
Harsh J