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

Switch to Threaded View
MapReduce >> mail # user >> SequenceFile syncFs behavior?

Copy link to this message
Re: SequenceFile syncFs behavior?
Hi Thanh Do,

SequenceFile.Writer.syncFs() in 2.x and 2.x-based releases, is
deprecated in favor of hsync() and hflush() new methods but internally
calls hflush itself, so its behavior is the same with regards to
durability as it was before (new metadata entries are created and the
buffer is flushed).

HBase has mechanisms to detect the right method to call (via
reflection) - see the SequenceFileLogWriter#getHFlush(…) method for

On Thu, Nov 1, 2012 at 11:09 PM, Thanh Do <[EMAIL PROTECTED]> wrote:
> Hi all,
> Could somebody clarify me the behavior of SequenceFile.syncFs(). From the
> source, I saw this function is deprecated, and hsync() or hflush() is
> recommended? However, it seems like current stable release of HBase (0.94)
> or the cloudera distribution (4.0) uses syncFs for its HLog file.
> Would syncFs() guarantee data durability?
> I am using hadoop 2.0.
> Many thanks,
> Thanh Do

Harsh J