On Thu, Nov 11, 2010 at 7:31 AM, Thanh Do wrote:
> Thanks Todd,
>
> In HDFS-6313, i see three API (sync, hflush, hsync),
> And I assume hflush corresponds to :
>
> *"API2: flushes out to all replicas of the block.
> The data is in the buffers of the DNs but not on the DN's OS buffers.
> New reade
Thanks Todd,
In HDFS-6313, i see three API (sync, hflush, hsync),
And I assume hflush corresponds to :
*"API2: flushes out to all replicas of the block.
The data is in the buffers of the DNs but not on the DN's OS buffers.
New readers will see the data after the call has returned.*"
I am still c
Nope, flush just flushes the java side buffer to the Linux buffer
cache -- not all the way to the media.
Hsync is the API that will eventually go all the way to disk, but it
has not yet been implemented.
-Todd
On Wednesday, November 10, 2010, Thanh Do wrote:
> Or another way to rephase my quest
Or another way to rephase my question:
does data.flush and checksumOut.flush guarantee
data be synchronized with underlying disk,
just like fsync().
Thanks
Thanh
On Wed, Nov 10, 2010 at 10:26 PM, Thanh Do wrote:
> Hi all,
>
> After reading the appenddesign3.pdf in HDFS-256,
> and looking at the
Hi all,
After reading the appenddesign3.pdf in HDFS-256,
and looking at the BlockReceiver.java code in 0.21.0,
I am confused by the following.
The document says that:
*For each packet, a DataNode in the pipeline has to do 3 things.
1. Stream data
a. Receive data from the upstream DataNode o
