hbase-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Mohit <mohitsi...@huawei.com>
Subject RE: Even After removing the hdfs blocks from Data Nodes, I could still able to query the table.
Date Mon, 27 Dec 2010 05:04:42 GMT
Hmm, I got it, seen in the RS logs :- flush statements for the region I was
talking about, while closing it, so new DFS blocks got created, but luckily
the flush happened during RS shutdown.

Thanks Todd.

This e-mail and attachments contain confidential information from HUAWEI,
which is intended only for the person or entity whose address is listed
above. Any use of the information contained herein in any way (including,
but not limited to, total or partial disclosure, reproduction, or
dissemination) by persons other than the intended recipient's) is
prohibited. If you receive this e-mail in error, please notify the sender by
phone or email immediately and delete it!

-----Original Message-----
From: Todd Lipcon [mailto:todd@cloudera.com] 
Sent: Friday, December 24, 2010 9:08 PM
To: user@hbase.apache.org; mohitsikri@huawei.com
Subject: Re: Even After removing the hdfs blocks from Data Nodes, I could
still able to query the table.

Hi Mohit,

On Fri, Dec 24, 2010 at 6:15 AM, Mohit <mohitsikri@huawei.com> wrote:

> I created a table say temp via HBase shell and put on entry(row) into
> I then deleted the DFS blocks specific to that particular table from both
> of
> my Data Nodes.
> I confirmed the same by doing ls on table directory under root HBase
> directory for example :- ./hadoop fs -ls /hbase/temp/123456/colfam and
> there
> was no file(data) under this directory.

Deleting HDFS blocks directly on DNs wouldn't have affected the output of fs
-ls.  The fact that you see no data at this point means that you must have
deleted some other files from the DNs (maybe the logs?)

> I then perform scan 'temp', it gave me result, Good Ok, I though the data
> is
> cached in Memstore so I could able to get. No problem so far.
> Yep, it's probably in memstore.

> So I restarted the HBase cluster to clear off the cache, and from the
> mode , I performed scan 'temp' operation and strangely I could able to
> fetch
> the data whatever I have deleted and also the data file was present under
> table directory.

When you restarted HBase, it probably flushed the memstore to the storefile.

> I could able to see the same data , say by doing
> ./hadoop fs -cat /hbase/temp/123456/colfam/4588349323987497
This is the flushed file from above.

Todd Lipcon
Software Engineer, Cloudera

View raw message