hbase-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Ramkrishna S Vasudevan <ramakrish...@huawei.com>
Subject RE: A question about Hmaster startup.
Date Tue, 19 Apr 2011 04:47:30 GMT

Yes. In Hbase 0.90.2 this change has been done.

The HMaster tries creating the /hbase/hbase.version and when the DN comes up the NN throws
an exception saying AlreadyCreatedException.

so the HMaster is not able to start.


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: Gaojinchao [mailto:gaojinchao@huawei.com] 
Sent: Tuesday, April 19, 2011 9:57 AM
To: user@hbase.apache.org
Subject: Re: A question about Hmaster startup.

My queston is:
If HMaster is started after NN without starting DN in Hbase 090.2 then HMaster is not able
to start due to AlreadyCreatedException for /hbase/hbase.version.
In hbase version 0.90.1, It will wait for data node start up.

I try to dig the code and find the code changes in hbase version 0.90.2 and can't find issue
for this.

发件人: jdcryans@gmail.com [mailto:jdcryans@gmail.com] 代表 Jean-Daniel Cryans
发送时间: 2011年4月19日 11:59
收件人: user@hbase.apache.org
主题: Re: A question about Hmaster startup.

Vague question, I'll try my best answer.

This was committed as part of "HBASE-1816 Master rewrite", and in the
comments I can read:

+ Move fs methods out of HMaster to FSUtils.

And if you you look at FSUtils, you'll see how it's done now.


On Mon, Apr 18, 2011 at 8:48 PM, Gaojinchao <gaojinchao@huawei.com> wrote:
> Why delete this code ?
> // Are there any data nodes up yet?
>    // Currently the safe mode check falls through if the namenode is up but no
>    // datanodes have reported in yet.
>    try {
>      while (dfs.getDataNodeStats().length == 0) {
>        LOG.info("Waiting for dfs to come up...");
>        try {
>          Thread.sleep(wait);
>        } catch (InterruptedException e) {
>          //continue
>        }
>      }
>    } catch (IOException e) {
>      // getDataNodeStats can fail if superuser privilege is required to run
>      // the datanode report, just ignore it
>    }

View raw message