hbase-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Michael Dagaev <michael.dag...@gmail.com>
Subject Re: Question on region server/data node restart
Date Tue, 24 Feb 2009 14:49:56 GMT
Thanks, now it is clear.

However, if a region server is down, it takes a lot of time to retry first,
to rescan the META region when the retries fail, rescan ROOT, etc. to
get eventually to another region server, which will handle the request.
Is it correct ?

On Tue, Feb 24, 2009 at 4:36 PM, Jean-Daniel Cryans <jdcryans@apache.org> wrote:
> This is why we have a META table, it holds the location info. See
> http://wiki.apache.org/hadoop/Hbase/HbaseArchitecture#client
>
> J-D
>
> On Tue, Feb 24, 2009 at 9:28 AM, Michael Dagaev <michael.dagaev@gmail.com>wrote:
>
>> Thanks, Jean-Daniel.
>>
>> I did run hbase-daemon stop regionserver and start regionserver
>> and saw the client retrying to connect to the restarted region server.
>>
>> How does it know to connect to another region server ? Maybe it stops
>> retrying, asks master, and get another region server to connect to.
>> Is it correct ?
>>
>> Thank you for your cooperation,
>> M.
>>
>> On Tue, Feb 24, 2009 at 3:56 PM, Jean-Daniel Cryans <jdcryans@apache.org>
>> wrote:
>> > Michael,
>> >
>> > Regards stopping those nodes, do it using hadoop-daemon/hbase-daemon to
>> stop
>> > them cleanly. Requests from the clients will not "fail", they will simply
>> be
>> > told to look elsewhere for the regions they have in cache. Unless you
>> only
>> > have 1 region server...
>> >
>> > Regards starting the nodes, apart from the usual
>> hadoop-daemon/hbase-daemon,
>> > no.
>> >
>> > J-D
>> >
>> > On Tue, Feb 24, 2009 at 8:50 AM, Michael Dagaev <
>> michael.dagaev@gmail.com>wrote:
>> >
>> >> Hi, all
>> >>
>> >>     As I understand, I can stop a region server and a data node in a
>> >> cluster
>> >> "semi-transparently" for clients, i. e. the requests handled  by the
>> >> region server
>> >> at that time will fail, but cluster will be working.
>> >>
>> >> If I start the data node and region server  I do not have to do anything
>> to
>> >> make
>> >> them work.
>> >>
>> >> Is it correct ?
>> >>
>> >> Thank you for your cooperation,
>> >> M.
>> >>
>> >
>>
>

Mime
View raw message