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Posted to mapreduce-dev@hadoop.apache.org by Ted Yu <yu...@gmail.com> on 2011/05/21 01:41:33 UTC

dynamic configuration changes

Hi,
We're looking at extending the work done in HADOOP-7001 to HBase.

I want to get opinion on providing coarse-grained property reconfig
mechanism. Namely reconfigureProperty()/reconfigurePropertyImpl() only
notifies single property change.
Normally a class would be interested in more than one reconfigurable
property. e.g.
    String hostname = DNS.getDefaultHost(
      conf.get("hbase.master.dns.interface", "default"),
      conf.get("hbase.master.dns.nameserver", "default"));

I wonder if it is useful to enhance the methods to notify multiple property
changes - more precisely the properties returned by
getReconfigurableProperties().

Thanks

Re: dynamic configuration changes

Posted by Ted Yu <yu...@gmail.com>.
I logged:
https://issues.apache.org/jira/browse/HADOOP-7319

Please comment so that I get to know what I might have missed.

Thanks

On Fri, May 20, 2011 at 10:44 PM, Ted Yu <yu...@gmail.com> wrote:

> The two properties cited below would ideally be updated atomically,
> requiring some kind of locking.
>
> One more reason for coarse-grained property reconfig is that it can reduce
> lock contention updating related properties.
>
> Cheers
>
>
> On Fri, May 20, 2011 at 4:41 PM, Ted Yu <yu...@gmail.com> wrote:
>
>> Hi,
>> We're looking at extending the work done in HADOOP-7001 to HBase.
>>
>> I want to get opinion on providing coarse-grained property reconfig
>> mechanism. Namely reconfigureProperty()/reconfigurePropertyImpl() only
>> notifies single property change.
>> Normally a class would be interested in more than one reconfigurable
>> property. e.g.
>>     String hostname = DNS.getDefaultHost(
>>       conf.get("hbase.master.dns.interface", "default"),
>>       conf.get("hbase.master.dns.nameserver", "default"));
>>
>> I wonder if it is useful to enhance the methods to notify multiple
>> property changes - more precisely the properties returned by
>> getReconfigurableProperties().
>>
>> Thanks
>>
>
>

Re: dynamic configuration changes

Posted by Ted Yu <yu...@gmail.com>.
The two properties cited below would ideally be updated atomically,
requiring some kind of locking.

One more reason for coarse-grained property reconfig is that it can reduce
lock contention updating related properties.

Cheers

On Fri, May 20, 2011 at 4:41 PM, Ted Yu <yu...@gmail.com> wrote:

> Hi,
> We're looking at extending the work done in HADOOP-7001 to HBase.
>
> I want to get opinion on providing coarse-grained property reconfig
> mechanism. Namely reconfigureProperty()/reconfigurePropertyImpl() only
> notifies single property change.
> Normally a class would be interested in more than one reconfigurable
> property. e.g.
>     String hostname = DNS.getDefaultHost(
>       conf.get("hbase.master.dns.interface", "default"),
>       conf.get("hbase.master.dns.nameserver", "default"));
>
> I wonder if it is useful to enhance the methods to notify multiple property
> changes - more precisely the properties returned by
> getReconfigurableProperties().
>
> Thanks
>