Home | About | Sematext search-lucene.com search-hadoop.com
 Search Hadoop and all its subprojects:

Switch to Threaded View
HBase, mail # dev - Can a server function make a rpc call to the corresponding client


Copy link to this message
-
RE: Can a server function make a rpc call to the corresponding client
Anoop Sam John 2012-06-28, 16:35
Hi
     You can see RegionObserver Interface.  You need to implement this interface and plugin the same to RSs.
[U can also extend BaseRegionObserver class]
CP contains hook points which the RS contact during different actions happening at the server. Like put, delete. There are pre and post hooks.  What ever the action u want to happen during this time u can add in appropriate hook methods.  
After implementing the interface you can plugin the same into RS by configuring the fully qualified class name of of your implementation class in hbase-default.xml file

The config param key is hbase.coprocessor.user.region.classes

Note : There is possible to write CP for Master also. But you might need it at RS side only.  Hope this helps u..  You can read HBase book for more details

-Anoop-
________________________________________
From: Dishant A [[EMAIL PROTECTED]]
Sent: Thursday, June 28, 2012 8:11 PM
To: [EMAIL PROTECTED]
Subject: Re: Can a server function make a rpc call to the corresponding client

Hi Anoop,

I haven't used co-processor package before but my understanding is that, it
is the client which calls desired region-servers instead of server calling
the client. Can you please explain how a server-side function can
call/instantiate co-processor.

Thanks,
Dishant

On Thu, Jun 28, 2012 at 12:59 AM, Anoop Sam John <[EMAIL PROTECTED]> wrote:

> Hi
>    Can you write your code in a co processor impl? So that server can call
> your code. CP will run at server side.
> I am not sure whether you must come to the client process itself.
>
> -Anoop-
> ________________________________________
> From: Dishant A [[EMAIL PROTECTED]]
> Sent: Thursday, June 28, 2012 6:55 AM
> To: [EMAIL PROTECTED]
> Subject: Re: Can a server function make a rpc call to the corresponding
> client
>
> I am working on developing encrypted hbase storage.
>
> The task I am working on currently requires a temporary key from the client
> to decrypt the value. I cannot pass it during the client to server RPC as
> it will only be known at the time of processing (on server side) so as to
> which key is needed. I need to make a RPC to the client to get that key.
> Can you suggest a way to do it?
>
>
> On Wed, Jun 27, 2012 at 1:44 PM, Jean-Daniel Cryans <[EMAIL PROTECTED]
> >wrote:
>
> > You probably don't want to do that.
> >
> > What are you trying to achieve exactly?
> >
> > J-D
> >
> > On Wed, Jun 27, 2012 at 8:46 AM, Dishant A <[EMAIL PROTECTED]>
> > wrote:
> > > Hi Everyone,
> > >
> > > I am working on a project that requires some information from the
> client
> > at
> > > runtime.
> > >
> > > So I need to make a RPC to the client with some arguments from a server
> > > side function (SingleColumnValueFIlter.java). Can anyone please tell me
> > how
> > > I can do it.
> > >
> > > Thanks,
> > > Dishant
> >
>