I agree with Mark. HBase starts the built in ZK support on the nodes that are 
listed in the quorum. That is why it works as Mark says when you add the 
ejabber host. 

What is broken is your job config. For some reason you do not seem to have the 
right config in your jar as it tries to connect to localhost.  Fix that config 
and it should work. 

An idea, print out the config in your code to see what you get during the MR 
job run. That may help you verify what is going on.

Note, just because you have a hbase-site.xml on your nodes does NOT mean the MR 
job picks it up! It must be on the class path for the MR task!

Lars

On Nov 22, 2010, at 7:45, Mark Jarecki <[email protected]> wrote:

> Hi, 
> 
> I'm completely new to HBase and have some questions regarding cell 
> timestamps. 
> 
> My questions: Are there practical limitations to the number of versions 
> (timestamps) a cell can have? Can a cell have, say, a million versions? What 
> are the consequences of this many versions to performance and system 
> requirements? Or instead, should composite row keys be used instead as sorted 
> indexes when numbers are this high?
> 
> To illustrate my questions, I'm modelling the messages exchanged between any 
> 2 users on our system. The table is called "messages", the row key is a 
> composite of the two users' ids involved in the message exchange (e.g. 
> "user1:user2"). A column (e.g. "exchanges:message") contains a cell that is 
> regularly updated with the last message between those users. The cell's 
> timestamp is then used in conjunction with Get.setMaxVersions() and 
> Get.setTimeRange() to enable queries such as "Get the messages exchanged 
> between user1 and user2 since 12th October 12:02:02" or "Get the last 25 
> messages exchanged  between user1 and user2" or "Get all messages exchanged  
> between user1 and user2".
> 
> messages :  {
>       …
>       user1:user2 :  {
>               exchanges:message : {
>                       ...
>                       t3: "Not bad",
>                       t2: "How's it going?",
>                       t1: "Hello"
>               }
>       },
>       …
> } 
> 
> Over time, the number of messages exchanged between the 2 users will be 
> substantial - and growing. I'm concerned that cell versioning was NOT 
> intended for this purpose, and there might be a consequences for having, say 
> a million versions of a cell, 
> 
> Thanks in advance.
> 
> Mark

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