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From Andres March <ama...@qualcomm.com>
Subject Re: Cassandra on AWS across Regions
Date Wed, 01 Sep 2010 22:18:52 GMT
  I thought you might say that.  Is there some reason to gossip IP 
addresses vs hostnames?  I thought that layer of indirection could be 
useful in more than just this use case.

I still think it is a good idea to have a separate bind vs gossip config 
param.

On 09/01/2010 03:10 PM, Benjamin Black wrote:
> It's not gossiping hostnames, it's gossiping IP addresses.  The
> purpose of Peter's patch is to have the system gossip its external
> address (so other nodes can connect), but bind its internal address.
> As Edward notes, it helps with NAT in general, not just EC2.  Not
> perfect, but a great start.
>
>
> b
>
> On Wed, Sep 1, 2010 at 2:57 PM, Andres March<amarch@qualcomm.com>  wrote:
>> Is it not possible to put the external host name in cassandra.yaml and add a
>> host entry in /etc/hosts for that name to resolve to the local interface?
>>
>> On 09/01/2010 01:24 PM, Benjamin Black wrote:
>>
>> The issue is this:
>>
>> The IP address by which an EC2 instance is known _externally_ is not
>> actually on the instance itself (the address being translated), and
>> the _internal_ address is not accessible across regions.  Since you
>> can't bind a specific address that is not on one of your local
>> interfaces, and Cassandra nodes don't have a notion of internal vs
>> external you need a mechanism by which a node is told to bind one IP
>> (the internal one), while it gossips another (the external one).
>>
>> I like what this patch does conceptually, but would prefer
>> configuration options to cause it to happen (obviously a much larger
>> patch).  Very cool, Peter!
>>
>>
>> b
>>
>> On Wed, Sep 1, 2010 at 1:10 PM, Andres March<amarch@qualcomm.com>  wrote:
>>
>> Could you explain this point further?  Was there an exception?
>>
>> On 09/01/2010 09:26 AM, Peter Fales wrote:
>>
>> that doesn't quite work with the stock Cassandra, as it will
>> try to bind and listen on those addresses and give up because they
>> don't appear to be valid network addresses.
>>
>> --
>> Andres March
>> amarch@qualcomm.com
>> Qualcomm Internet Services
>>
>> --
>> Andres March
>> amarch@qualcomm.com
>> Qualcomm Internet Services

-- 
*Andres March*
amarch@qualcomm.com <mailto:amarch@qualcomm.com>
Qualcomm Internet Services

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