Re: [infinispan-dev] [infinispan-internal] Unstable Cluster
On 3/6/13 1:33 PM, Dan Berindei wrote:
On Tue, Mar 5, 2013 at 6:04 PM, Bela Ban <bban(a)redhat.com
<mailto:bban@redhat.com>> wrote:
On 3/5/13 3:30 PM, Erik Salter wrote:
> Hi guys,
>
> Keep in mind that some of your customers may have built queries
and indexes
> on cluster names on top of very expensive analytics engines.
Well, if they use their own naming (JChannel.setName()), no problem.
Bela, you mean GlobalConfiguration.transport().nodeName(), right? :)
Probably, yes
But I've said (many times) that relying on node names is a
*bad thing* !
Node names are syntactic sugar, and there may not be a name associated
with a node, and then it has to be fetched dynamically, using an ARP
like protocol.
So if a thread logging the name of a node it may trigger an "RPC" and
it'll block until it gets a response?
That doesn't sound right...
No, this is only done for the UUID/physical-address mapping, but not for
the logical name.
If someone wanted to add information to an address, then the way
to do
it would be to use an AddressGenerator and return subclasses of UUID,
e.g. PayloadUUID.
I think Erik just wants the logs to contain the actual host names, so
that they match with the logs from other sources. Using a PayloadUUID
and sending the host name with every message would be overkill for that.
Fair enough - with the caveat that the logical name *may* not always be
available, e.g. if you start many nodes concurrently. If he can work
with this, or around it, no problem. Yes, using the logical name causes
no overhead for every address, contrary to PayloadUUID.
--
Bela Ban, JGroups lead (http://www.jgroups.org)