So I have now found some answers to some of these, but one question still remains:
On Fri, 6 Sep 2013 23:29:51 +0100 Paul "LeoNerd" Evans <leon...@leonerd.org.uk> wrote: > * The "system.peers" table identifies peers only by their IP address, > not including the port number, whereas TOPOLOGY and STATUS_CHANGE > messages include a port. > > What happens if there is more than one copy of a node using the > same IP address? This can't happen, as the IP address alone is used by Gossip to identify the nodes. > How do I know which TCP port I can use to > communicate CQL with a given peer? It's highly discouraged to use heterogeneous TCP ports for CQL, so in practice they'll all be the same. > * The "system.peers" table doesn't contain any information giving the > current availability status of the nodes, so I don't know if they > are initially up or down. > > I can just presume all the known nodes are up until I try > connecting to them - in any case, it could be that Cassandra knows > of the existence of nodes that for some reason my client can't > connect to, so I'd have to handle this case anyway. But it feels > like that hint should be there somewhere. This question still outstanding. > * The "system.peers" table doesn't include the actual node I am > querying it on. > > Most of the missing information does appear in the "system.local" > table, but not the address. The client does know /an/ address it > has connected to that node using, but how can I be sure that this > address is the one that will appear in the "peers" list on other > nodes? It's quite common for a server to have multiple addresses, > so it may be that I've connected to some address different to that > which the other nodes know it by. Turns out it will only accept connections on the IP address it's using for its peers anyway, so this should be fine. -- Paul "LeoNerd" Evans leon...@leonerd.org.uk ICQ# 4135350 | Registered Linux# 179460 http://www.leonerd.org.uk/
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