Re: [Gluster-devel] RFC - "Connection Groups" concept

[Justin Clift]

On 27/06/2013, at 8:07 PM, Anand Avati wrote:
<snip>
> To figure out which connection a client has to use, we could do auto-discover 
> at the time of GETSPEC depending on which network interface the GETSPEC 
> request is coming in from. We already have per transport client volfiles (one 
> for tcp, one for rdma), and extending it to per network is natural. Today we 
> ask the client to specify the transport type in GETSPEC (e.g "volname.rdma") 
> - but even that can be retired if we start using getsockname() and discover 
> the incoming interface.
> 
> This way the client only specifies the appropriate (routable) mount server IP 
> and everything else is resolved automatically.
> 
> Another approach might be to just store the UUID of the host in the client 
> volfile, as remote-uuid (instead of remote-host option). The client can query 
> the mount server to resolve the UUID to a host at that point in time with a 
> HOSTMAPPER service (like our PORTMAPPER server which maps bricks to ports). 
> This hostmapper can maintain the relationship of all the host UUIDs in the 
> trusted pool to all their respective interface IPs, and use the interface of 
> the incoming mapping request to perform appropriate mapping. When in doubt, 
> it can always return the entire set of IPs of a host (with transport types) 
> and let the client figure out which of those IPs are routable and maybe even 
> autodetect which is the fastest. E.g your server might have both 1g/e and 
> 10g/e, and only some of your clients have 10g/e. In such cases this kind of 
> auto discovery at mount time might be desirable.
> 
> Thoughts?

Interesting idea.  Self-heal traffic between servers could use the same
approach (and same code?) too with this couldn't it?

+ Justin

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