Re: [bailey-developers] SF.net SVN: bailey: [10] trunk/src

[Doug C. <cu...@ap...>]

Ning Li wrote:
> None of the host related protocols are there yet. We should decide
> a few things before we add those?
> 1 Should nodes run as threads within a host process or as separate
>    processes on a host? Do we still need a host process in the latter case?

I think we'll at least initially implement these as threads.  I don't 
see many advantages of making these separate processes, and it will 
complicate lots of things.

> 2 In the former case, do we have HostToMasterProtocol and
>    ClientToHostProtocol, or do we have NodeToMasterProtocol and
>    ClientToNodeProtocol, or both sets?

With threads, we don't need both Host and Node protocols, so, unless we 
think it will make implementation cleaner, we should skip this.  Will 
each node have its own thread, or might a single thread host per send 
hearbeats for all nodes, with another thread fetching and applying 
updates, etc.  (Since Lucene itself now multithreads updates, we might 
not want all nodes updating in parallel.)

Given that, I think I'd opt for just HostToMasterProtocol and 
ClientToHostProtocol, with nodes in parameters.  Does that sound 
reasonable to you?

> I changed range to be <long, long> for now. However, a document
> id is of type String, so we have to convert from String to long. It is
> hard if we want to maintain the order of the ids after we convert
> them to longs.

Right.  We need to decide on the bits per point on the ring.  Is 64 
enough?  We also need a Document method to get its ring coordinate. 
This will by default be a hash of the ID string, but we should store it 
in a separate field, so that folks can someday specify it explicitly.

Doug