[MOBY-dev] Services in registry

[Edward Kawas]

Hi, 
> I have not really understood this. Why do services require a 
> namespace?

When you register a service, the namespaces are specified for each
input/output. Depending on your client (or if you are using the API), the
namespace information is very easy to determine. In Taverna, this is
available as tooltips. In dashboard, you can get this information from the
'registry browser' when you click on individual services, etc.

Why do services require a namespace? Because it is the namespace and
identifier of an object that uniquely identifies data. Put another way, the
namespace helps narrow the scope of your data. Imagine that someone gave you
data identified by the string "424360". The question now becomes, what is
it? Now when you specify the namespace of "NCBI_gi", we know exactly what it
is and can use it.

Hopefully others can build upon my explanation if it doesn't make sense.

> If I am a novice user and have an aminoacid 
> sequence, how can I find available services for it then? 

Making a findService call to the registry stating that you want all services
that consume AminoAcidSequence. In fact, you probably could also search for
services that consume, FASTA, etc. Here you may or may not specify
namespace. It depends on the type of services that you will be invoking. For
instance, a service that performs blast against the DragonDB may not be what
you want to do if you have some human sequence.

> should not services respond with "namespace is required"?
They should, but they might not. Some older services might return an 'empty
moby data block', die and return stack traces, or perform the service on
your data giving you unexpected results.

Hope ths helps,

Eddie