BioMoby Developers Meeting TODO list

API Changes:

1: Storage of xml-lang information in registry is necessary; providers should pay attention to which xml-lang attribute they send to the registry when they register their service/object/etc.
2: not all sub-elements need to be in an object instance. Document the fact that an element that is missing is different from an element that is blank.
3: explicitly say that member articles of an object are allowed to be child types of the registered type. We are now promoting a behaviour for member articles that already existed for the parent objects.
4: support Document style encoding as well as REST as well as the traditional RPC

TO DO’s:

1: Store all incoming registry data as UTF-8 MARK

2: Store the xml-lang of the incoming registry entry, and reproduce it on output from reg. MARK

3: support for async services in jMoby core MARTIN/INB

4: INB is going to propose using endpoint references as part of async (pass references to biiiig data) INB

5: everyone look at how to stream data in Web Services protocol EDDYONE

6: reorganize jMoby CVS so that tests are in a folder off of root. PAUL

7: Mark needs to update CommonSubs object parsing code to allow for missing sub-tags MARK

8: Mark needs to document about missing sub-tags MARK/EDDIE/WENDY

9: Others will look at their parsers to see if they need to be updated EVERYONE

10: Mark needs to update CommonSubs to allow sub-objects to inherit MARK/EDDIE/WENDY

11: Classpath.template should be added to CVS MARTIN

12: Martin is goign to change build process to “ant maven” MARTIN

13: Someone will commit to maven repository (need to get permissions on the existing open-bio maven repository) ALL JAVA DEVELOPERS

14: Java API documentation should either be reduced or shold be split into FULL and CORE – javadoc etc. MARTIN

15: WENDY needs to write an introduction to Moby document that explains what we mean by object, namespace, etc. and the basic behaviour that we are trying to achieve. WENDY

16: Someone (wendy?) needs to take charge of all documentation and FIX IT! Also try to get registry calls in some standard (BNF?) format. Registry API should be all in one document. Use XS3P schema documentation generator. WENDY

17: Martin makes a CPAN release of MoSeS + registry snapshot (one day) EDDIE/MARTIN

18: Mark will explore how feasible it is to register secondary outputs. Will make API change proposal to list. MARK

19: Releases of Moby Perl code should be in CPAN MARK WITH HELP FROM SOMEONE WHO KNOWS

20: Methods for testing services (at various levels) – including sample input/output in the LSID metadata. will become a part of jMoby’s API, and possibly a panel in Dashboard. NEED TO KNOW THE PREDICATE NAMES for this. MARTIN

21: Cleanly split Perl registry from java “stuff”. EDDIE

22: Andreas continues working on registry synchronization… fun fun fun! He will propose to the list, will take advice from community, and decide for himself what he wants to support. ANDREAS

23: Think about the proper way to attribute (e.g. logo’s) and state this in the documentation ANDREAS

24: MobyCentral needs to generate WSDL consistent with Document style encoding MARK/EDDIE

25: Moby Central needs to record the style that a service is provided -> add new fields to the registerService/findService input/output also the LSID metadata -> coordinate this with Feta MARK/EDDIE

26: Moby Central should somehow support registration of REST-style services. We decided that POST must be supported by any REST service. How does this affect WSDL? All REST services must be synchronous (at the moment) MARK/EDDIE

27: Ivan needs to look into support for Async services in REST (someday… manana) INB

28: Authentication -> how should we do it in the various libraries PAUL (Java)/EDDIE (Perl)

29: Paul will jMoby LSID library/API/implementation to get the metadata from service providers PAUL

30: Can we please make a WSDL/XML Schema file for Moby Central EDDIE

BioMoby jMoby developers meeting – hour #1

In attendance:

Mark, Eddie, Wendy, Richard, Ivan, Andreas, Paul, Martin, Mylah

We started with jokes about the danger of having the core Moby developers in the same room of a brick hospital built on top of a geological fault…

Issues that come up:
Atrtribution of data to providers
– set logo?

Should the Object ontology have multiple representations for any given concept?
– e.g. FASTA and DNA Sequence are redundant…
– we need to find a way to encourage object re-use
– we need a “rule-base” to use the SeaHawk transformation rules rather than registering a new Moby object; or do we still need to register a new object?

monitoring Moby usage

If we had a “referrer” that kept track of the previous service that was executed this would go into the service provider logs. We could then set up a service (pull) that Moby Central could use to gather this information from the logs. Alternately, we could “push” from the service as it is executed…

For us as client writers the first step is to ensure that we add the “referer” header… so we gotta do that! Probably the LSID of the previous service?

All in all, this will give us the ability to make the ‘next most popular choice’ very visible in our clients – filtering out the lesser-used services and bringing the cream to the top.

Day two: The future of the Moby protocol

Problem #1: Registry

We have a problem that the registry is a mishmash of Perl and Java. The RESOURCES script is problematic since it is used by MOBY::Central to generate the RDF that is passed back from a registerService call. This needs to be Perlified. The agent is NOT a web script so that isn’t a problem. The isAlive “pinger” can be ported to Perl, but since it uses threads it will run slower in Perl than it did in Java. In any case, the entire registry can be written in Perl.

Decision: write a CPAN distribution
Decision: write an installer

Martin suggests “Perl Hacks” book as a must-read.

Problem #2: Services

need to support legacy. All 1300 services are currently RPC, so we have to keep that.

We need to add a field in the registry to indicate which style of encoding is being used. We prefer document-literal-wrapped.

Separate field in the database, API, LSID metadata, … field called “style”. Currently have a field called “category”, which has values “moby”, “moby-async”, and unofficially “post’. Separate “style” from “category”? Probably a good idea.

Tell Wendy that we need to put the async protocol up on the website.

IFF we provide “correct” WSDL will that make people happier? Maybe… we can provide WSDL in ~90% of the cases (though NOT for validation!)

Burning issue is that we don’t have XML Schema. Why? Because we allow more specialized objects to be passed into a service (and problems with HAS relationships). The world is moving to RDF, and RDF also cannot be expressed in XML schema, so the “political” arguments against Moby are going to eventually die-out.

One problem is that we pass a full XML document in our SOAP:body. If we use document encoding, we will need to strip the XML header which has other encoding info that we want to have… and the message will have to be parsed twice – once by the SOAP libraries and once by our Moby libraries (because we don’t have an XML schema to give to teh SOAP libraries to unmarshal the objects) and that will give us unacceptable overheads.

If we move to a REST style, then we don’t have these problems, but we don’t get any (what?) advantages of WSDL or SOAP.

We can use string encoding and send Moby messages exactly as we do now in teh body of a document-style SOAP message. No advantages of the SOAP libraries, but also no overhead of double-parsing of teh message (exactly as we do with the Moby XML-RPC style right now)

Conclusion: INB – could you consider asynchronous services support from a REST perspective and suggest a specification?

CONCLUSION: we will support RPC, Document-style and REST services, but REST services cannot (right now) be asynchronous.

Localization issues

Support for different languages

Registry contents should be UTF-8
– Registry code needs to check this, and if it isn’t UTF-8 then either convert it, or reject it, or save the encoding. DECISION: Registry converts all incoming XML into UTF-8.

From Services
– We send data in whatever encoding we want, and clients need to be clevererer… or parser (SAX/LibXML) already knows how to deal wtih these things. We need to pay more attention to this… that was the decision we made… to pay more attention.

Languages: if the xml-lang attribute is defined then it should be maintained and saved in the database and returned when the service description is reconstructed e.g. for a findService. need to capture the language for object, namespace, service, service instances, and secondary parameters.

How will jMoby evolve?

The vote was for Mark to start working on jMoby… bad idea!

What is missing?
– asynchronous services
– Martin will put it into jMoby core. Eddie was very forlorn. Martin assured him that he is only going to repackage Eddie’s code but that Eddie’s code really was good! Using existing libraries is not a good idea right now because they are not up-to-date v.v. the specification.
– how do we handle BIIIG data?

1: Should we pass references to data?
2: Taverna’s upload server, ten pass references – a ticket is given to a service provider to grab the data from a URL.
3: iterator pattern in the Moby API
4: or we should use Web Services protocol to stream data.

v.v. possibility #1
Martin was right, Mark was wrong. The reference to data should be an attribute at the moby:Simple/moby:Collection level, not at the moby:mobyContent level. Should we do this using WSRF so that we can tell the service provider to destroy it when we’ve retrieved the data reference? We think INB should do this, since they’re the experts on WSRF.

Other possibilities will be discussed tomorrow

Do all contained objects have to be there?

Paul and Mark say YES!
Martin and Ivan say NO!
Eddie plays devils advocate – agreeing with Martin but arguing against him. Martin misunderstood and assumed that Eddie was saying something that made sense… he wasn’t 😉

Martin’s solution was even WORSE than bad – that we could pass a novel object type called “NULL” – and we all laughed at him… and he laughed at himself.

The conclusion: Contained objects DO NOT need to be there. The semantics are that if the object is there, and is blank, then the data is known to be blank. If the object is NOT there, this indicates that the service provider does not know what the content should be. So “blank” has meaning, absence also has meaning.

This raises another issue – should we have some way of specifying that an object MUST be there – i.e. is a required field? This would be a change in the registry. The question is, does this “mandatory” flag belong in the object registration or in the service registration, where a service provider says “don’t give me this object unless you are going to give me this property”. We decided that it belongs in the service description, and it should be in the LSID metadata, but NOT in the registry.

Object Templates – request from INB

Q1 is it possible to register a different object type for an existing article inherited by ISA assuming that it is a subclass of the existing type? MAYBE

Q2 is it possible to register a different object type for an existing article inherited by ISA assuming that it is NOT a subclass of the existing type? DEFINITIVE NO!!!

Q3 is it possible to simply send a different object type for an existing article inherited by ISA assuming that it is a child type? YES

A3: Quorum of the RDF committee is present so it is decided by the deciders that we will allow inheritence of objects contained by HAS and HASA without the need to register a new object.


A hasa B in the registry

is valid, but also

is valid.

A1: now, to the more difficult question: can we create object templates? The use-case is validation – we want to be able to restrict what is contained in an object so that we can validate what is given to us.

We cannot see a way around needing to register a new object for every restriction anyway, so we’re not convinced of the utility of these templates. There is a combinatorial problem, but we need a stronger use-case to prove that it is worth the pain that this change will cause.

Final decision – NO… unless we can find a more convincing use case.

classpath in the CVS

It was decided that the file .classpath.template will be committed to the CVS, and individual developers will have to rename it to .classpath themselves. Then changes to the classpath will not be committed back to the CVS