0MQ: The Intelligent Transport Layer

[Rob Seaman]

Questions, we got questions...

On Dec 20, 2011, at 4:51 PM, Matthew Graham wrote:

> - Is there conceptually anything wrong with the existing infrastructure?
> - Is it just a case that the current tools are not good enough and no-one has been bothered enough to dedicate some time to sorting this out?
> - What exactly are our use cases for event transport?

On Dec 20, 2011, at 6:14 PM, John Swinbank wrote:

> Naive question: what existing Jabber infrastructure is there?
> ...my understanding was that VOEventNet is defunct [?]

(implied question mark at the end, there)

VOEventNet is neither "existing" nor "defunct".  Infrastructure has an evolutionary lifecycle.  The first VOEvent transport prototype was a variation of vanilla TCP.  The second (at the 2005 NVO summer school) was something called Elvin (an orphan technology since around 2007).  In addition to Jabber there was a prototype using Java messaging.  RSS as well as the web.  Others like Roy lists.

VOEvent appears to be doing pretty well as a brand name as well as a technology.  One might therefore expect VOEventNet to survive as a generic notion of the deployed infrastructure as it evolves and ramifies, independently of grants and projects.  At any given epoch we will have one or more deployed functional systems and/or prototypes.  A key requirement will be interoperability between systems at a single epoch and between one epoch and the next.  The network will have bridges in other words.

Two of the current VOEvent-compatible transport systems are SkyAlert and GCN.  These are responsive to different sets of requirements and overlapping but differing stakeholders.  We know that future transport must scale upwards dramatically.  Personally I suspect none of the current transport layers will be up to that scalability.  More to the point we will need dedicated and deployed infrastructure - permanently funded and maintained servers and network links and operations staff.  On the other hand I suspect that we already know the future players out of whom this enhanced commitment will grow.  Which is to say that the people issues are at least as challenging as the technology issues.

Rob