问题
P2p/Grid Computing seem like a promising concepts. JXTA looks like the only all in one framework for it. Is there a reason this field is so sparsely pursued?
回答1:
I have lead the release of JXTA 2.6 and 2.7 - JXTA is not completely abandoned. Some people have posted patches on the 2.6 branch and it could easily be merged with the 2.7 branch.
There are many reasons why people did not carry on participating to JXTA:
Oracle did not follow-up on their duties regarding project governance, which left the project in a limbo state.
Oracle did not follow-up on a request to move the project to Apache.
The code base was old. We cleaned it and implemented unit tests. But in order to move the project to the next level, it would have required a lot of rewriting. Not enough volunteers.
But more fundamentally, the reason few P2P frameworks took off is because P2P is fundamentally complex when you get into details. Most people don't get it until they start putting their hands in the dirt. It is not possible to implement P2P 'in a simple way'.
So nothing to do with all-Java clients, licensing fees or others.
Update (August 2013): You thought JXTA/JXSE was dead? Well someone worked further on it and developed a DZone tutorial (unfortunately, SO does not allow links to Dzone, so Google: JXSE and Equinox Tutorial).
Update (November 2013): A group of people is working on new releases of JXTA. For more information, register on the mailing lists.
回答2:
I think it's for the same reasons that RMI, CORBA, and Jini aren't much in favor: complex and closed.
Simple and open win most of the time.
It might have had something to do with all-Java clients or licensing fees or something else.
It could be competition. MPI is a widely accepted messaging standard for computing. Hadoop is getting a lot of traction.
UPDATE: The answer that was accepted discusses why people may or may not choose to participate in JXTA. I think my answer has more to do with user adoption, which is different. Mine go back to the origins of JXTA, not the details of releases 2.6 and 2.7.
回答3:
If you work with Linux, try this: http://www.p2pns.org/ "P2PNS (Peer-to-Peer Name Service) is a distributed name service using a peer-to-peer network. The current focus of P2PNS is to provide a secure and efficient SIP name resolution for decentralized VoIP ( P2PSIP)." In most cases Name Resolution is enough to build up a P2P-App on top of it.
回答4:
Interestingly what was missing with all the P2P initiatives of the past was a motivation for a peer to stay active. Question always was why would a peer keep running a CPU draining and XML based verbosed protocols. Trust was another factor - how can I trust a peer. As a key member of the team, we introduced security. But security doesn't address trust.
To make it even worse, JXTA introduced the concept of super nodes - defeating the very concept of peer to peer.
However, not everything was that bad. JXTA provided a lots of new concepts. One being Edge Computing with JXME and JXTA sitting together - you can call it to be current day Fog computing where heavy lifting was on the JXTA node and some intelligence on the constrained JXME nodes.
Fast forward, Blockchain addressed gaps with addressing most if not all the questions that any P2P platform could not answer: trust, incentivizing peers, tamper proof and much more.
P2P is still alive :)
来源：https://stackoverflow.com/questions/10333072/why-has-jxta-been-abandoned-any-alternatives-out-there