Paxos provides a primitive for distributed programming that somewhat akin to Compare-And-Swap for multi-threading. It's a little difficult to provide specific examples as it's typically just a detail in how you implement higher-level concepts. That said though, a few things come to mind.
For each of the items listed below, the key benefits of using Paxos are consistency and service availability in the presence of node failures. * A Master-Master version of the Clone pattern mentioned in the guide. A pool of peer servers could coordinate updates to a single, shared key-value store. * Distributed Locking. A pool of servers could be used to allocate and free locks for shared resources. * Maintenance of global configuration data. * Leader election. Pretty much anything you might use Zookeeper for can be accomplished with Paxos. In fact, I first started looking into Paxos because I had a few use cases for which setting up a separate Zookeeper installation wasn't going to be practical. There are some definite tradeoffs to be considered when using it but it's a good tool to have on the shelf. Tom On Sat, Mar 23, 2013 at 2:02 AM, Pieter Hintjens <p...@imatix.com> wrote: > Hi Tom, > > Do you have any examples where Paxos would solve problems faced by > developers using 0MQ? > > -Pieter > > On Sat, Mar 23, 2013 at 7:24 AM, Tom Cocagne <tom.coca...@gmail.com> wrote: >> At a meetup just short of a year ago I was asked to post to the list >> about a Paxos over ZeroMQ side project I'd been working on. At the >> time, the implementation was roughly alpha quality and the code wasn't >> particularly clean but it seemed to be fairly well received. For those >> that are still interested, I'm pleased to say that the project is now >> pretty much complete. All of the major functionality is in place, the >> code has been cleaned up, and the documentation is in decent shape. >> >> All of the other open-source Paxos implementations I've found are >> either horribly over-complicated or they inextricably commingle their >> application-specific logic with their handling of the Paxos algorithm. >> While trying to get up to speed on Paxos, I never did find a good, >> clean example of it's implementation and use. For that reason, I made >> a special effort to gear this implementation specifically for clarity >> and ease of understanding. The project is split into two separate >> repositories. One implements the bare Paxos algorithm >> (https://github.com/cocagne/paxos) and the other uses it on top of >> ZeroMQ (https://github.com/cocagne/zpax). Beyond being just generally >> useful libraries, I'm hoping these implementations will serve as >> approachable examples for others interested in the topic. >> >> Tom >> _______________________________________________ >> zeromq-dev mailing list >> zeromq-dev@lists.zeromq.org >> http://lists.zeromq.org/mailman/listinfo/zeromq-dev > _______________________________________________ > zeromq-dev mailing list > zeromq-dev@lists.zeromq.org > http://lists.zeromq.org/mailman/listinfo/zeromq-dev _______________________________________________ zeromq-dev mailing list zeromq-dev@lists.zeromq.org http://lists.zeromq.org/mailman/listinfo/zeromq-dev
