Hi Vishal - That's right - design, not implementation!
I'd encourage you to share a design document once you feel you understand exactly what's required. This is probably going to be complex patch and reviewers will need a study guide :) cheers, Henry On 3 May 2010 10:26, Vishal Kher <vishalm...@gmail.com> wrote: > Hi Henry, > > Thanks for the info. I will spend some more time to understand the issues > before starting with the implementation. I will let you know if I have any > questions (which I am sure I will). > > Just to clarify, "by solved issue" you mean from design perspective and not > from implementation right? > Regards, > -Vishal > On Mon, May 3, 2010 at 1:16 PM, Henry Robinson <he...@cloudera.com> wrote: > > > Hi Vishal - > > > > Great that you're interested in contributing! This would be a really neat > > feature to get into ZK. > > > > The documentation that exists is essentially all on the JIRA. I had a > patch > > that 'worked' but was nowhere near commit-ready. I'm trying to dig it up, > > but it appears it may have gone to the great bit-bucket in the sky. Trunk > > has moved sufficiently that a new patch would be required anyhow. > > > > There were two main difficulties with this issue. The first is changing > the > > voting protocol to cope with changes in views. Since proposals are > > pipelined, the leader needs to keep track of what the view was that > should > > vote for a proposal. IIRC, the other subtlety is making sure that when a > > view change is proposed, a quorum of votes is received from both the > > outgoing view and the incoming one. Otherwise it's possible to transition > > to > > a 'dead' view in which no progress can be made. > > > > The second is to figure out the metadata management - how do we 'find' > > ZooKeeper servers if the ensemble may have moved onto a completely > separate > > set of machines? That is, if the original ensemble was on A, B, C and the > > current ensemble is D, E, F - where do we look to find where the ensemble > > is > > located? > > > > The first is a solved issue, the second is more a matter of taste than > > designing distributed protocols. > > > > Really happy to help with this issue - I'd love to see it get > resurrected. > > > > cheers, > > Henry > > > > On 3 May 2010 07:25, Vishal K <vishalm...@gmail.com> wrote: > > > > > Hi Henry, > > > > > > I just commented on the Jira. I would be happy to contribute. > > > Please advise on the current status and next steps. Thanks. > > > > > > Regards, > > > -Vishal > > > > > > > > > > > -- > > Henry Robinson > > Software Engineer > > Cloudera > > 415-994-6679 > > > -- Henry Robinson Software Engineer Cloudera 415-994-6679
