Hi Ted, Thanks for your contribution and the accurate design of this proposal. I have the following comments on it:
1) What's the need of the explicit support of multiple network interfaces? DNS names can resolve into multiple address and we could easily implement trying the multiple addresses to a single server in a round-robin fashion. Currently it's done by getByName() which always chooses the first one. What are the benefits of your implementation? 2) In terms of releases. The community already agreed on that 3.4 only accepts critical bug and security fixes. We could always start a vote on anything, but personally I doubt that such a significant change in the networking code could ever make it into 3.4. The reason why we're doing this is that 3.5 is just about to be released very soon, therefore we encourage new features and enhancements to be implemented 3.5 onwards. I believe it needs to get into master first. Once we have an insight on how significant the code change is exactly and the impact, we'll be able to talk about backporting it to 3.5. Don't worry about this too much. We don't want to wait another 4 years to release 3.6: with the current pace of patches from contributors (especially Facebook), we'll have another major (3.6) release very soon. Months rather than years. Regards, Andor On Tue, Nov 13, 2018 at 2:25 PM, Alexander Shraer <shra...@gmail.com> wrote: > This seems like a good feature for ZooKeeper to eventually have, but I > don't see why it must make 3.4 and 3.5 while other features are pushed out > to 3.6. > Like any other feature, it would be subject to a vote and isn't a > unilateral decision. > > On Tue, Nov 13, 2018 at 1:59 PM Ted Dunning <ted.dunn...@gmail.com> wrote: > > > I am going to push this feature out sooner rather than later. That isn't > a > > question. I and my team are going to do the work. Others are very welcome > > to help and I am sure that there will be high value in getting reviews > from > > a wide group. > > > > But we are already working on the code. And we will be pushing a version > > into both 3.4 and 3.5. I think that 3.6-ish is a great target for an > > improved configuration syntax. Better configuration is a great goal, but > it > > isn't OK to delay other work. > > > > > > On Tue, Nov 13, 2018 at 3:47 PM Alexander Shraer <shra...@gmail.com> > > wrote: > > > > > I also wanted to get other's views on this. > > > > > > My opinion is that the current server configuration format > > > (server.x=ip:port:port:role;ip:port) has run its course. There are > > multiple > > > proposals for additions/changes to the server configuration, > > > that would be simplified from having a more extensible format, such as > a > > > json blob, as proposed by Brian Nixon here: > > > https://issues.apache.org/jira/browse/ZOOKEEPER-3166 > > > It is true that such an extension hasn't happened yet, however it may > not > > > be a good idea to continue adding individual features to the existing > > > format instead of making this change. > > > > > > For longer than a year, maybe more, I've seen features pushed out to > 3.6 > > to > > > avoid destabilizing the 3.5 release. If we follow the same logic here, > > this > > > would be a 3.6 feature, so compatibility with the old format doesn't > seem > > > very important. > > > > > > What do others think ? > > > > > > > > > Thanks, > > > Alex > > > > > > > > > > > > On Mon, Nov 12, 2018 at 11:47 PM Ted Dunning <ted.dunn...@gmail.com> > > > wrote: > > > > > > > There is a JIRA live for the network resilience feature that I > > mentioned > > > > previously. > > > > > > > > The design document > > > > < > > > > > > > > > https://docs.google.com/document/d/1iGVwxeHp57qogwfdodCh9b32P2_ > kOQaJZ2GDo7j36fI/edit?usp=sharing > > > > > > > > > (also > > > > copied into the JIRA) has essentially converged except for two > points. > > > > > > > > These include: > > > > > > > > 1) Artem Chernatsky has pointed out an opportunity to factor our port > > > sets > > > > in the configuration syntax as well as an interesting interaction > with > > > the > > > > existing behavior where the current servers already listen to the > > > specified > > > > ports on all NICs. This semantics of this interaction between > > > configuration > > > > options need to be specified rigorously, but this doesn't appear to > > > impact > > > > code complexity much, nor introduce any real difficulties. > > > > > > > > 2) Alex Shraer seems to feel that there is a strong interaction > between > > > > this > > > > issue <https://issues.apache.org/jira/browse/ZOOKEEPER-3188> and a > > > > proposed > > > > refactorization of the configuration file syntax (mentioned in a > > comment > > > in > > > > 3166, but apparently doesn't have an independent issue). In > particular, > > > he > > > > seems to think that the syntax refactorization is a blocker for the > > > network > > > > resilience. My own feeling is that there is some interaction, but > there > > > is > > > > no strong ordering between the two issues if the implementors of this > > > issue > > > > are willing to commit to supporting any consensus syntax change that > is > > > > adopted. Essentially, there can be an additional issue filed which is > > > > blocked by both the syntax change issue and 3188 (network resilience) > > to > > > > support any new syntax. The work for 3188 needs to support the old > > syntax > > > > in any case so that we can backport changes to 3.4. > > > > > > > > Other open issues that are affected by configuration syntax change > > > include > > > > 2534 <https://issues.apache.org/jira/browse/ZOOKEEPER-2534>, 2531 > > > > <https://issues.apache.org/jira/browse/ZOOKEEPER-2531>, 195 > > > > <https://issues.apache.org/jira/browse/ZOOKEEPER-195>, and 2225 > > > > <https://issues.apache.org/jira/browse/ZOOKEEPER-2225>. None of > these > > > has > > > > any serious impact other than the fact that configuration needs to be > > > > abstracted as part of any change. Some appear to be quite old and may > > > have > > > > already been solved or made moot. > > > > > > > > My own feeling is that pushing for this issue (3188) to include a > > change > > > to > > > > the configuration syntax as well as the core network resilience > feature > > > > proposed is an unacceptable increase in scope. I have filed a new > > > tracking > > > > issue <https://issues.apache.org/jira/browse/ZOOKEEPER-3189> (3189) > > > > capturing the intended rework after a change in configuration syntax, > > > but I > > > > can't find anywhere that the configuration change is captured in a > > issue > > > to > > > > add the dependency. > > > > > > > > I also see no particular way that configuration syntax change (as > > > desirable > > > > as it might be) blocks this feature. > > > > > > > > I would love to hear other opinions. > > > > > > > > > > > > I, myself, think that the "support resilience under new syntax when > > > > available" approach > > > > > > > > > >
