Hi Kuldeep, I just want to provide you some background info about our documentation. The reason to upgrade to 3.4.6 first is to avoid the following error:
> 2013-01-30 11:32:10,663 [myid:2] - WARN [localhost/127.0.0.1:2784 :QuorumCnxManager@349] - Invalid server id: -65536 This error comes because of the protocol changes between ZooKeeper server nodes during connection initiation for leader election. In ZooKeeper 3.5 a protocol version was introduced (see ZOOKEEPER-107) and since that time the fist long value sent in the initial message is not the server ID but the protocol version (-65536). In ZooKeeper 3.4.6 we made the old 3.4 ZooKeepers backward compatible, so they are able to parse both the old and the new protocol format (see ZOOKEEPER-1633). This issue happens only when you need to use old (3.4.0 - 3.4.5) and new (3.5.0+) ZooKeeper servers together in the same cluster. During a rolling upgrade, this is usually the case to have old and new ZooKeepers present together. The fact that you haven't seen any issues might be caused by the order of the servers. In ZooKeeper the connection initiation between the servers during the leader election follows a specific rule. As far as I remember always the server with the larger ID 'wins the challenge', so it is possible, that the old server didn't need to parse any initial message (if it had the largest ID) and this is why you haven't seen the issue. Also having 2 nodes up from the 3 nodes cluster still makes the cluster work (so you should also check if all the servers are part of the quorum). I agree with Enrico and Norbert, the safest and most stable way is upgrade first to 3.4.latest, then go to 3.5.latest. Still, if you don't see that you would hit this specific issue (e.g. no "Invalid server id" in the log files), and all the three servers can handle traffic, then maybe you don't need to upgrade first to 3.4.latest, it is your decision. Definitely you should test it first, as suggested by the others. Kind regards, Mate On Tue, Mar 24, 2020 at 12:29 PM Norbert Kalmar <nkal...@cloudera.com.invalid> wrote: > Hi, > > That guide is to upgrade to 3.5.0, which was an alpha version. A lot has > changed for the first stable release of 3.5.5 and then a few more, even > rolling upgrade issues have been fixed for 3.5.6. > This is a more up-to-date guide: > https://cwiki.apache.org/confluence/display/ZOOKEEPER/Upgrade+FAQ > > If you have done your testing (with prod snapshot!), then you can skip 3.4 > latest upgrade, but keep in mind we do our recommendations for a reason. > There were issues reported and/or found during testing. Some are fixed with > 3.5.6, some only happens if certain conditions stand (IOException: No > snapshot found - mentioned in the guide, fixed in 3.5.6). > > So it is up to you, I would still recommend to do an 3.4 upgrade first, if > it's feasible. > > Regards, > Norbert > > On Tue, Mar 24, 2020 at 11:45 AM kuldeep singh <kuldeep.sing...@gmail.com> > wrote: > > > Hi, > > > > Current Zookeeper version :- 3.4.5 > > Upgraded version :- 3.5.6 > > > > We are not going with 3.5.7. Our final decision is zookeeper version is > > 3.5.6 > > as per your reply first we need to move latest version of 3.4.x, like > below > > > > 3.4.5 -> 3.4.14 -> 3.5.6 (Correct me if I am wrong here) > > > > But if We are not facing any problem that i have shared you that we have > > set up of 3 node cluster where 2 node are on 3.5.6 version and 1 node on > > 3.4.5, Everything is running fine and didn't get any issue, So what other > > problem we can face if we directly move to 3.5.6 > > > > Thanks, > > --------------------- > > Kuldeep Singh Budania > > Software Architect > > > > > > On Tue, Mar 24, 2020 at 3:58 PM Enrico Olivelli <eolive...@gmail.com> > > wrote: > > > > > Hi > > > You have to upgrade to latest 3.4.x Zookeeper then you will upgrade to > > > 3.5.7. > > > All should run well without issues > > > > > > > > > Enrico > > > > > > Il Mar 24 Mar 2020, 10:18 kuldeep singh <kuldeep.sing...@gmail.com> ha > > > scritto: > > > > > > > Hi Team, > > > > > > > > We are upgrading zookeeper from 3.4.5 to 3.5.6. I have set up 3 node > > > > cluster where 2 node are on 3.5.6 version and 1 node on 3.4.5. > > > > > > > > Everything is running fine and didn't get any issue on my system. > > > > > > > > but I found something on apache site that first we need to upgrade > on > > > > 3.4.6 than we can upgrade to 3.5.6. So is it mandatory to go on > 3.4.6 > > > > first. > > > > > > > > *Upgrading to 3.5.0* > > > > > > > > Upgrading a running ZooKeeper ensemble to 3.5.0 should be done only > > after > > > > upgrading your ensemble to the 3.4.6 release. Note that this is only > > > > necessary for rolling upgrades (if you're fine with shutting down the > > > > system completely, you don't have to go through 3.4.6). If you > attempt > > a > > > > rolling upgrade without going through 3.4.6 (for example from 3.4.5), > > you > > > > may get the following error: > > > > > > > > 2013-01-30 11:32:10,663 [myid:2] - INFO [localhost/127.0.0.1:2784 > > > > :QuorumCnxManager$Listener@498] - Received connection request / > > > > 127.0.0.1:60876 > > > > > > > > 2013-01-30 11:32:10,663 [myid:2] - WARN [localhost/127.0.0.1:2784 > > > > :QuorumCnxManager@349] - Invalid server id: -65536 > > > > > > > > During a rolling upgrade, each server is taken down in turn and > > rebooted > > > > with the new 3.5.0 binaries. Before starting the server with 3.5.0 > > > > binaries, we highly recommend updating the configuration file so that > > all > > > > server statements "server.x=..." contain client ports (see the > section > > > > Specifying > > > > the client port). As explained earlier you may leave the > configuration > > > in a > > > > single file, as well as leave the clientPort/clientPortAddress > > statements > > > > (although if you specify client ports in the new format, these > > statements > > > > are now redundant). > > > > > > > > Could you please let me know about this case. Appreciate if respond > > soon. > > > > > > > > Thanks, > > > > --------------------- > > > > Kuldeep Singh Budania > > > > > > > > > >
