Of course there is nothing saying a new discussion changes all that and we choose to try and support rolling upgrades over major releases until we decide to have a *break* release or something. I'm just saying what is.
Rolling upgrades forever puts us in a tight spot like Lucene was in with API and runtime behavior previously. At the same time, we probably will often go a couple release without doing things that require major breaks. - Mark On Tue, Feb 23, 2016 at 8:20 PM Mark Miller <[email protected]> wrote: > I'm not confident it won't work. I'm confident that it's not tested and > any dev in any change someone is not paying attention to can make it not > work. So to say it will work or to even count on it working is silly. The > are tons of behavior changes beyond what's in ZK that could mess with > rolling upgrades. We find issues doing non rolling upgrades on *point* > releases in my experience. > > The only way you will ever know is to test it out when the release > happens, and even then, not every issue is easily caught by a simple test. > Commands can come in during the rolling upgrade, certain features can be > broken, etc, etc. > > I would like to support rolling updates on point releases, that's def a > goal, even that is still a bit of prayer as it's not properly tested and it > can depend on what version you coming from and going to. > > - Mark > > > On Tue, Feb 23, 2016 at 1:54 PM Shai Erera <[email protected]> wrote: > >> Mark, I understand that we currently don't have any other promises :). I >> asked in case you happen to know that "oh yeah, in 6.0 we've changed ZK to >> refer to /solr_collections instead of /collections" (I wish it would be >> *that* trivial :)). >> >> If you don't have a list that's fine. You just sounded really confident >> that 5.x -> 6.0 won't work, so I hoped you also can tell why. >> >> I think we should try to be back-compat here, i.e. that a 6.0 (or 7.0) >> can read a 5.0 (or 6.0) Solr. If ZK is our "format", then we should treat >> it as a thing we want to support. That's just my opinion though. >> >> Shai >> >> On Tue, Feb 23, 2016 at 8:46 PM Anshum Gupta <[email protected]> >> wrote: >> >>> For that, we provide an index upgrade tool with 6.0, like we did in 5.0. >>> >>> On Tue, Feb 23, 2016 at 10:41 AM, Mike Drob <[email protected]> wrote: >>> >>>> A 5.x Solr could have indices that are still in a 4.x format, right? >>>> That would be one point where it's not "fully back compatible." >>>> >>>> On Tue, Feb 23, 2016 at 12:27 PM, Shai Erera <[email protected]> wrote: >>>> >>>>> Wait, what do you mean by Lucene not supporting back-compat? Lucene >>>>> 6.0 will be able to read Lucene 5.0 indexes. The only thing that we don't >>>>> guarantee support for is API, which isn't the case here. >>>>> >>>>> So what's in 6.0 that can't read a 5.x Solr. It can't be the index >>>>> format since that's supported by Lucene. Is it the ZK format? If so, >>>>> should >>>>> we try to "version" it so that a 6.0 code can read a 5.x version? Is it >>>>> something else / additionally? >>>>> >>>>> Shai >>>>> >>>>> On Tue, Feb 23, 2016 at 7:06 PM Mark Miller <[email protected]> >>>>> wrote: >>>>> >>>>>> Yes, we are allowed wide berth to break backcompat across major >>>>>> versions and we cannot support rolling updates for the same reason Lucene >>>>>> stopped trying to do full back compat across major versions. Without, we >>>>>> can't properly innovate in the code or fix past mistakes and would also >>>>>> burn lots of cycles we don't have on crazy, "sophisticated" back compat >>>>>> layers. >>>>>> >>>>>> We don't even really support rolling updates between major versions. >>>>>> We make a simple best effort. Until we have tests, it's going to be a >>>>>> shaky >>>>>> affair. There is a JIRA open now working on some testing I believe. >>>>>> >>>>>> - Mark >>>>>> >>>>>> On Tue, Feb 23, 2016 at 11:29 AM Shai Erera <[email protected]> wrote: >>>>>> >>>>>>> Hi >>>>>>> >>>>>>> I read in few emails/issue comments that rolling upgrades from 5.x >>>>>>> to 6.0 isn't supported. Is it really the case? Does it mean that anyone >>>>>>> who >>>>>>> has a 5.x Solr cluster *must* incur down time when upgrading to 6.0? >>>>>>> >>>>>>> If this is really the case, can someone list the known >>>>>>> issues/reasons for that?Can we do something about it, e.g. in a >>>>>>> subsequent >>>>>>> 5.6 release that will allow rolling upgrades (like the 5.4.1 fix that >>>>>>> allowed rolling upgrades from pre-5.4 to 5.4)? >>>>>>> >>>>>>> I feel it's odd (and may not be taken well) if we force users to >>>>>>> take down their entire cluster if they want to upgrade to 6.0. >>>>>>> Definitely >>>>>>> feels like it will also slow down 6.0 adoption. >>>>>>> >>>>>>> And if nothing can be done, what's the recommended way then to >>>>>>> upgrade to 6.0? >>>>>>> >>>>>>> Shai >>>>>>> >>>>>> -- >>>>>> - Mark >>>>>> about.me/markrmiller >>>>>> >>>>> >>>> >>> >>> >>> -- >>> Anshum Gupta >>> >> -- > - Mark > about.me/markrmiller > -- - Mark about.me/markrmiller
