So, is mxzid enough? Do we check version too? Is compared the data even necessary?
-JZ > On Mar 12, 2017, at 2:14 PM, Scott Blum <[email protected]> wrote: > > Oh, this is related to CURATOR-391 https://github.com/apache/curator/pull/202 > <https://github.com/apache/curator/pull/202> > > You wrote: > Using only Stat version to note node change (for UPDATE event) is not enough. > In a split brain if a node delete plus a recreate is missed, the Stat version > can appear to be the same. > > I never considered this corner case! So yeah, I agree that mxzid would be > more reliable. > > > On Sun, Mar 12, 2017 at 5:09 PM, Scott Blum <[email protected] > <mailto:[email protected]>> wrote: > I think "version" and "mzxid" should be equally reliable for determining that > the contents changed. Whenever a change happens the version gets incremented > while the mzxid gets set to the associated zk transaction id. So I don't see > a problem with ifVersion == data.getStat().getVersion() but I haven't looked > through all the PathChildrenCache code in a while, was there something else > you were referring to going on in there? > > On Sun, Mar 12, 2017 at 1:23 PM, Jordan Zimmerman <[email protected] > <mailto:[email protected]>> wrote: > I'm working on CURATOR-391 and notice that TreeCache uses Mzxid to determine > if a ZNode has changed. PathChildrenCache uses a less reliable method. I > _think_ that Mzxid is enough. Does everyone else agree? > > -Jordan > >
