In addition to the reasons both Andras's mentioned, another reason is that the client doesn't need to know all of the Oozie server addresses. While you can update the Oozie client config on your laptop if it worked that way, once the Oozie Launcher has started, you can't update the Oozie servers it knows about. For example, suppose you had an Oozie launcher that ran for 3 days - you may have added/removed some Oozie servers in that time and now the Oozie Launcher's list of Oozie servers would be out of date.
- Robert On Mon, Nov 4, 2019 at 4:01 AM Andras Piros <[email protected]> wrote: > Another point to add is that there are lots of users accessing Oozie not > via OozieCLI but via direct REST calls. As to my understanding the proxied > client story could work for OozieCLI only. In any case, it could make sense > to implement it that way. > > Regards, > > Andras > > On Mon, Nov 4, 2019 at 12:56 PM Andras Salamon > <[email protected]> wrote: > > > Hi, > > > > HA was added a long time ago, back in 2013. You can find the jira here: > > https://issues.apache.org/jira/browse/OOZIE-615. There is a design docs > > attached to the jira, which could be a good starting point. There is a > > section int it about the Load Balancer: > > > > "A loadbalancer, virtualIP, or DNSroundrobin: This would go in front of > the > > Oozie servers to (a) provide a single entry point for users so they don’t > > have to choose between, or even beaware of, multiple Oozie servers; and > (b) > > for callbacks from the JobTracker when a hadoop job is done (which can > only > > take a single address and simply choosing an arbitrary Oozie server could > > be a problem if that server goes down." > > > > Best, > > Sala > > > > > > On Sat, Nov 2, 2019 at 12:13 AM Poepping, Thomas > <[email protected] > > > > > wrote: > > > > > Hi Oozie development community! > > > > > > I am looking through documentation for the Oozie High Availability > > feature > > > ( > > https://oozie.apache.org/docs/5.1.0/AG_Install.html#High_Availability_HA > > > ) and I am wondering why we need to set up virtual IP or load balancing > > for > > > callbacks from Resource Manager to Oozie? YARN follows a different > > > convention – including a proxied client that round robins between DNS > > names > > > configured in a list. Is there something blocking Oozie from doing the > > > same, or was this decision made because it also provides users with a > > > single endpoint to hit any of the oozie servers running? > > > > > > If there aren’t strong arguments against, I would like to open a JIRA > to > > > implement this. But first, please give me your comments! > > > > > > Thanks, > > > Tom > > > > > >
