> The Oozie servers in your Oozie HA setup actually are all active; that is, > they are all processing jobs at the same time -- there is no failover.
I see. So, this is more of an active-active configuration. I got answers for all my questions. Thanks a lot Robert! Your help is greatly appreciated! Regards, Anand On Fri, Feb 21, 2014 at 1:07 AM, Robert Kanter <[email protected]> wrote: > > > > Is there any known data migration tool which can migrate data from derby > > to let's say mysql? > > Migrating the Oozie data out of Derby to another database is somewhat > tricky. You can take a look at this procedure given on the Cloudera > Community forums, but I can't guarantee that it will work and I can't > really help you with it: > > http://community.cloudera.com/t5/Batch-Processing-and-Workflow/Oozie-embedded-derby-to-mysql-what-is-the-best-way-to-go-about/m-p/5627#M195 > I'd recommend that you just start over with a new empty database in > MySQL/Oracle/Postgres. You won't lose any of the actual > workflows/coordinators themselves, just the historical data; and any > currently running or queues up workflows/coordinators will have to be > resubmitted. > > I also have one more question. Since traditionally oozie database is > local, a > > node outage can make the database unavailable. > > Can we have the oozie database on an nfs mount, so that in case of oozie > server > > process outage, the secondary process which will run on another node, can > > access the database using nfs mount as well? > > The Oozie servers in your Oozie HA setup actually are all active; that is, > they are all processing jobs at the same time -- there is no failover. As > such, the database isn't "local"; that only really has meaning for Derby. > When using MySQL/Oracle/Postgres, the database is always "remote" to each > of the Oozie servers; it may even be a good idea to put it on a different > machine from any of the Oozie servers. I'm not an expert on these > databases, but I don't think you can back them with an NFS mount; each of > these databases has their own HA solution that you should look into. So, > there's no need to worry about an Oozie server process outage with a > secondary process on another node; in Oozie HA, all Oozie servers are equal > -- there is no leader. Does this make sense? > > > > On Thu, Feb 20, 2014 at 8:36 AM, Anand Vidwansa <[email protected]> > wrote: > > > Thanks a lot for the prompt reply Robert! > > I do have lot of data in my derby db which I need to migrate now to > either > > of mysql/oracle/postgres. > > Is there any known data migration tool which can migrate data from derby > to > > let's say mysql? > > > > I also have one more question. Since traditionally oozie database is > local, > > a node outage can make the > > database unavailable. > > Can we have the oozie database on an nfs mount, so that in case of oozie > > server process outage, > > the secondary process which will run on another node, can access the > > database using nfs mount as well? > > > > Thanks, > > Anand > > > > > > On Tue, Feb 18, 2014 at 11:36 PM, Robert Kanter <[email protected] > > >wrote: > > > > > Hi, > > > > > > You can run Oozie without an HA database. A non-HA MySQL, Oracle, or > > > Postgres database will work just fine, other than if the database goes > > > down, your Oozie becomes unavailable (i.e. the database is a single > point > > > of failure). > > > > > > The reason you can't use Derby for Oozie HA is because it doesn't > support > > > multiple concurrent connections. In Oozie HA, each Oozie server > connects > > > to the database, so there are multiple connections; Derby doesn't allow > > > that so only one of the Oozie servers would be able to connect. > > > > > > - Robert > > > > > > > > > On Tue, Feb 18, 2014 at 1:16 AM, Anand Vidwansa <[email protected]> > > > wrote: > > > > > > > Hi, > > > > > > > > I wanted to know if there is a way to configure oozie HA support with > > > derby > > > > as database. > > > > I understand oozie HA support expects an HA database. > > > > But, is there a way to use native replication in derby to replicate > > data > > > > between > > > > two hosts and switch to secondary store in case oozie fails over? > > > > > > > > Any help is appreciated! > > > > > > > > Thanks, > > > > Anand > > > > > > > > > >
