Yes, I omitted the session ID intentionally due to confusion of "what
the heck is that random string". I thought I had mentioned that there is
a uniqueness string on there to identify instances of servers on the
same host and port, but maybe I dropped that out in the end.
Ultimately, it's not really relevant for the assignment discussion,
assignment just cares about a unique instance of a server. I'll see if I
can maybe clarify that.
Thanks for taking the time to read and send back some feedback!
Keith Turner wrote:
i noticed the document uses<server>:<port> to identify tablet servers in
some places. Something more specific is used in the code
:<server>:<port>:<zk session id>. This last dimension allows the master
to distinguish between two different instances of a tserver running at the
same host and port at different times.
On Wed, Aug 12, 2015 at 12:39 PM, Josh Elser<[email protected]> wrote:
I had some HBase friends ask me for a design document on how Tablet
assignment in Accumulo works. Their assignment logic continues to be a pain
point and there's been a lot of confusion about wanting to use FATE for
assignments (even moreso when I would tell people: no, that's unnecessary).
Since we didn't have a good reference document (I'm guessing because it
was designed prior to the initial import of code), I took the time to write
one up based on my understanding of the code and some pointers from Eric.
Think this deserves a place in our documentation somewhere? Seems like
it's a good reference sheet to have lying around, but I'm not sure where
best it'd be stored.
Huge thanks to Eric for his pointers and editing.
http://people.apache.org/~elserj/AccumuloTabletAssignment.pdf
- Josh
