Add envelope around client<->server communication so can pass state along w/
data during interchange
----------------------------------------------------------------------------------------------------
Key: HBASE-2408
URL: https://issues.apache.org/jira/browse/HBASE-2408
Project: Hadoop HBase
Issue Type: Improvement
Reporter: stack
This issue is about adding a dimension along which we can pass metadata on
changes in client-server communications. What i mean by this is that that
while an HTable#get will return a RowResult, we need to also be able to also
convey, messages like "I got the result for this row from a region other than
the one you asked for -- update your cache with this new location".
I can think of two examples where this mechanism could be useful.
1. HBASE-72 "'Normal' operation should not depend on throwing of exceptions
(e.g. NotServingRegionException)". Rather than have the server throw a
NotServingRegionException as we do now as signal to client to go look elsewhere
for the wanted data, we could instead signal the client to look elsewhere by
setting a state in the envelope.
2. If a client asks for a row and meantime the region has split, if the
regionserver queried is hosting the daughter that is carrying the wanted row,
it could save the client hops by passing back the wanted row with a message in
the envelope that client should update its cache removing parent and replacing
with daughter location.
AVRO rpc carries headers? We could stuff our enveloping stuff there? Or,
shudder, if we used AVRO HTTP for RPC, we could do our messages as HTTP headers.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
