paul-rogers commented on a change in pull request #2000: DRILL-7607: support dynamic credit based flow control URL: https://github.com/apache/drill/pull/2000#discussion_r385997180
########## File path: protocol/src/main/protobuf/BitData.proto ########## @@ -50,3 +52,7 @@ message RuntimeFilterBDef{ optional int32 hj_op_id = 7; // the operator id of the HashJoin which generates this RuntimeFilter optional int64 rf_identifier = 8; // the runtime filter identifier } + +message AckWithCredit{ Review comment: Although it is not a good design, Drill clients use the same RPC protocol as Drillbits. We recently with Drill 1.17 had an issue where we changed a protobuf in a way that broke the C++ ODBC driver. At present the project is thinly staffed; we lack C++ expertise and it may take a while to get the ODBC driver updated. Further, as Drill is rolled out in organizations, we cannot expect clients to update in sync with each server release. Also, we may have people using a single client to speak to Drillbits of different versions. All of is a preface to asking: is this a safe change? Is it backward compatible? If not, is there a way to use optional fields in an existing message to accomplish the same thing without breaking backward compatibility? I understand hacking the current protocol is not elegant. But, is it possible to ensure compatibility? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services