Andrew Sherman has uploaded this change for review. ( http://gerrit.cloudera.org:8080/11459
Change subject: IMPALA-589: Add a sql function to return the impalad coordinator hostname for diagnostic purposes. ...................................................................... IMPALA-589: Add a sql function to return the impalad coordinator hostname for diagnostic purposes. In every execution of an Impala query, one of the impalad daemons acts as the coordinator node. In some cases, such as when using a proxy, a user cannot predict which host will act as the coordinator. To aid in diagnosis, we provide a sql function which returns the name of the host on which the coordinator is running. EXTERNAL DESCRIPTION: Add a builtin function called coordinator(), which returns the name of the host which is running the impalad that is acting as the coordinator for the current query. IMPLEMENTATION: All functions are passed a FunctionContext object which is the interface to the rest of the system for a UDF. From the FunctionContext we get the TQueryCtx (query context) which contains a TNetworkAddress for the coordinator. The hostname of the coordinator is copied from the TNetworkAddress. Can the TNetworkAddress for the coordinator be unitialized? In the thrift source the coord_address is marked optional, but my reading of the code says this is always set in a real impalad. To future-proof the code a null StringVal is returned if coord_address is unset. TESTING: - Added a basic unit test for the new function. - Added a unit test which simulates the case when coord_address is unset. - Hand tested in a development deployment. - Ran regression tests and got a clean run. LIMITATIONS: This change only adds the coordinator() function. It does not add the debug_url() function that was mentioned in the comments on the original Jira. Change-Id: I94d6e2664ba659b48df53c5c06f67b502c533e47 --- M be/src/exprs/expr-test.cc M be/src/exprs/utility-functions-ir.cc M be/src/exprs/utility-functions.h M common/function-registry/impala_functions.py M docs/topics/impala_misc_functions.xml 5 files changed, 61 insertions(+), 0 deletions(-) git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/59/11459/1 -- To view, visit http://gerrit.cloudera.org:8080/11459 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: newchange Gerrit-Change-Id: I94d6e2664ba659b48df53c5c06f67b502c533e47 Gerrit-Change-Number: 11459 Gerrit-PatchSet: 1 Gerrit-Owner: Andrew Sherman <asher...@cloudera.com>
