The current implementation of the FE thrift server waits
indefinitely to open the new session, if the maximum number of
FE service threads specified by --fe_service_threads has been
allocated.
This patch introduces a startup flag to control how the server
should treat new connection requests if we have run out of the
configured number of server threads.
If --accepted_client_cnxn_timeout > 0, new connection requests are
rejected by the server if we can't get a server thread within
the specified timeout.
We set the default timeout to be 5 minutes. The old behavior
can be restored by setting --accepted_client_cnxn_timeout=0,
i.e., no timeout. The timeout applies only to client facing thrift
servers, i.e., HS2 and Beeswax servers.
Testing:
Added a new custom cluster test suite to exercise the
new code.
Ran core and exhaustive tests.
Change-Id: Idb345c1d84cc2f691f54ded467f253e758f87e64
Reviewed-on: http://gerrit.cloudera.org:8080/12579
Reviewed-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com>
Tested-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com>
