PYTHON-3088 Update load balancer tests to support dedicated load balancer port (#866)

Author: juliusgeo

.evergreen/config.yml

@@ -292,6 +292,7 @@ functions:
             DISABLE_TEST_COMMANDS=${DISABLE_TEST_COMMANDS} \
             ORCHESTRATION_FILE=${ORCHESTRATION_FILE} \
             REQUIRE_API_VERSION=${REQUIRE_API_VERSION} \
+            LOAD_BALANCER=${LOAD_BALANCER} \
             bash ${DRIVERS_TOOLS}/.evergreen/run-orchestration.sh
     # run-orchestration generates expansion file with the MONGODB_URI for the cluster
     - command: expansions.update
@@ -457,6 +458,7 @@ functions:
           fi
           if [ -n "${test_loadbalancer}" ]; then
             export TEST_LOADBALANCER=1
+            export LOAD_BALANCER=1
             export SINGLE_MONGOS_LB_URI="${SINGLE_MONGOS_LB_URI}"
             export MULTI_MONGOS_LB_URI="${MULTI_MONGOS_LB_URI}"
           fi
@@ -1712,8 +1714,12 @@ tasks:
       commands:
         - func: "bootstrap mongo-orchestration"
           vars:
+            VERSION: "latest"
             TOPOLOGY: "sharded_cluster"
+            LOAD_BALANCER: true
         - func: "run load-balancer"
+          vars:
+            LOAD_BALANCER: true
         - func: "run tests"
 
     - name: "test-fips-standalone"

pymongo/pool.py

@@ -248,9 +248,6 @@ def _set_keepalive_times(sock):
 # main thread, to avoid the deadlock. See PYTHON-607.
 "foo".encode("idna")
 
-# Remove after PYTHON-2712
-_MOCK_SERVICE_ID = False
-
 
 def _raise_connection_failure(address, error, msg_prefix=None):
     """Convert a socket.error to ConnectionFailure and raise it."""
@@ -633,10 +630,6 @@ def _hello(self, cluster_time, topology_version, heartbeat_frequency):
             auth_ctx = None
 
         doc = self.command("admin", cmd, publish_events=False, exhaust_allowed=awaitable)
-        # PYTHON-2712 will remove this topologyVersion fallback logic.
-        if self.opts.load_balanced and _MOCK_SERVICE_ID:
-            process_id = doc.get("topologyVersion", {}).get("processId")
-            doc.setdefault("serviceId", process_id)
         if not self.opts.load_balanced:
             doc.pop("serviceId", None)
         hello = Hello(doc, awaitable=awaitable)

test/__init__.py

@@ -101,10 +101,6 @@
 SINGLE_MONGOS_LB_URI = os.environ.get("SINGLE_MONGOS_LB_URI")
 MULTI_MONGOS_LB_URI = os.environ.get("MULTI_MONGOS_LB_URI")
 if TEST_LOADBALANCER:
-    # Remove after PYTHON-2712
-    from pymongo import pool
-
-    pool._MOCK_SERVICE_ID = True
     res = parse_uri(SINGLE_MONGOS_LB_URI or "")
     host, port = res["nodelist"][0]
     db_user = res["username"] or db_user