[ci] Decrease the concurrent workers for Yugabyte' with -enable_scd_hash_lock flag test

build/dev/probe_locally.sh

@@ -59,6 +59,13 @@ if [[ "${CORE_SERVICE_EXTRA_FLAGS:-}" == *"-enable_time_based_notification_index
 	PROBER_EXTRA_ARGS+=(--scd-time-based-notification-index true)
 fi
 
+# Following the extension of performance testing in https://github.com/interuss/dss/pull/1618
+# The Yugabyte test with the -enable_scd_hash_lock flag faces intermittent load-sensitive test failures, so we reduce the
+# concurrent worker count to 1 for that specific configuration.
+if [[ "${COMPOSE_PROFILES:-}" == *"yugabyte"* && "${CORE_SERVICE_EXTRA_FLAGS:-}" == *"-enable_scd_hash_lock"* ]]; then
+	PROBER_EXTRA_ARGS+=(--heavy_traffic_concurrent_workers 1)
+fi
+
 if ! docker run --rm --link "$OAUTH_CONTAINER":oauth \
 	--link "$CORE_SERVICE_CONTAINER":core-service \
 	--network dss_sandbox-default \

docs/operations/performances.md

@@ -51,6 +51,8 @@ This should be better than global lock, as long as cells used don't collide and
 
 The number of locks (65535) is a compromise between lock contention (the more locks, the less unrelated cells share the same one) and the size of the `scd_locks` table. It is fixed and cannot be changed.
 
+Note that this flag creates intermittent load-sensitive test failures when used with Yugabyte. See PR [#1659](https://github.com/interuss/dss/pull/1659) for more details.
+
 ## The time-based notification index option
 
 !!! danger