SET CONCURRENCY=2

Change-Id: I9b09f1b52b127d6a7f71980f95928c885e067edd
diff --git a/tcp_tests/managers/openstack_manager.py b/tcp_tests/managers/openstack_manager.py
index 275ef57..1699be5 100644
--- a/tcp_tests/managers/openstack_manager.py
+++ b/tcp_tests/managers/openstack_manager.py
@@ -120,6 +120,7 @@
             cmd = ("docker run --rm --net=host  "
                    "-e TEMPEST_CONF={0} "
                    "-e SKIP_LIST=mcp_skip.list "
+                   "-e CONCURRENCY=2 "
                    "-e SOURCE_FILE=keystonercv3  "
                    "-e CUSTOM='--pattern {1}' "
                    "-v /root/:/home/rally  "
@@ -131,6 +132,7 @@
                    "-e TEMPEST_CONF={0} "
                    "-e SKIP_LIST=mcp_skip.list "
                    "-e SET=full "
+                   "-e CONCURRENCY=2 "
                    "-e SOURCE_FILE=keystonercv3  "
                    "-v /root/:/home/rally "
                    "-v /var/log/:/home/rally/rally_reports/ "