Default engine workers to the number of CPUs

The engine is single-threaded and thus needs more workers to handle more
concurrent requests on a single machine.

Change-Id: I36117c3876f84a2ff7ba5576444fdbf7716cc69e

1 files changed, 6 insertions, 1 deletions

diff --git a/bin/heat-engine b/bin/heat-engine
index fe83730e2..0fc0bad10 100755
--- a/bin/heat-engine
+++ b/bin/heat-engine
@@ -21,6 +21,7 @@ which then calls into this engine.
 import eventlet
 eventlet.monkey_patch()
 
+import multiprocessing
 import os
 import sys
 
@@ -61,7 +62,11 @@ if __name__ == '__main__':
 
     from heat.engine import service as engine
 
+    num_workers = cfg.CONF.num_engine_workers
+    if num_workers == -1:
+        num_workers = multiprocessing.cpu_count()
+
     srv = engine.EngineService(cfg.CONF.host, rpc_api.ENGINE_TOPIC)
-    launcher = service.launch(srv, workers=cfg.CONF.num_engine_workers)
+    launcher = service.launch(srv, workers=num_workers)
     notify.startup_notify(cfg.CONF.onready)
     launcher.wait()