attempt to cut api workers in half

One of the key reasons for the large number of API_WORKERS was that
mysql would block API workers, so would start rejecting work. Now with
the python mysql driver we should be eventlet aware, and life should
be good.

Let's see if this works.

Change-Id: Iaf8730a4dcdc30ef390795bfb5fb73ec3cd665fe
diff --git a/lib/nova b/lib/nova
index ab5a76e..db79678 100644
--- a/lib/nova
+++ b/lib/nova
@@ -607,6 +607,8 @@
     iniset $NOVA_CONF DEFAULT osapi_compute_workers "$API_WORKERS"
     iniset $NOVA_CONF DEFAULT ec2_workers "$API_WORKERS"
     iniset $NOVA_CONF DEFAULT metadata_workers "$API_WORKERS"
+    # don't let the conductor get out of control now that we're using a pure python db driver
+    iniset $NOVA_CONF conductor workers "$API_WORKERS"
 
     iniset $NOVA_CONF cinder os_region_name "$REGION_NAME"
 
diff --git a/stackrc b/stackrc
index 2641be6..9e05d82 100644
--- a/stackrc
+++ b/stackrc
@@ -631,7 +631,7 @@
 # the memory used where there are a large number of CPUs present
 # (the default number of workers for many services is the number of CPUs)
 # Also sets the minimum number of workers to 2.
-API_WORKERS=${API_WORKERS:=$(( ($(nproc)/2)<2 ? 2 : ($(nproc)/2) ))}
+API_WORKERS=${API_WORKERS:=$(( ($(nproc)/4)<2 ? 2 : ($(nproc)/4) ))}
 
 # Service startup timeout
 SERVICE_TIMEOUT=${SERVICE_TIMEOUT:-60}