Set default TTL for memcache item expiration

Fixes: PROD-26960

Change-Id: I8880277c1c0fa3b6cbea1c26fcdf09d13b92a5e8
diff --git a/tests/pillar/compute_cluster.sls b/tests/pillar/compute_cluster.sls
index 7c79c8a..d1a4e82 100644
--- a/tests/pillar/compute_cluster.sls
+++ b/tests/pillar/compute_cluster.sls
@@ -67,6 +67,10 @@
       password: metadata
     cache:
       engine: memcached
+      expiration_time: 600
+      backend_argument:
+        memcached_expire_time:
+          value: 660
       members:
       - host: 127.0.0.1
         port: 11211