Set heap size flags in nomulus start script (#2956)

* Set heap size flags in nomulus start script

* Add comment for flags

jetty/start.sh

@@ -22,12 +22,15 @@ find . -maxdepth 1 -type d -name "console-*" -exec rm -rf {} +
 cd /jetty-base
 echo "Running ${env}"
 PROFILER_ARGS=""
-# # Use the CONTAINER_NAME variable from Kubernetes YAML to set Cloud profiler args, enable it only in frontend and console.
+# Use the CONTAINER_NAME variable from Kubernetes YAML to set Cloud profiler args, enable it only in frontend and console.
 case "${CONTAINER_NAME}" in
   "frontend"|"console")
   PROFILER_ARGS="-agentpath:/opt/cprof/profiler_java_agent.so=-cprof_service=${CONTAINER_NAME},-cprof_enable_heap_sampling=true"
 esac
 java $PROFILER_ARGS \
+    # Allocate bigger than default fraction of available memory to the application, as it's running in a (single-purposed) container.
+    -XX:InitialRAMPercentage=50.0 \
+    -XX:MaxRAMPercentage=50.0 \
     -Dgoogle.registry.environment=${env} \
     -Djava.util.logging.config.file=/logging.properties \
     -jar /usr/local/jetty/start.jar