Be down initially

Before ths change containers used to come up in the initial VIP state of up
("in rotation") before having any information about downstream cløusters.
This is problematic if the node determines that it should be
down when learning the state of downstream clusters, especially
when it is determining that it should be down due to failing to complete
pings timely due to initialization load.

This changes to starting in the down state. Crucially, this requires
tracking the current state of clusters in a separate component
such that the state survives reconfiguration and we avoid setting the
state down briefly on each reconfiguration.

In addition to the case where there are downstream clusters deciding
the VIP state oif a container, there are two others:
- There are no such clusters. In this case the VIP state will be up by default.
- Some other component is explicitly deciding the VIP state. This commit makes
  that case clearer.

1 files changed, 11 insertions, 2 deletions

diff --git a/container-core/src/test/java/com/yahoo/container/handler/VipStatusTestCase.java b/container-core/src/test/java/com/yahoo/container/handler/VipStatusTestCase.java
index 725f8256ba3..e54f968f41d 100644
--- a/container-core/src/test/java/com/yahoo/container/handler/VipStatusTestCase.java
+++ b/container-core/src/test/java/com/yahoo/container/handler/VipStatusTestCase.java
@@ -13,13 +13,22 @@ import org.junit.Test;
 public class VipStatusTestCase {
 
     @Test
-    public final void testSmoke() {
+    public void testVipStatusWorksWithClusters() {
+        ClustersStatus clustersStatus = new ClustersStatus();
+        clustersStatus.setContainerHasClusters(true);
+        VipStatus v = new VipStatus(clustersStatus);
+
         Object cluster1 = new Object();
         Object cluster2 = new Object();
         Object cluster3 = new Object();
-        VipStatus v = new VipStatus();
+
         // initial state
+        assertFalse(v.isInRotation());
+
+        // one cluster becomes up
+        v.addToRotation(cluster1);
         assertTrue(v.isInRotation());
+
         // all clusters down
         v.removeFromRotation(cluster1);
         v.removeFromRotation(cluster2);