Avoid Slobrok in node-admin cluster

When this rolls out, two Slobroks on the node-admin will be removed, and 1
additional Slobrok will be put on one of the proxy nodes if the routing cluster
has 3 or more nodes.

The Orchestrator sees the latest model, i.e. expect 3 Slobroks on the proxy
nodes. Since the 1 additional Slobrok service is down at the start of the
rollout, only that host will be allowed to suspend among the 3. But if that 1
additional Slobrok service comes up quickly, then any of the 3 can suspend. I
think this will just work - no deadlocks or similar.

I couldn't find any test that would covers this code change, but will write
tests if someone can help me with this, if deemed necessary.

1 files changed, 31 insertions, 10 deletions

diff --git a/config-model/src/main/java/com/yahoo/vespa/model/builder/xml/dom/DomAdminV4Builder.java b/config-model/src/main/java/com/yahoo/vespa/model/builder/xml/dom/DomAdminV4Builder.java
index cc9957144f3..44de53991f4 100644
--- a/config-model/src/main/java/com/yahoo/vespa/model/builder/xml/dom/DomAdminV4Builder.java
+++ b/config-model/src/main/java/com/yahoo/vespa/model/builder/xml/dom/DomAdminV4Builder.java
@@ -2,22 +2,23 @@
 package com.yahoo.vespa.model.builder.xml.dom;
 
 import com.yahoo.component.Version;
+import com.yahoo.config.model.ConfigModelContext;
 import com.yahoo.config.model.api.ConfigServerSpec;
+import com.yahoo.config.provision.ApplicationId;
 import com.yahoo.config.provision.ClusterSpec;
 import com.yahoo.vespa.model.HostResource;
 import com.yahoo.vespa.model.HostSystem;
-import com.yahoo.vespa.model.admin.*;
-import com.yahoo.config.model.ConfigModelContext;
 import com.yahoo.vespa.model.admin.Admin;
+import com.yahoo.vespa.model.admin.Logserver;
+import com.yahoo.vespa.model.admin.Slobrok;
 import com.yahoo.vespa.model.container.Container;
 import com.yahoo.vespa.model.container.ContainerModel;
-
 import org.w3c.dom.Element;
 
 import java.util.ArrayList;
 import java.util.Collection;
-import java.util.Collections;
 import java.util.List;
+import java.util.Objects;
 import java.util.Optional;
 import java.util.stream.Collectors;
 
@@ -27,6 +28,7 @@ import java.util.stream.Collectors;
  * @author bratseth
  */
 public class DomAdminV4Builder extends DomAdminBuilderBase {
+    private ApplicationId ZONE_APPLICATION_ID = ApplicationId.from("hosted-vespa", "routing", "default");
 
     private final Collection<ContainerModel> containerModels;
     private final ConfigModelContext context;
@@ -63,7 +65,7 @@ public class DomAdminV4Builder extends DomAdminBuilderBase {
             createSlobroks(admin, allocateHosts(admin.getHostSystem(), "slobroks", nodesSpecification));
         }
         else {
-            createSlobroks(admin, pickContainerHosts(nodesSpecification.count(), 2));
+            createSlobroks(admin, pickContainerHostsForSlobrok(nodesSpecification.count(), 2));
         }
     }
 
@@ -94,17 +96,36 @@ public class DomAdminV4Builder extends DomAdminBuilderBase {
      *        on topology changes, and less nodes may be returned if fewer are available
      * @param minHostsPerContainerCluster the desired number of hosts per cluster
      */
-    private List<HostResource> pickContainerHosts(int count, int minHostsPerContainerCluster) {
+    private List<HostResource> pickContainerHostsForSlobrok(int count, int minHostsPerContainerCluster) {
+        Collection<ContainerModel> containerModelsWithSlobrok = containerModels.stream()
+                .filter(this::shouldHaveSlobrok)
+                .collect(Collectors.toList());
+        int hostsPerCluster = (int) Math.max(
+                minHostsPerContainerCluster,
+                Math.ceil((double) count / containerModelsWithSlobrok.size()));
+
         // Pick from all container clusters to make sure we don't lose all nodes at once if some clusters are removed.
         // This will overshoot the desired size (due to ceil and picking at least one node per cluster).
         List<HostResource> picked = new ArrayList<>();
-        for (ContainerModel containerModel : containerModels)
-            picked.addAll(pickContainerHostsFrom(containerModel,
-                                                 (int) Math.max(minHostsPerContainerCluster,
-                                                                Math.ceil((double) count / containerModels.size()))));
+        for (ContainerModel containerModel : containerModelsWithSlobrok)
+            picked.addAll(pickContainerHostsFrom(containerModel, hostsPerCluster));
         return picked;
     }
 
+    private boolean shouldHaveSlobrok(ContainerModel containerModel) {
+        // Avoid Slobroks on node-admin container cluster, as node-admin is migrating
+        // TODO: Remove this hack once node-admin has migrated out the zone app
+
+        ApplicationId applicationId = context.getDeployState().getProperties().applicationId();
+        if (!applicationId.equals(ZONE_APPLICATION_ID)) {
+            return true;
+        }
+
+        // aka clustername, aka application-model's ClusterId
+        String clustername = containerModel.getCluster().getName();
+        return !Objects.equals(clustername, "node-admin");
+    }
+
     private List<HostResource> pickContainerHostsFrom(ContainerModel model, int count) {
         boolean retired = true;
         List<HostResource> picked = sortedContainerHostsFrom(model, count, !retired);