Wire dedicated-CCC from previous to copied sessions, and add some doc

4 files changed, 14 insertions, 0 deletions

diff --git a/configserver/src/main/java/com/yahoo/vespa/config/server/application/ApplicationCuratorDatabase.java b/configserver/src/main/java/com/yahoo/vespa/config/server/application/ApplicationCuratorDatabase.java
index 8b3bcb3e25b..9529e25b37b 100644
--- a/configserver/src/main/java/com/yahoo/vespa/config/server/application/ApplicationCuratorDatabase.java
+++ b/configserver/src/main/java/com/yahoo/vespa/config/server/application/ApplicationCuratorDatabase.java
@@ -159,6 +159,7 @@ public class ApplicationCuratorDatabase {
         return applicationsPath.append(id.serializedForm());
     }
 
+    // Used to determine whether future preparations of this application should use a dedicated CCC.
     private Path dedicatedClusterControllerClusterPath(ApplicationId id) {
         return applicationPath(id).append("dedicatedClusterControllerCluster");
     }
diff --git a/configserver/src/main/java/com/yahoo/vespa/config/server/session/Session.java b/configserver/src/main/java/com/yahoo/vespa/config/server/session/Session.java
index 9b74eac5631..275d293e227 100644
--- a/configserver/src/main/java/com/yahoo/vespa/config/server/session/Session.java
+++ b/configserver/src/main/java/com/yahoo/vespa/config/server/session/Session.java
@@ -158,6 +158,14 @@ public abstract class Session implements Comparable<Session>  {
         return sessionZooKeeperClient.getAllocatedHosts();
     }
 
+    public void setDedicatedClusterControllerCluster() {
+        sessionZooKeeperClient.writeDedicatedClusterControllerCluster();
+    }
+
+    public boolean getDedicatedClusterControllerCluster() {
+        return sessionZooKeeperClient.readDedicatedClusterControllerCluster();
+    }
+
     public Transaction createDeactivateTransaction() {
         return createSetStatusTransaction(Status.DEACTIVATE);
     }
diff --git a/configserver/src/main/java/com/yahoo/vespa/config/server/session/SessionRepository.java b/configserver/src/main/java/com/yahoo/vespa/config/server/session/SessionRepository.java
index 76fd57a51cf..9bfa1e59414 100644
--- a/configserver/src/main/java/com/yahoo/vespa/config/server/session/SessionRepository.java
+++ b/configserver/src/main/java/com/yahoo/vespa/config/server/session/SessionRepository.java
@@ -255,6 +255,8 @@ public class SessionRepository {
         session.setVespaVersion(existingSession.getVespaVersion());
         session.setDockerImageRepository(existingSession.getDockerImageRepository());
         session.setAthenzDomain(existingSession.getAthenzDomain());
+        if (existingSession.getDedicatedClusterControllerCluster())
+            session.setDedicatedClusterControllerCluster();
         return session;
     }
 
diff --git a/configserver/src/main/java/com/yahoo/vespa/config/server/session/SessionZooKeeperClient.java b/configserver/src/main/java/com/yahoo/vespa/config/server/session/SessionZooKeeperClient.java
index aaa3d0b2c35..197964c2677 100644
--- a/configserver/src/main/java/com/yahoo/vespa/config/server/session/SessionZooKeeperClient.java
+++ b/configserver/src/main/java/com/yahoo/vespa/config/server/session/SessionZooKeeperClient.java
@@ -52,6 +52,9 @@ public class SessionZooKeeperClient {
     private static final String DOCKER_IMAGE_REPOSITORY_PATH = "dockerImageRepository";
     private static final String ATHENZ_DOMAIN = "athenzDomain";
     private static final String QUOTA_PATH = "quota";
+
+    // Whether the deployment of this particular session should use a dedicated CCC.
+    // The one in ApplicationCuratorDatabase signals what all future preparations should use, i.e., here.
     private static final String DEDICATED_CLUSTER_CONTROLLER_CLUSTER_PATH = "dedicatedClusterControllerCluster";
     private final Curator curator;
     private final ConfigCurator configCurator;