2 files changed, 7 insertions, 3 deletions
diff --git a/config/src/main/java/com/yahoo/config/subscription/ConfigSubscriber.java b/config/src/main/java/com/yahoo/config/subscription/ConfigSubscriber.java
index 2873855d1c2..3891d710fa3 100644
--- a/config/src/main/java/com/yahoo/config/subscription/ConfigSubscriber.java
+++ b/config/src/main/java/com/yahoo/config/subscription/ConfigSubscriber.java
@@ -319,6 +319,7 @@ public class ConfigSubscriber implements AutoCloseable {
     @Override
     public void close() {
         synchronized (monitor) {
+            if (state == State.CLOSED) return;
             state = State.CLOSED;
         }
         for (ConfigHandle<? extends ConfigInstance> h : subscriptionHandles) {
diff --git a/config/src/main/java/com/yahoo/config/subscription/impl/JRTManagedConnectionPools.java b/config/src/main/java/com/yahoo/config/subscription/impl/JRTManagedConnectionPools.java
index 0a606416827..32d2d962e4d 100644
--- a/config/src/main/java/com/yahoo/config/subscription/impl/JRTManagedConnectionPools.java
+++ b/config/src/main/java/com/yahoo/config/subscription/impl/JRTManagedConnectionPools.java
@@ -29,7 +29,8 @@ public class JRTManagedConnectionPools {
             count = 0;
         }
     }
-    private Map<ConfigSourceSet, CountedPool> pools = new HashMap<>();
+
+    private final Map<ConfigSourceSet, CountedPool> pools = new HashMap<>();
 
     public JRTConfigRequester acquire(ConfigSourceSet sourceSet, TimingValues timingValues) {
         CountedPool countedPool;
@@ -43,12 +44,14 @@ public class JRTManagedConnectionPools {
         }
         return new JRTConfigRequester(sourceSet, countedPool.scheduler, countedPool.pool, timingValues);
     }
+
     public synchronized void release(ConfigSourceSet sourceSet) {
         CountedPool countedPool;
         synchronized (pools) {
             countedPool = pools.get(sourceSet);
-            countedPool.count--;
-            if (countedPool.count > 0) return;
+            if (countedPool != null)
+                countedPool.count--;
+            if (countedPool == null || countedPool.count > 0) return;
             pools.remove(sourceSet);
         }