Don't try to copy files if just one config server

1 files changed, 1 insertions, 0 deletions

diff --git a/config/src/main/java/com/yahoo/vespa/config/JRTConnectionPool.java b/config/src/main/java/com/yahoo/vespa/config/JRTConnectionPool.java
index 048c82b1bde..14385cbc90e 100644
--- a/config/src/main/java/com/yahoo/vespa/config/JRTConnectionPool.java
+++ b/config/src/main/java/com/yahoo/vespa/config/JRTConnectionPool.java
@@ -41,6 +41,7 @@ public class JRTConnectionPool implements ConnectionPool {
     }
 
     public JRTConnectionPool(ConfigSourceSet sourceSet, Supervisor supervisor) {
+        if (sourceSet.getSources().isEmpty()) throw new IllegalArgumentException("sourceSet cannot be empty");
         this.supervisor = supervisor;
         this.poolName = supervisor.transport().getName();
         addSources(sourceSet);