1 files changed, 37 insertions, 13 deletions
diff --git a/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/configserver/ConfigServerApi.java b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/configserver/ConfigServerApi.java
index 90768facf34..87e2f6db761 100644
--- a/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/configserver/ConfigServerApi.java
+++ b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/configserver/ConfigServerApi.java
@@ -10,41 +10,65 @@ import java.util.Optional;
  * @author freva
  */
 public interface ConfigServerApi extends AutoCloseable {
-    class Params {
-        private Optional<Duration> connectionTimeout;
+
+    /**
+     * The result of sending a request to a config server results in a jackson response or exception.  If a response
+     * is returned, an instance of this interface is conferred to discard the result and try the next config server,
+     * unless it was the last attempt.
+     *
+     * @param <T> the type of the returned jackson response
+     */
+    interface RetryPolicy<T> {
+        boolean tryNextConfigServer(T response);
+    }
+
+    class Params<T> {
+        private Optional<Duration> connectionTimeout = Optional.empty();
+
+        private RetryPolicy<T> retryPolicy = response -> false;
+
+        public Params() {}
 
         /** Set the socket connect and read timeouts. */
-        public Params setConnectionTimeout(Duration connectionTimeout) {
+        public Params<T> setConnectionTimeout(Duration connectionTimeout) {
             this.connectionTimeout = Optional.of(connectionTimeout);
             return this;
         }
 
         public Optional<Duration> getConnectionTimeout() { return connectionTimeout; }
+
+        /** Set the retry policy to use against the config servers. */
+        public Params<T> setRetryPolicy(RetryPolicy<T> retryPolicy) {
+            this.retryPolicy = retryPolicy;
+            return this;
+        }
+
+        public RetryPolicy<T> getRetryPolicy() { return retryPolicy; }
     }
 
-    <T> T get(String path, Class<T> wantedReturnType, Params params);
+    <T> T get(String path, Class<T> wantedReturnType, Params<T> params);
     default <T> T get(String path, Class<T> wantedReturnType) {
-        return get(path, wantedReturnType, null);
+        return get(path, wantedReturnType, new Params<>());
     }
 
-    <T> T post(String path, Object bodyJsonPojo, Class<T> wantedReturnType, Params params);
+    <T> T post(String path, Object bodyJsonPojo, Class<T> wantedReturnType, Params<T> params);
     default <T> T post(String path, Object bodyJsonPojo, Class<T> wantedReturnType) {
-        return post(path, bodyJsonPojo, wantedReturnType, null);
+        return post(path, bodyJsonPojo, wantedReturnType, new Params<>());
     }
 
-    <T> T put(String path, Optional<Object> bodyJsonPojo, Class<T> wantedReturnType, Params params);
+    <T> T put(String path, Optional<Object> bodyJsonPojo, Class<T> wantedReturnType, Params<T> params);
     default <T> T put(String path, Optional<Object> bodyJsonPojo, Class<T> wantedReturnType) {
-        return put(path, bodyJsonPojo, wantedReturnType, null);
+        return put(path, bodyJsonPojo, wantedReturnType, new Params<>());
     }
 
-    <T> T patch(String path, Object bodyJsonPojo, Class<T> wantedReturnType, Params params);
+    <T> T patch(String path, Object bodyJsonPojo, Class<T> wantedReturnType, Params<T> params);
     default <T> T patch(String path, Object bodyJsonPojo, Class<T> wantedReturnType) {
-        return patch(path, bodyJsonPojo, wantedReturnType, null);
+        return patch(path, bodyJsonPojo, wantedReturnType, new Params<>());
     }
 
-    <T> T delete(String path, Class<T> wantedReturnType, Params params);
+    <T> T delete(String path, Class<T> wantedReturnType, Params<T> params);
     default <T> T delete(String path, Class<T> wantedReturnType) {
-        return delete(path, wantedReturnType, null);
+        return delete(path, wantedReturnType, new Params<>());
     }
 
     /** Close the underlying HTTP client and any threads this class might have started. */