Retry on all SocketExceptions

Author: nicktindall

modules/repository-gcs/src/main/java/org/elasticsearch/repositories/gcs/GoogleCloudStorageService.java

@@ -41,6 +41,7 @@
 import java.io.InputStreamReader;
 import java.net.HttpURLConnection;
 import java.net.Proxy;
+import java.net.SocketException;
 import java.net.URI;
 import java.net.URL;
 import java.net.UnknownHostException;
@@ -275,6 +276,10 @@ protected StorageRetryStrategy getRetryStrategy() {
                 if (ExceptionsHelper.unwrap(prevThrowable, UnknownHostException.class) != null) {
                     return true;
                 }
+                // Also retry on `SocketException`s
+                if (ExceptionsHelper.unwrap(prevThrowable, SocketException.class) != null) {
+                    return true;
+                }
                 return delegate.shouldRetry(prevThrowable, prevResponse);
             }
         );

modules/repository-gcs/src/test/java/org/elasticsearch/repositories/gcs/GoogleCloudStorageBlobContainerRetriesTests.java

@@ -449,13 +449,17 @@ public void testWriteLargeBlob() throws IOException {
                         return;
                     }
                 }
-
-                exchange.sendResponseHeaders(HttpStatus.SC_INTERNAL_SERVER_ERROR, -1);
             } else {
                 ExceptionsHelper.maybeDieOnAnotherThread(
                     new AssertionError("Unexpected request" + exchange.getRequestMethod() + " " + exchange.getRequestURI())
                 );
             }
+
+            if (randomBoolean()) {
+                exchange.sendResponseHeaders(HttpStatus.SC_INTERNAL_SERVER_ERROR, -1);
+            } else {
+                logger.warn("Closing connection without response");
+            }
         }));
 
         if (randomBoolean()) {