Propagate errors quicker

2 files changed, 79 insertions, 3 deletions

diff --git a/container-search/src/main/java/com/yahoo/prelude/fastsearch/FS4SearchInvoker.java b/container-search/src/main/java/com/yahoo/prelude/fastsearch/FS4SearchInvoker.java
index ae0a29aa80b..856de8d33ef 100644
--- a/container-search/src/main/java/com/yahoo/prelude/fastsearch/FS4SearchInvoker.java
+++ b/container-search/src/main/java/com/yahoo/prelude/fastsearch/FS4SearchInvoker.java
@@ -61,15 +61,20 @@ public class FS4SearchInvoker extends SearchInvoker implements ResponseMonitor<F
         try {
             boolean couldSend = channel.sendPacket(queryPacket);
             if (!couldSend) {
-                pendingSearchError = ErrorMessage.createBackendCommunicationError("Could not reach '" + getName() + "'");
+                setPendingError("Could not reach '" + getName() + "'");
             }
         } catch (InvalidChannelException e) {
-            pendingSearchError = ErrorMessage.createBackendCommunicationError("Invalid channel " + getName());
+            setPendingError("Invalid channel " + getName());
         } catch (IllegalStateException e) {
-            pendingSearchError = ErrorMessage.createBackendCommunicationError("Illegal state in FS4: " + e.getMessage());
+            setPendingError("Illegal state in FS4: " + e.getMessage());
         }
     }
 
+    private void setPendingError(String message) {
+        pendingSearchError = ErrorMessage.createBackendCommunicationError(message);
+        responseAvailable();
+    }
+
     @Override
     protected Result getSearchResult(CacheKey cacheKey, Execution execution) throws IOException {
         if (pendingSearchError != null) {
diff --git a/container-search/src/test/java/com/yahoo/prelude/fastsearch/FS4SearchInvokerTestCase.java b/container-search/src/test/java/com/yahoo/prelude/fastsearch/FS4SearchInvokerTestCase.java
new file mode 100644
index 00000000000..4a78d4e7631
--- /dev/null
+++ b/container-search/src/test/java/com/yahoo/prelude/fastsearch/FS4SearchInvokerTestCase.java
@@ -0,0 +1,71 @@
+package com.yahoo.prelude.fastsearch;
+
+import com.yahoo.fs4.BasicPacket;
+import com.yahoo.fs4.QueryPacket;
+import com.yahoo.fs4.mplex.FS4Channel;
+import com.yahoo.fs4.mplex.InvalidChannelException;
+import com.yahoo.search.Query;
+import com.yahoo.search.Result;
+import com.yahoo.search.dispatch.InterleavedSearchInvoker;
+import com.yahoo.search.dispatch.MockSearchCluster;
+import com.yahoo.search.dispatch.ResponseMonitor;
+import com.yahoo.search.searchchain.Execution;
+import org.hamcrest.Matchers;
+import org.junit.Test;
+
+import java.io.IOException;
+import java.util.Collections;
+import java.util.Optional;
+
+import static org.junit.Assert.assertThat;
+
+public class FS4SearchInvokerTestCase {
+    @SuppressWarnings("resource")
+    @Test
+    public void testThatConnectionErrorsAreReportedImmediately() throws IOException {
+        var query = new Query("?");
+        query.setTimeout(1000);
+
+        var searcher = mockSearcher();
+        var cluster = new MockSearchCluster("?", 1, 1);
+        var fs4invoker = new FS4SearchInvoker(searcher, query, mockFailingChannel(), Optional.empty());
+        var interleave = new InterleavedSearchInvoker(Collections.singleton(fs4invoker), searcher, cluster);
+
+        long start = System.currentTimeMillis();
+        interleave.search(query, QueryPacket.create(null, null), null, null);
+        long elapsed = System.currentTimeMillis() - start;
+
+        assertThat("Connection error should fail fast", elapsed, Matchers.lessThan(500L));
+    }
+
+    private static VespaBackEndSearcher mockSearcher() {
+        return new VespaBackEndSearcher() {
+            @Override
+            protected Result doSearch2(Query query, QueryPacket queryPacket, CacheKey cacheKey, Execution execution) {
+                return null;
+            }
+
+            @Override
+            protected void doPartialFill(Result result, String summaryClass) {}
+        };
+    }
+
+    private static FS4Channel mockFailingChannel() {
+        return new FS4Channel() {
+            @Override
+            public boolean sendPacket(BasicPacket packet) throws InvalidChannelException, IOException {
+                // pretend there's a connection error
+                return false;
+            }
+
+            @Override
+            public void setQuery(Query q) {}
+
+            @Override
+            public void setResponseMonitor(ResponseMonitor<FS4Channel> monitor) {}
+
+            @Override
+            public void close() {}
+        };
+    }
+}