Improve exception message when DruidLeaderClient doesn't find leader …

…node (apache#14775) The existing exception message No known server thrown in DruidLeaderClient is unhelpful.
xvrl · Aug 10, 2023 · 4b9846b · 4b9846b
1 parent c8537db
commit 4b9846b
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Showing 2 changed files with 8 additions and 2 deletions.
diff --git a/server/src/main/java/org/apache/druid/discovery/DruidLeaderClient.java b/server/src/main/java/org/apache/druid/discovery/DruidLeaderClient.java
@@ -264,7 +264,11 @@ private String getCurrentKnownLeader(final boolean cached) throws IOException
     );
 
     if (leader == null) {
-      throw new IOE("No known server");
+      throw new IOE(
+          "A leader node could not be found for [%s] service. "
+          + "Check logs of service [%s] to confirm it is healthy.",
+          nodeRoleToWatch, nodeRoleToWatch
+      );
     } else {
       return leader;
     }

diff --git a/server/src/test/java/org/apache/druid/discovery/DruidLeaderClientTest.java b/server/src/test/java/org/apache/druid/discovery/DruidLeaderClientTest.java
@@ -159,7 +159,9 @@ public void testNoLeaderFound() throws Exception
     druidLeaderClient.start();
 
     expectedException.expect(IOException.class);
-    expectedException.expectMessage("No known server");
+    expectedException.expectMessage(
+        "A leader node could not be found for [PEON] service. "
+        + "Check logs of service [PEON] to confirm it is healthy.");
     druidLeaderClient.makeRequest(HttpMethod.POST, "/simple/direct");
   }