Monitoring: Clean up MonitoringIT

We recently reenabled MonitoringIT to hunt down #29880 but some of its
assertions were out of date. This updates the assertions.

Author: nik9000

x-pack/plugin/monitoring/src/test/java/org/elasticsearch/xpack/monitoring/integration/MonitoringIT.java

@@ -67,6 +67,7 @@
 import static org.elasticsearch.threadpool.ThreadPool.Names.WRITE;
 import static org.elasticsearch.xpack.core.monitoring.exporter.MonitoringTemplateUtils.TEMPLATE_VERSION;
 import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.empty;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.greaterThan;
 import static org.hamcrest.Matchers.greaterThanOrEqualTo;
@@ -339,7 +340,7 @@ private void assertClusterStatsMonitoringDoc(final Map<String, Object> document,
 
         final Map<String, Object> clusterStats = (Map<String, Object>) source.get("cluster_stats");
         assertThat(clusterStats, notNullValue());
-        assertThat(clusterStats.size(), equalTo(4));
+        assertThat(clusterStats.size(), equalTo(5));
 
         final Map<String, Object> stackStats = (Map<String, Object>) source.get("stack_stats");
         assertThat(stackStats, notNullValue());
@@ -349,7 +350,7 @@ private void assertClusterStatsMonitoringDoc(final Map<String, Object> document,
         assertThat(apm, notNullValue());
         assertThat(apm.size(), equalTo(1));
         assertThat(apm.remove("found"), is(apmIndicesExist));
-        assertThat(apm.isEmpty(), is(true));
+        assertThat(apm.keySet(), empty());
 
         final Map<String, Object> xpackStats = (Map<String, Object>) stackStats.get("xpack");
         assertThat(xpackStats, notNullValue());
@@ -361,14 +362,14 @@ private void assertClusterStatsMonitoringDoc(final Map<String, Object> document,
 
         final Map<String, Object> clusterState = (Map<String, Object>) source.get("cluster_state");
         assertThat(clusterState, notNullValue());
-        assertThat(clusterState.size(), equalTo(6));
         assertThat(clusterState.remove("nodes_hash"), notNullValue());
         assertThat(clusterState.remove("status"), notNullValue());
         assertThat(clusterState.remove("version"), notNullValue());
         assertThat(clusterState.remove("state_uuid"), notNullValue());
+        assertThat(clusterState.remove("cluster_uuid"), notNullValue());
         assertThat(clusterState.remove("master_node"), notNullValue());
         assertThat(clusterState.remove("nodes"), notNullValue());
-        assertThat(clusterState.isEmpty(), is(true));
+        assertThat(clusterState.keySet(), empty());
     }
 
     /**
@@ -454,6 +455,11 @@ private void assertNodeStatsMonitoringDoc(final Map<String, Object> document) {
                 return;
             }
 
+            // bulk is not a thread pool in the current version but we allow it to support mixed version clusters
+            if (filter.startsWith("node_stats.thread_pool.bulk")) {
+                return;
+            }
+
             assertThat(filter + " must not be null in the monitoring document", extractValue(filter, source), notNullValue());
         });
     }