[kudu] 03/03: [metrics] make 'merged_entities_count_of_tablet' visible when only one entity merged

[al...@apache.org]

This is an automated email from the ASF dual-hosted git repository.

alexey pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/kudu.git

commit faae74ce4af6b0c30a7ebd4ff81233576b20162e
Author: zhangyifan27 <ch...@163.com>
AuthorDate: Thu Apr 9 19:27:32 2020 +0800

    [metrics] make 'merged_entities_count_of_tablet' visible when only one entity merged
    
    Before this patch, the metric 'merged_entities_count_of_tablet' is hidden
    when tablet server aggregate metrics by the same attribute and there is
    only one entity merged, because it's modification epoch is not updated.
    We should expose the metric in this condition.
    
    Change-Id: Ia74cae25b5bde7d61db1186e44abdff487d3f23f
    Reviewed-on: http://gerrit.cloudera.org:8080/15707
    Tested-by: Kudu Jenkins
    Reviewed-by: Alexey Serbin <as...@cloudera.com>
---
 src/kudu/tserver/tablet_server-test.cc | 13 +++++++++++++
 src/kudu/util/metrics.cc               |  3 +++
 2 files changed, 16 insertions(+)

diff --git a/src/kudu/tserver/tablet_server-test.cc b/src/kudu/tserver/tablet_server-test.cc
index 863534a..864032f 100644
--- a/src/kudu/tserver/tablet_server-test.cc
+++ b/src/kudu/tserver/tablet_server-test.cc
@@ -659,6 +659,19 @@ TEST_F(TabletServerTest, TestTombstonedTabletOnWebUI) {
   ASSERT_STR_NOT_CONTAINS(s, mini_server_->bound_rpc_addr().ToString());
 }
 
+// When tablet server merge metrics by the same attributes, the metric
+// 'merged_entities_count_of_tablet' should be visible
+TEST_F(TabletServerTest, TestMergedEntitiesCount) {
+  EasyCurl c;
+  faststring buf;
+  const string addr = mini_server_->bound_http_addr().ToString();
+  ASSERT_OK(c.FetchURL(Substitute("http://$0/metrics", addr), &buf));
+  ASSERT_STR_NOT_CONTAINS(buf.ToString(), "merged_entities_count_of_tablet");
+  ASSERT_OK(c.FetchURL(Substitute("http://$0/metrics?merge_rules=tablet|table|table_name", addr),
+                       &buf));
+  ASSERT_STR_CONTAINS(buf.ToString(), "merged_entities_count_of_tablet");
+}
+
 class TabletServerDiskSpaceTest : public TabletServerTestBase,
                                   public testing::WithParamInterface<string> {
  public:
diff --git a/src/kudu/util/metrics.cc b/src/kudu/util/metrics.cc
index f84edab..a48f870 100644
--- a/src/kudu/util/metrics.cc
+++ b/src/kudu/util/metrics.cc
@@ -426,6 +426,9 @@ Status MetricEntity::CollectTo(MergedEntityMetrics* collections,
     scoped_refptr<Metric> entry = FindPtrOrNull(entity_collection, prototype);
     if (!entry) {
       scoped_refptr<Metric> new_metric = metric->snapshot();
+      if (!new_metric->invalid_for_merge_) {
+        new_metric->UpdateModificationEpoch();
+      }
       InsertOrDie(&entity_collection, new_metric->prototype(), new_metric);
     } else {
       entry->MergeFrom(metric);