Merge branch 'jv-list-commits-oid-histogram' into 'master'

ListCommitsByOid: add histogram for request size

See merge request gitlab-org/gitaly!1650

1 files changed, 20 insertions, 0 deletions

diff --git a/internal/service/commit/list_commits_by_oid.go b/internal/service/commit/list_commits_by_oid.go
index c64e88792..614626055 100644
--- a/internal/service/commit/list_commits_by_oid.go
+++ b/internal/service/commit/list_commits_by_oid.go
@@ -5,8 +5,27 @@ import (
 	gitlog "gitlab.com/gitlab-org/gitaly/internal/git/log"
 	"gitlab.com/gitlab-org/gitaly/internal/helper/chunk"
 	"gitlab.com/gitlab-org/gitaly/proto/go/gitalypb"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+var (
+	listCommitsbyOidHistogram = prometheus.NewHistogram(
+		prometheus.HistogramOpts{
+			Name: "gitaly_list_commits_by_oid_request_size",
+			Help: "Number of commits requested in a ListCommitsByOid request",
+
+			// We want to count the pathological case where the request is empty. I
+			// am not sure if with floats, Observe(0) would go into bucket 0. Use
+			// bucket 0.001 because 0 <= 0.001 for sure.
+			Buckets: []float64{0.001, 1, 5, 10, 20},
+		})
 )
 
+func init() {
+	prometheus.MustRegister(listCommitsbyOidHistogram)
+}
+
 func (s *server) ListCommitsByOid(in *gitalypb.ListCommitsByOidRequest, stream gitalypb.CommitService_ListCommitsByOidServer) error {
 	ctx := stream.Context()
 
@@ -16,6 +35,7 @@ func (s *server) ListCommitsByOid(in *gitalypb.ListCommitsByOidRequest, stream g
 	}
 
 	sender := chunk.New(&commitsByOidSender{stream: stream})
+	listCommitsbyOidHistogram.Observe(float64(len(in.Oid)))
 
 	for _, oid := range in.Oid {
 		commit, err := gitlog.GetCommitCatfile(c, oid)