From 192c1949a36d9d8313be65ada2aa8735c0779677 Mon Sep 17 00:00:00 2001
From: Benny Halevy <bhalevy@scylladb.com>
Date: Sun, 12 Aug 2018 16:35:58 +0300
Subject: [PATCH] sstables stats: partition seeks

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
---
 sstables/partition.cc | 5 ++++-
 sstables/sstables.cc  | 2 ++
 sstables/stats.hh     | 5 +++++
 3 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/sstables/partition.cc b/sstables/partition.cc
index 0fc9aa84c3..4c953e3f43 100644
--- a/sstables/partition.cc
+++ b/sstables/partition.cc
@@ -269,7 +269,9 @@ private:
                 return make_ready_future<>();
             }
             assert(_index_reader->element_kind() == indexable_element::partition);
-            return _context->skip_to(_index_reader->element_kind(), start);
+            return _context->skip_to(_index_reader->element_kind(), start).then([this] {
+                _sst->get_stats().on_partition_seek();
+            });
         });
     }
     future<> read_from_index() {
@@ -381,6 +383,7 @@ private:
                     return make_ready_future<>();
                 }
                 return _context->skip_to(idx.element_kind(), index_position.start).then([this, &idx] {
+                    _sst->get_stats().on_partition_seek();
                     set_range_tombstone_start_from_end_open_marker(_consumer, *_schema, idx);
                 });
             });
diff --git a/sstables/sstables.cc b/sstables/sstables.cc
index a59f88b87f..a1e0368f62 100644
--- a/sstables/sstables.cc
+++ b/sstables/sstables.cc
@@ -4300,6 +4300,8 @@ future<> init_metrics() {
             sm::description("Number of whole sstable flat mutation reads")),
         sm::make_derive("partition_reads", [] { return sstables_stats::get_shard_stats().partition_reads; },
             sm::description("Number of partitions read")),
+        sm::make_derive("partition_seeks", [] { return sstables_stats::get_shard_stats().partition_seeks; },
+            sm::description("Number of partitions seeked")),
     });
   });
 }
diff --git a/sstables/stats.hh b/sstables/stats.hh
index 03593d1a33..a9d1ba206d 100644
--- a/sstables/stats.hh
+++ b/sstables/stats.hh
@@ -36,6 +36,7 @@ class sstables_stats {
         uint64_t range_partition_reads = 0;
         uint64_t sstable_partition_reads = 0;
         uint64_t partition_reads = 0;
+        uint64_t partition_seeks = 0;
     } _shard_stats;
 
     stats& _stats = _shard_stats;
@@ -88,6 +89,10 @@ public:
     inline void on_partition_read() {
         ++_stats.partition_reads;
     }
+
+    inline void on_partition_seek() {
+        ++_stats.partition_seeks;
+    }
 };
 
 }