From 6d90eebfb99f8dc970b561cb82ef7f83d76c2a68 Mon Sep 17 00:00:00 2001
From: Amnon Heiman <amnon@cloudius-systems.com>
Date: Thu, 8 Oct 2015 14:55:02 +0300
Subject: [PATCH] column family: Add estimated histogram impl

This patch adds the read and write latency estimated histogram support
and add an estimatd histogram to the number of sstable that were used in
a read.

Signed-off-by: Amnon Heiman <amnon@cloudius-systems.com>
---
 database.cc | 3 +++
 database.hh | 7 +++++++
 2 files changed, 10 insertions(+)

diff --git a/database.cc b/database.cc
index dc956d6be7..f5976261dc 100644
--- a/database.cc
+++ b/database.cc
@@ -1337,6 +1337,9 @@ column_family::query(const query::read_command& cmd, const std::vector<query::pa
         });
     }).finally([lc, this]() mutable {
         _stats.reads.mark(lc);
+        if (lc.is_start()) {
+            _stats.estimated_read.add(lc.latency_in_nano(), _stats.reads.count);
+        }
     });
 }
 
diff --git a/database.hh b/database.hh
index 813c2bdbfb..53f0d16248 100644
--- a/database.hh
+++ b/database.hh
@@ -125,6 +125,7 @@ public:
         utils::ihistogram writes{256};
         sstables::estimated_histogram estimated_read;
         sstables::estimated_histogram estimated_write;
+        sstables::estimated_histogram estimated_sstable_per_read;
     };
 
 private:
@@ -586,6 +587,9 @@ column_family::apply(const mutation& m, const db::replay_position& rp) {
     active_memtable().apply(m, rp);
     seal_on_overflow();
     _stats.writes.mark(lc);
+    if (lc.is_start()) {
+        _stats.estimated_write.add(lc.latency_in_nano(), _stats.writes.count);
+    }
 }
 
 inline
@@ -617,6 +621,9 @@ column_family::apply(const frozen_mutation& m, const db::replay_position& rp) {
     active_memtable().apply(m, rp);
     seal_on_overflow();
     _stats.writes.mark(lc);
+    if (lc.is_start()) {
+        _stats.estimated_write.add(lc.latency_in_nano(), _stats.writes.count);
+    }
 }
 
 future<> update_schema_version_and_announce(distributed<service::storage_proxy>& proxy);