From 2344660bf14dc5f7c0ec17309816de0146659618 Mon Sep 17 00:00:00 2001
From: Smilencer <527646889@qq.com>
Date: Tue, 12 Jan 2021 18:16:20 +0800
Subject: [PATCH] feat(hotkey): dynamic change some parameters in hotkey
 detection (#679)

---
 rdsn                                        |  2 +-
 src/server/hotkey_collector.cpp             |  5 +++-
 src/server/hotspot_partition_calculator.cpp | 27 ++++++++++++---------
 3 files changed, 21 insertions(+), 13 deletions(-)

diff --git a/rdsn b/rdsn
index 5fe7ff16a5..ec34633e46 160000
--- a/rdsn
+++ b/rdsn
@@ -1 +1 @@
-Subproject commit 5fe7ff16a5ecd7656f04a8689637d27865678e33
+Subproject commit ec34633e4695e881209973460469b2b069c0f52e
diff --git a/src/server/hotkey_collector.cpp b/src/server/hotkey_collector.cpp
index 26ff59dee6..d59214deef 100644
--- a/src/server/hotkey_collector.cpp
+++ b/src/server/hotkey_collector.cpp
@@ -33,19 +33,21 @@ DSN_DEFINE_uint32(
     hot_bucket_variance_threshold,
     7,
     "the variance threshold to detect hot bucket during coarse analysis of hotkey detection");
+DSN_TAG_VARIABLE(hot_bucket_variance_threshold, FT_MUTABLE);
 
 DSN_DEFINE_uint32(
     "pegasus.server",
     hot_key_variance_threshold,
     5,
     "the variance threshold to detect hot key during fine analysis of hotkey detection");
+DSN_TAG_VARIABLE(hot_key_variance_threshold, FT_MUTABLE);
 
 DSN_DEFINE_uint32("pegasus.server",
                   hotkey_buckets_num,
                   37,
                   "the number of data capture hash buckets");
 
-DSN_DEFINE_validator(hotkey_buckets_num, [](int32_t bucket_num) -> bool {
+DSN_DEFINE_validator(hotkey_buckets_num, [](uint32_t bucket_num) -> bool {
     if (bucket_num < 3) {
         return false;
     }
@@ -63,6 +65,7 @@ DSN_DEFINE_uint32(
     max_seconds_to_detect_hotkey,
     150,
     "the max time (in seconds) allowed to capture hotkey, will stop if hotkey's not found");
+DSN_TAG_VARIABLE(max_seconds_to_detect_hotkey, FT_MUTABLE);
 
 // 68–95–99.7 rule, same algorithm as hotspot_partition_calculator::stat_histories_analyse
 /*extern*/ bool
diff --git a/src/server/hotspot_partition_calculator.cpp b/src/server/hotspot_partition_calculator.cpp
index 3b7086b695..68ad3dbc88 100644
--- a/src/server/hotspot_partition_calculator.cpp
+++ b/src/server/hotspot_partition_calculator.cpp
@@ -41,17 +41,20 @@ DSN_DEFINE_bool("pegasus.collector",
                 enable_detect_hotkey,
                 false,
                 "auto detect hot key in the hot paritition");
+DSN_TAG_VARIABLE(enable_detect_hotkey, FT_MUTABLE);
 
-DSN_DEFINE_int32("pegasus.collector",
-                 hot_partition_threshold,
-                 3,
-                 "threshold of hotspot partition value, if app.stat.hotspots >= "
-                 "FLAGS_hotpartition_threshold, this partition is a hot partition");
+DSN_DEFINE_uint32("pegasus.collector",
+                  hot_partition_threshold,
+                  3,
+                  "threshold of hotspot partition value, if app.stat.hotspots >= "
+                  "FLAGS_hotpartition_threshold, this partition is a hot partition");
+DSN_TAG_VARIABLE(hot_partition_threshold, FT_MUTABLE);
 
-DSN_DEFINE_int32("pegasus.collector",
-                 occurrence_threshold,
-                 3,
-                 "hot paritiotion occurrence times' threshold to send rpc to detect hotkey");
+DSN_DEFINE_uint32("pegasus.collector",
+                  occurrence_threshold,
+                  3,
+                  "hot paritiotion occurrence times' threshold to send rpc to detect hotkey");
+DSN_TAG_VARIABLE(occurrence_threshold, FT_MUTABLE);
 
 void hotspot_partition_calculator::data_aggregate(const std::vector<row_data> &partition_stats)
 {
@@ -149,9 +152,11 @@ void hotspot_partition_calculator::data_analyse()
 
 void hotspot_partition_calculator::detect_hotkey_in_hotpartition(int data_type)
 {
+    auto now_hot_partition_threshold = FLAGS_hot_partition_threshold;
+    auto now_occurrence_threshold = FLAGS_occurrence_threshold;
     for (int index = 0; index < _hot_points.size(); index++) {
-        if (_hot_points[index][data_type].get()->get_value() >= FLAGS_hot_partition_threshold) {
-            if (++_hotpartition_counter[index][data_type] >= FLAGS_occurrence_threshold) {
+        if (_hot_points[index][data_type].get()->get_value() >= now_hot_partition_threshold) {
+            if (++_hotpartition_counter[index][data_type] >= now_occurrence_threshold) {
                 derror_f("Find a {} hot partition {}.{}",
                          (data_type == partition_qps_type::READ_HOTSPOT_DATA ? "read" : "write"),
                          _app_name,