From 236ae841063c98836383e9e62f9e2ec6f3067f79 Mon Sep 17 00:00:00 2001
From: Yinnan Yao <35447132+yaoyinnan@users.noreply.github.com>
Date: Wed, 19 Jul 2023 15:31:35 +0800
Subject: [PATCH] fix: remove instantaneous_metric and collect network metrics
 every 5 seconds (#1757)

Remove the instantaneous_metric thread and use DoTimingTask() to collect network traffic every 5 seconds.

Fixes: #1756

Signed-off-by: yaoyinnan <yaoyinnan@foxmail.com>
---
 include/pika_server.h                         |  2 +-
 src/pika_instant.cc                           |  2 +-
 src/pika_server.cc                            | 14 ++++----------
 tools/pika_exporter/exporter/metrics/stats.go |  8 ++++----
 4 files changed, 10 insertions(+), 16 deletions(-)

diff --git a/include/pika_server.h b/include/pika_server.h
index 138df54ec4..3f79d3e3cd 100644
--- a/include/pika_server.h
+++ b/include/pika_server.h
@@ -508,7 +508,7 @@ class PikaServer : public pstd::noncopyable {
   void AutoPurge();
   void AutoDeleteExpiredDump();
   void AutoKeepAliveRSync();
-  void AutoInstantaneousMetric();
+  void AutoUpdateNetworkMetric();
 
   std::string host_;
   int port_ = 0;
diff --git a/src/pika_instant.cc b/src/pika_instant.cc
index 1592cbf9dd..b2e33287fb 100644
--- a/src/pika_instant.cc
+++ b/src/pika_instant.cc
@@ -17,7 +17,7 @@ double Instant::getInstantaneousMetric(std::string metric) {
   return sum / STATS_METRIC_SAMPLES;
 }
 
-/* ======================= Cron: called every 100 ms ======================== */
+/* ======================= Cron: called every 5 s ======================== */
 
 /* Add a sample to the instantaneous metric. This function computes the quotient
  * of the increment of value and base, which is useful to record operation count
diff --git a/src/pika_server.cc b/src/pika_server.cc
index 704ec0f215..8e7765747e 100644
--- a/src/pika_server.cc
+++ b/src/pika_server.cc
@@ -190,14 +190,6 @@ void PikaServer::Start() {
   }
   LOG(INFO) << "Pika Server going to start";
 
-  // Auto update instantaneous metric
-  std::thread instantaneous_metric([&]() {
-    while (!exit_) {
-      AutoInstantaneousMetric();
-      // wake up every 100 milliseconds
-      std::this_thread::sleep_for(std::chrono::milliseconds(100));
-    }
-  });
 
   while (!exit_) {
     DoTimingTask();
@@ -1313,6 +1305,8 @@ void PikaServer::DoTimingTask() {
   AutoKeepAliveRSync();
   // Reset server qps
   ResetLastSecQuerynum();
+  // Auto update network instantaneous metric
+  AutoUpdateNetworkMetric();
 }
 
 void PikaServer::AutoCompactRange() {
@@ -1493,9 +1487,9 @@ void PikaServer::AutoKeepAliveRSync() {
   }
 }
 
-void PikaServer::AutoInstantaneousMetric() {
+void PikaServer::AutoUpdateNetworkMetric() {
   monotime current_time = getMonotonicUs();
-  size_t factor = 1000000; // us
+  size_t factor = 5e6; // us, 5s
   instant_->trackInstantaneousMetric(STATS_METRIC_NET_INPUT, g_pika_server->NetInputBytes() + g_pika_server->NetReplInputBytes(),
                                     current_time, factor);
   instant_->trackInstantaneousMetric(STATS_METRIC_NET_OUTPUT, g_pika_server->NetOutputBytes() + g_pika_server->NetReplOutputBytes(),
diff --git a/tools/pika_exporter/exporter/metrics/stats.go b/tools/pika_exporter/exporter/metrics/stats.go
index dd0816fa84..a1fc59633d 100644
--- a/tools/pika_exporter/exporter/metrics/stats.go
+++ b/tools/pika_exporter/exporter/metrics/stats.go
@@ -81,7 +81,7 @@ var collectStatsMetrics = map[string]MetricConfig{
         Parser: &normalParser{},
         MetricMeta: &MetaData{
             Name:      "instantaneous_input_kbps",
-            Help:      "the network's read rate per second in KB/sec",
+            Help:      "the network's read rate per second in KB/sec, calculated as an average of 16 samples collected every 5 seconds.",
             Type:      metricTypeCounter,
             Labels:    []string{LabelNameAddr, LabelNameAlias},
             ValueName: "instantaneous_input_kbps",
@@ -91,7 +91,7 @@ var collectStatsMetrics = map[string]MetricConfig{
         Parser: &normalParser{},
         MetricMeta: &MetaData{
             Name:      "instantaneous_output_kbps",
-            Help:      "the network's write rate per second in KB/sec",
+            Help:      "the network's write rate per second in KB/sec, calculated as an average of 16 samples collected every 5 seconds.",
             Type:      metricTypeCounter,
             Labels:    []string{LabelNameAddr, LabelNameAlias},
             ValueName: "instantaneous_output_kbps",
@@ -101,7 +101,7 @@ var collectStatsMetrics = map[string]MetricConfig{
         Parser: &normalParser{},
         MetricMeta: &MetaData{
             Name:      "instantaneous_input_repl_kbps",
-            Help:      "the network's read rate per second in KB/sec for replication purposes",
+            Help:      "the network's read rate per second in KB/sec for replication purposes, calculated as an average of 16 samples collected every 5 seconds.",
             Type:      metricTypeCounter,
             Labels:    []string{LabelNameAddr, LabelNameAlias},
             ValueName: "instantaneous_input_repl_kbps",
@@ -111,7 +111,7 @@ var collectStatsMetrics = map[string]MetricConfig{
         Parser: &normalParser{},
         MetricMeta: &MetaData{
             Name:      "instantaneous_output_repl_kbps",
-            Help:      "the network's write rate per second in KB/sec for replication purposes",
+            Help:      "the network's write rate per second in KB/sec for replication purposes, calculated as an average of 16 samples collected every 5 seconds.",
             Type:      metricTypeCounter,
             Labels:    []string{LabelNameAddr, LabelNameAlias},
             ValueName: "instantaneous_output_repl_kbps",