From ad0fe764f79f1d6d2cc493c9d5c8b975cd87be3c Mon Sep 17 00:00:00 2001
From: "Alexander A. Klimov" <alexander.klimov@icinga.com>
Date: Wed, 26 Jan 2022 12:35:41 +0100
Subject: [PATCH] Icinga DB: log amount of history kept in memory every 10s

---
 lib/base/bulker.hpp               |  5 +++++
 lib/icingadb/icingadb-objects.cpp | 21 +++++++++++++++++++++
 2 files changed, 26 insertions(+)

diff --git a/lib/base/bulker.hpp b/lib/base/bulker.hpp
index 711aae04f..2c30dc38b 100644
--- a/lib/base/bulker.hpp
+++ b/lib/base/bulker.hpp
@@ -38,6 +38,11 @@ public:
 	Container ConsumeMany();
 	SizeType Size();
 
+	inline SizeType GetBulkSize() const noexcept
+	{
+		return m_BulkSize;
+	}
+
 private:
 	typedef std::chrono::time_point<Clock> TimePoint;
 
diff --git a/lib/icingadb/icingadb-objects.cpp b/lib/icingadb/icingadb-objects.cpp
index 5f2117e57..265b78063 100644
--- a/lib/icingadb/icingadb-objects.cpp
+++ b/lib/icingadb/icingadb-objects.cpp
@@ -30,6 +30,7 @@
 #include "icinga/timeperiod.hpp"
 #include "icinga/pluginutility.hpp"
 #include "remote/zone.hpp"
+#include <chrono>
 #include <cstdint>
 #include <iterator>
 #include <map>
@@ -2264,7 +2265,25 @@ void IcingaDB::SendAcknowledgementCleared(const Checkable::Ptr& checkable, const
 
 void IcingaDB::ForwardHistoryEntries()
 {
+	using clock = std::chrono::steady_clock;
+
+	const std::chrono::seconds logInterval (10);
+	auto nextLog (clock::now() + logInterval);
+
+	auto logPeriodically ([this, logInterval, &nextLog]() {
+		if (clock::now() > nextLog) {
+			nextLog += logInterval;
+
+			auto size (m_HistoryBulker.Size());
+
+			Log(size > m_HistoryBulker.GetBulkSize() ? LogInformation : LogNotice, "IcingaDB")
+				<< "Pending history queries: " << size;
+		}
+	});
+
 	for (;;) {
+		logPeriodically();
+
 		auto haystack (m_HistoryBulker.ConsumeMany());
 
 		if (haystack.empty()) {
@@ -2288,6 +2307,8 @@ void IcingaDB::ForwardHistoryEntries()
 		});
 
 		for (;;) {
+			logPeriodically();
+
 			if (m_Rcon && m_Rcon->IsConnected()) {
 				try {
 					m_Rcon->GetResultsOfQueries(haystack, Prio::History);