From f719099a2c3c382c2b5ebd4aa6250dffcf1cb1cb Mon Sep 17 00:00:00 2001
From: robot-clickhouse <robot-clickhouse@users.noreply.github.com>
Date: Thu, 14 Nov 2024 16:07:34 +0000
Subject: [PATCH] Backport #71863 to 24.8: update host resolver a little bit
 often

---
 src/Common/HostResolvePool.cpp | 19 +++++++++++--------
 src/Common/HostResolvePool.h   |  4 ++--
 2 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/src/Common/HostResolvePool.cpp b/src/Common/HostResolvePool.cpp
index e8a05a269bc..2c5bf039fe5 100644
--- a/src/Common/HostResolvePool.cpp
+++ b/src/Common/HostResolvePool.cpp
@@ -9,6 +9,7 @@
 
 #include <mutex>
 #include <algorithm>
+#include <Poco/Timespan.h>
 
 
 namespace ProfileEvents
@@ -49,16 +50,18 @@ HostResolver::WeakPtr HostResolver::getWeakFromThis()
 }
 
 HostResolver::HostResolver(String host_, Poco::Timespan history_)
-    : host(std::move(host_))
-    , history(history_)
-    , resolve_function([](const String & host_to_resolve) { return DNSResolver::instance().resolveHostAllInOriginOrder(host_to_resolve); })
-{
-    update();
-}
+    : HostResolver(
+        [](const String & host_to_resolve) { return DNSResolver::instance().resolveHostAllInOriginOrder(host_to_resolve); },
+        host_,
+        history_)
+{}
 
 HostResolver::HostResolver(
     ResolveFunction && resolve_function_, String host_, Poco::Timespan history_)
-    : host(std::move(host_)), history(history_), resolve_function(std::move(resolve_function_))
+    : host(std::move(host_))
+    , history(history_)
+    , resolve_interval(history_.totalMicroseconds() / 3)
+    , resolve_function(std::move(resolve_function_))
 {
     update();
 }
@@ -203,7 +206,7 @@ bool HostResolver::isUpdateNeeded()
     Poco::Timestamp now;
 
     std::lock_guard lock(mutex);
-    return last_resolve_time + history < now || records.empty();
+    return last_resolve_time + resolve_interval < now || records.empty();
 }
 
 void HostResolver::updateImpl(Poco::Timestamp now, std::vector<Poco::Net::IPAddress> & next_gen)
diff --git a/src/Common/HostResolvePool.h b/src/Common/HostResolvePool.h
index d148e909ca9..b979da3d142 100644
--- a/src/Common/HostResolvePool.h
+++ b/src/Common/HostResolvePool.h
@@ -26,7 +26,7 @@
 //    a) it still occurs in resolve set after `history_` time or b) all other addresses are pessimized as well.
 // - resolve schedule
 //    Addresses are resolved through `DB::DNSResolver::instance()`.
-//    Usually it does not happen more often than once in `history_` time.
+//    Usually it does not happen more often than 3 times in `history_` period.
 //    But also new resolve performed each `setFail()` call.
 
 namespace DB
@@ -212,6 +212,7 @@ protected:
 
     const String host;
     const Poco::Timespan history;
+    const Poco::Timespan resolve_interval;
     const HostResolverMetrics metrics = getMetrics();
 
     // for tests purpose
@@ -245,4 +246,3 @@ private:
 };
 
 }
-