From cd2e786d72c3f36154a387f402662bdd91cdf7de Mon Sep 17 00:00:00 2001
From: Andrii Patsula <andriy.patsula@gmail.com>
Date: Mon, 12 Dec 2022 19:44:05 +0100
Subject: [PATCH] Report a warning when a server's IP cannot be found in ping.

Fixes #12156
Closes #12206
---
 service/raft/raft_group_registry.cc | 4 ++++
 service/raft/raft_group_registry.hh | 3 +++
 2 files changed, 7 insertions(+)

diff --git a/service/raft/raft_group_registry.cc b/service/raft/raft_group_registry.cc
index 0f351e01e0..7b4f80dd4b 100644
--- a/service/raft/raft_group_registry.cc
+++ b/service/raft/raft_group_registry.cc
@@ -445,6 +445,10 @@ future<bool> direct_fd_pinger::ping(direct_failure_detector::pinger::endpoint_id
     auto dst_id = raft::server_id{std::move(id)};
     auto addr = _address_map.find(dst_id);
     if (!addr) {
+        auto [it, _] = _rate_limits.try_emplace(id, std::chrono::minutes(5));
+        auto& rate_limit = it->second;
+
+        rslog.log(log_level::warn, rate_limit, "Raft server id {} cannot be translated to an IP address.", id);
         co_return false;
     }
 
diff --git a/service/raft/raft_group_registry.hh b/service/raft/raft_group_registry.hh
index e5fa06b8f8..ad0af8643c 100644
--- a/service/raft/raft_group_registry.hh
+++ b/service/raft/raft_group_registry.hh
@@ -149,6 +149,9 @@ class direct_fd_pinger : public seastar::peering_sharded_service<direct_fd_pinge
     netw::messaging_service& _ms;
     raft_address_map& _address_map;
 
+    using rate_limits = std::unordered_map<direct_failure_detector::pinger::endpoint_id, logger::rate_limit>;
+    rate_limits _rate_limits;
+
 public:
     direct_fd_pinger(netw::messaging_service& ms, raft_address_map& address_map)
             : _ms(ms), _address_map(address_map) {}