From d79022e473a3f3a02adbb18e23fa8dd1ed5a7e95 Mon Sep 17 00:00:00 2001
From: Tomasz Grabiec <tgrabiec@scylladb.com>
Date: Thu, 7 May 2026 14:33:01 +0200
Subject: [PATCH] api: failure_detector: Introduce convict-node API

Add POST /failure_detector/convict/{host} endpoint that forces local
failure detection of a given host, marking it as DOWN and dropping
connections.

Will be used in tests to speed up failure detection after killing a
node, avoiding the ~20s natural failure detection delay.
---
 api/api-doc/failure_detector.json | 24 ++++++++++++++++++++++++
 api/failure_detector.cc           | 13 +++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/api/api-doc/failure_detector.json b/api/api-doc/failure_detector.json
index c59e7630b4..dd3408c570 100644
--- a/api/api-doc/failure_detector.json
+++ b/api/api-doc/failure_detector.json
@@ -7,6 +7,30 @@
       "application/json"
    ],
    "apis":[
+      {
+         "path":"/failure_detector/convict/{host}",
+         "operations":[
+            {
+               "method":"POST",
+               "summary":"Forces failure detection of a given host locally, marks the node as DOWN, drops connections",
+               "type":"string",
+               "nickname":"convict",
+               "produces":[
+                  "application/json"
+               ],
+               "parameters":[
+                  {
+                     "name":"host",
+                     "description":"Host ID of the node to convict",
+                     "required":true,
+                     "allowMultiple":false,
+                     "type":"string",
+                     "paramType":"path"
+                  }
+               ]
+            }
+         ]
+      },
       {
          "path":"/failure_detector/phi",
          "operations":[
diff --git a/api/failure_detector.cc b/api/failure_detector.cc
index 76a8626341..9076ceac7c 100644
--- a/api/failure_detector.cc
+++ b/api/failure_detector.cc
@@ -9,9 +9,12 @@
 #include "failure_detector.hh"
 #include "api/api.hh"
 #include "api/api-doc/failure_detector.json.hh"
+#include "api/validate.hh"
 #include "gms/application_state.hh"
 #include "gms/gossiper.hh"
 
+extern logging::logger apilog;
+
 namespace api {
 using namespace seastar::httpd;
 
@@ -64,6 +67,15 @@ void set_failure_detector(http_context& ctx, routes& r, gms::gossiper& g) {
         return make_ready_future<json::json_return_type>(8);
     });
 
+    fd::convict.set(r, [&g] (std::unique_ptr<request> req) -> future<json::json_return_type> {
+        return g.container().invoke_on(0, [req = std::move(req)] (gms::gossiper& g) -> future<json::json_return_type> {
+            auto host_id = validate_host_id(req->get_path_param("host"));
+            apilog.info("Convict {}", host_id);
+            co_await g.convict(host_id);
+            co_return seastar::json::json_void();
+        });
+    });
+
     fd::get_simple_states.set(r, [&g] (std::unique_ptr<request> req) {
         return g.container().invoke_on(0, [] (gms::gossiper& g) {
             std::vector<fd::mapper> nodes_status;
@@ -114,6 +126,7 @@ void unset_failure_detector(http_context& ctx, routes& r) {
     fd::set_phi_convict_threshold.unset(r);
     fd::get_endpoint_state.unset(r);
     fd::get_endpoint_phi_values.unset(r);
+    fd::convict.unset(r);
 }
 
 }