Merge pull request #24906 from vbotbuildovich/backport-pr-24837-v24.3…

….x-319

[v24.3.x] Fix partitions local summary

src/v/redpanda/admin/partition.cc

@@ -724,7 +724,7 @@ void admin_server::register_partition_routes() {
                       if (it.second->get_leader_id() == std::nullopt) {
                           s.leaderless += 1;
                       }
-                      if (it.second->get_under_replicated() == std::nullopt) {
+                      if (it.second->get_under_replicated() > 0) {
                           s.under_replicated += 1;
                       }
                   }

tests/rptest/services/admin.py

@@ -1563,6 +1563,10 @@ def get_partition_state(self, namespace, topic, partition, node=None):
         path = f"debug/partition/{namespace}/{topic}/{partition}"
         return self._request("GET", path, node=node).json()
 
+    def get_partitions_local_summary(self, node: ClusterNode):
+        path = f"partitions/local_summary"
+        return self._request("GET", path, node=node).json()
+
     def get_producers_state(self, namespace, topic, partition, node=None):
         path = f"debug/producers/{namespace}/{topic}/{partition}"
         return self._request("GET", path, node=node).json()

tests/rptest/tests/partition_state_api_test.py

@@ -10,8 +10,13 @@
 from rptest.services.admin import Admin
 from rptest.tests.redpanda_test import RedpandaTest
 from rptest.services.cluster import cluster
+from rptest.clients.kafka_cli_tools import KafkaCliTools
 from rptest.clients.types import TopicSpec
 
+from collections import Counter
+import time
+import random
+
 
 class PartitionStateAPItest(RedpandaTest):
     def __init__(self, *args, **kwargs):
@@ -129,3 +134,68 @@ def test_controller_partition_state(self):
             leader_state = leaders[0]["raft_state"]
             assert "followers" in leader_state.keys() and len(
                 leader_state["followers"]) == 4
+
+    @cluster(num_nodes=5)
+    def test_local_summary(self):
+        admin = Admin(self.redpanda)
+        n_topics = 100
+        # allow for a couple of system partitions
+        tolerance = 2 * len(self.redpanda.nodes)
+
+        def produce():
+            kafka_tools = KafkaCliTools(self.redpanda)
+            for t in self.topics:
+                kafka_tools.produce(t.name, 1, 1, acks=1)
+
+        def sumsum_eventually(**expected):
+            self.logger.debug(f"{expected=}")
+
+            def check():
+                summaries = [
+                    Counter(admin.get_partitions_local_summary(n))
+                    for n in self.redpanda.started_nodes()
+                ]
+                self.logger.debug(f"{summaries=}")
+                ss = sum(summaries, Counter())
+                for k, v in expected.items():
+                    if ss[k] < v or ss[k] > v + tolerance:
+                        return False
+                return True
+
+            self.redpanda.wait_until(check, 30, 2,
+                                     "Unexpected local partition summaries")
+
+            time.sleep(5)
+            assert check()
+
+        def stop_one():
+            node_to_stop = random.choice(self.redpanda.started_nodes())
+            self.logger.debug(
+                f"Stopping node {self.redpanda.idx(node_to_stop)}")
+            self.redpanda.stop_node(node_to_stop)
+
+        self.topics = [
+            TopicSpec(partition_count=1,
+                      replication_factor=len(self.redpanda.nodes))
+            for _ in range(n_topics)
+        ]
+        self._create_initial_topics()
+
+        # all 5 nodes live
+        produce()
+        sumsum_eventually(count=5 * n_topics, leaderless=0, under_replicated=0)
+
+        # 3 out of 5 nodes to remain live
+        stop_one()
+        stop_one()
+        produce()
+        sumsum_eventually(count=3 * n_topics,
+                          leaderless=0,
+                          under_replicated=n_topics)
+
+        # 2 out of 5 nodes to remain live
+        produce()  # after stop we won't be able to produce into leaderless
+        stop_one()
+        sumsum_eventually(count=2 * n_topics,
+                          leaderless=2 * n_topics,
+                          under_replicated=0)