From 39ce5434558b4f2b1d7c6863b23f402c4cab5e23 Mon Sep 17 00:00:00 2001
From: Qi Tan <16416018+TQJADE@users.noreply.github.com>
Date: Thu, 18 Jun 2026 09:45:40 -0700
Subject: [PATCH 1/2] parallelize InformerManager changeNamespaces

InformerManager#changeNamespaces starts informers for newly added
namespaces sequentially via Set#forEach. Each source.start() call
blocks up to cacheSyncTimeout waiting for cache sync, so when N
namespaces are added and any of them are slow or RBAC-denied (a
common case under stopOnInformerErrorDuringStartup=false), the
total wall-clock is O(N * cacheSyncTimeout). The Controller holds
its EventProcessor stopped across this entire call, dropping watch
events with "Skipping event ... because the event processor is not
started" and producing multi-minute reconcile delays after dynamic
namespace updates.

Align changeNamespaces with the existing parallel pattern already
used by InformerManager#start (boundedExecuteAndWaitForAllToComplete
on the caching executor). Wall-clock drops from O(N * timeout) to
O(timeout). The sources map is already a ConcurrentHashMap, so no
additional synchronization is required.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Revert "178463593 test"

This reverts commit c3550e41e9bfbf3bc3619257aa0bb26ae46ac2dc.

Signed-off-by: Qi Tan <16416018+TQJADE@users.noreply.github.com>
---
 .../source/informer/InformerManager.java      | 30 ++++++++++++++-----
 1 file changed, 22 insertions(+), 8 deletions(-)

diff --git a/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/event/source/informer/InformerManager.java b/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/event/source/informer/InformerManager.java
index a0b7938302..32e9286078 100644
--- a/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/event/source/informer/InformerManager.java
+++ b/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/event/source/informer/InformerManager.java
@@ -113,14 +113,28 @@ public void changeNamespaces(Set<String> namespaces) {
     log.debug("Stopped informer {} for namespaces: {}", this, sourcesToRemove);
     sourcesToRemove.forEach(k -> sources.remove(k).stop());
 
-    namespaces.forEach(
-        ns -> {
-          if (!sources.containsKey(ns)) {
-            final InformerWrapper<R> source = createEventSourceForNamespace(ns);
-            source.start();
-            log.debug("Registered new {} -> {} for namespace: {}", this, source, ns);
-          }
-        });
+    var newNamespaces =
+        namespaces.stream().filter(ns -> !sources.containsKey(ns)).collect(Collectors.toList());
+    if (newNamespaces.isEmpty()) {
+      return;
+    }
+
+    controllerConfiguration
+        .getConfigurationService()
+        .getExecutorServiceManager()
+        .boundedExecuteAndWaitForAllToComplete(
+            newNamespaces.stream(),
+            ns -> {
+              final InformerWrapper<R> source = createEventSourceForNamespace(ns);
+              source.start();
+              log.debug("Registered new {} -> {} for namespace: {}", this, source, ns);
+              return null;
+            },
+            ns ->
+                "InformerStarter-"
+                    + ns
+                    + "-"
+                    + configuration.getResourceClass().getSimpleName());
   }
 
   private InformerWrapper<R> createEventSourceForNamespace(String namespace) {

From 35ef37681a9140511fbd5fd8196427e50ea8e641 Mon Sep 17 00:00:00 2001
From: Qi Tan <16416018+TQJADE@users.noreply.github.com>
Date: Fri, 19 Jun 2026 09:20:44 -0700
Subject: [PATCH 2/2] Address comments

Signed-off-by: Qi Tan <16416018+TQJADE@users.noreply.github.com>
---
 .../processing/event/source/informer/InformerManager.java | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/event/source/informer/InformerManager.java b/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/event/source/informer/InformerManager.java
index 32e9286078..bfbe17c7c8 100644
--- a/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/event/source/informer/InformerManager.java
+++ b/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/event/source/informer/InformerManager.java
@@ -125,16 +125,12 @@ public void changeNamespaces(Set<String> namespaces) {
         .boundedExecuteAndWaitForAllToComplete(
             newNamespaces.stream(),
             ns -> {
-              final InformerWrapper<R> source = createEventSourceForNamespace(ns);
+              final var source = createEventSourceForNamespace(ns);
               source.start();
               log.debug("Registered new {} -> {} for namespace: {}", this, source, ns);
               return null;
             },
-            ns ->
-                "InformerStarter-"
-                    + ns
-                    + "-"
-                    + configuration.getResourceClass().getSimpleName());
+            ns -> "InformerStarter-" + ns + "-" + configuration.getResourceClass().getSimpleName());
   }
 
   private InformerWrapper<R> createEventSourceForNamespace(String namespace) {