diff --git a/util/src/main/java/io/kubernetes/client/informer/SharedInformerFactory.java b/util/src/main/java/io/kubernetes/client/informer/SharedInformerFactory.java
index ea6b5dfdf7..79ce9349b7 100644
--- a/util/src/main/java/io/kubernetes/client/informer/SharedInformerFactory.java
+++ b/util/src/main/java/io/kubernetes/client/informer/SharedInformerFactory.java
@@ -31,9 +31,7 @@
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.Future;
-import java.util.concurrent.TimeUnit;
 import okhttp3.Call;
-import okhttp3.OkHttpClient;
 import org.apache.commons.collections4.MapUtils;
 
 /** SharedInformerFactory class constructs and caches informers for api types. */
@@ -49,7 +47,7 @@ public class SharedInformerFactory {
 
   /** Constructor w/ default thread pool. */
   public SharedInformerFactory() {
-    this(Configuration.getDefaultApiClient(), Executors.newCachedThreadPool());
+    this(Configuration.getDefaultApiClient().setReadTimeout(0), Executors.newCachedThreadPool());
   }
 
   /** Constructor w/ api client specified and default thread pool. */
@@ -63,7 +61,7 @@ public SharedInformerFactory(ApiClient apiClient) {
    * @param threadPool specified thread pool
    */
   public SharedInformerFactory(ExecutorService threadPool) {
-    this(Configuration.getDefaultApiClient(), threadPool);
+    this(Configuration.getDefaultApiClient().setReadTimeout(0), threadPool);
   }
 
   /**
@@ -73,6 +71,10 @@ public SharedInformerFactory(ExecutorService threadPool) {
    * @param threadPool specified thread pool
    */
   public SharedInformerFactory(ApiClient client, ExecutorService threadPool) {
+    if (client.getReadTimeout() != 0) {
+      throw new IllegalArgumentException("read timeout of ApiClient must be zero");
+    }
+
     apiClient = client;
     informerExecutor = threadPool;
     informers = new HashMap<>();
@@ -169,11 +171,9 @@ ListerWatcher<ApiType, ApiListType> listerWatcherFor(
           CallGenerator callGenerator,
           Class<ApiType> apiTypeClass,
           Class<ApiListType> apiListTypeClass) {
-    if (apiClient.getHttpClient().readTimeoutMillis() > 0) {
+    if (apiClient.getReadTimeout() > 0) {
       // set read timeout zero to ensure client doesn't time out
-      OkHttpClient httpClient =
-          apiClient.getHttpClient().newBuilder().readTimeout(0, TimeUnit.MILLISECONDS).build();
-      apiClient.setHttpClient(httpClient);
+      apiClient.setReadTimeout(0);
     }
     return new ListerWatcher<ApiType, ApiListType>() {
       @Override
@@ -185,6 +185,8 @@ public ApiListType list(CallGeneratorParams params) throws ApiException {
       @Override
       public Watch<ApiType> watch(CallGeneratorParams params) throws ApiException {
         Call call = callGenerator.generate(params);
+        // bind call with private http client to make sure read timeout is zero.
+        call = apiClient.getHttpClient().newCall(call.request());
         return Watch.createWatch(
             apiClient,
             call,
@@ -196,12 +198,11 @@ public Watch<ApiType> watch(CallGeneratorParams params) throws ApiException {
   private <ApiType extends KubernetesObject, ApiListType extends KubernetesListObject>
       ListerWatcher<ApiType, ApiListType> listerWatcherFor(
           GenericKubernetesApi<ApiType, ApiListType> genericKubernetesApi) {
-    if (apiClient.getHttpClient().readTimeoutMillis() > 0) {
+    if (apiClient.getReadTimeout() > 0) {
       // set read timeout zero to ensure client doesn't time out
-      OkHttpClient httpClient =
-          apiClient.getHttpClient().newBuilder().readTimeout(0, TimeUnit.MILLISECONDS).build();
-      apiClient.setHttpClient(httpClient);
+      apiClient.setReadTimeout(0);
     }
+    // TODO: it seems read timeout is determined by genericKubernetesApi instead of above apiClient.
     return new ListerWatcher<ApiType, ApiListType>() {
       public ApiListType list(CallGeneratorParams params) throws ApiException {
         return genericKubernetesApi
diff --git a/util/src/main/java/io/kubernetes/client/informer/cache/DeltaFIFO.java b/util/src/main/java/io/kubernetes/client/informer/cache/DeltaFIFO.java
index c8220cd3dc..af4e1b4c85 100644
--- a/util/src/main/java/io/kubernetes/client/informer/cache/DeltaFIFO.java
+++ b/util/src/main/java/io/kubernetes/client/informer/cache/DeltaFIFO.java
@@ -29,6 +29,7 @@
 import java.util.function.Consumer;
 import java.util.function.Function;
 import org.apache.commons.collections4.CollectionUtils;
+import org.apache.commons.lang3.StringUtils;
 import org.apache.commons.lang3.tuple.MutablePair;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -443,7 +444,22 @@ private Deque<MutablePair<DeltaType, KubernetesObject>> combineDeltas(
    */
   private MutablePair<DeltaType, KubernetesObject> isDuplicate(
       MutablePair<DeltaType, KubernetesObject> d1, MutablePair<DeltaType, KubernetesObject> d2) {
-    return isDeletionDup(d1, d2);
+    MutablePair<DeltaType, KubernetesObject> deletionDelta = isDeletionDup(d1, d2);
+
+    // TODO: remove this after the cause of memory leakage is confirmed
+    // Squashing deltas w/ the same resource version, note that is a temporary fix that eases memory
+    // intensity.
+    if (deletionDelta != null) {
+      return deletionDelta;
+    }
+    if (d1.getLeft() != DeltaType.Deleted
+        && d2.getLeft() != DeltaType.Deleted
+        && StringUtils.equals(
+            d1.getRight().getMetadata().getResourceVersion(),
+            d2.getRight().getMetadata().getResourceVersion())) {
+      return d1;
+    }
+    return null;
   }
 
   /**
diff --git a/util/src/test/java/io/kubernetes/client/informer/cache/DeltaFIFOTest.java b/util/src/test/java/io/kubernetes/client/informer/cache/DeltaFIFOTest.java
index 39b7d0fba5..2e8a3d2873 100644
--- a/util/src/test/java/io/kubernetes/client/informer/cache/DeltaFIFOTest.java
+++ b/util/src/test/java/io/kubernetes/client/informer/cache/DeltaFIFOTest.java
@@ -20,6 +20,7 @@
 import io.kubernetes.client.openapi.models.V1ObjectMeta;
 import io.kubernetes.client.openapi.models.V1Pod;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.Deque;
 import java.util.LinkedList;
 import org.apache.commons.lang3.tuple.MutablePair;
@@ -94,7 +95,9 @@ public void testDeltaFIFOBasic() throws InterruptedException {
 
   @Test
   public void testDeltaFIFODedup() {
-    V1Pod foo1 = new V1Pod().metadata(new V1ObjectMeta().name("foo1").namespace("default"));
+    V1Pod foo1 =
+        new V1Pod()
+            .metadata(new V1ObjectMeta().name("foo1").namespace("default").resourceVersion("ver"));
     Cache cache = new Cache();
     DeltaFIFO deltaFIFO = new DeltaFIFO(Caches::deletionHandlingMetaNamespaceKeyFunc, cache);
     Deque<MutablePair<DeltaFIFO.DeltaType, KubernetesObject>> deltas;
@@ -121,6 +124,12 @@ public void testDeltaFIFODedup() {
     assertEquals(foo1, deltas.peekFirst().getRight());
     assertEquals(2, deltas.size());
     deltaFIFO.getItems().remove(Caches.deletionHandlingMetaNamespaceKeyFunc(foo1));
+
+    // add-sync dedupe
+    deltaFIFO.add(foo1);
+    deltaFIFO.replace(Collections.singletonList(foo1), foo1.getMetadata().getResourceVersion());
+    deltas = deltaFIFO.getItems().get(Caches.deletionHandlingMetaNamespaceKeyFunc(foo1));
+    assertEquals(1, deltas.size());
   }
 
   @Test