From 7bcd115371ce78908c2687d4492fa483e1bfd73d Mon Sep 17 00:00:00 2001
From: Lawrence Qiu <lawrenceqiu@google.com>
Date: Tue, 21 Apr 2026 16:54:50 -0400
Subject: [PATCH 1/6] feat(datastore): Update default channel pool configs to
 handle initial bursts and scalability

---
 .../google/cloud/datastore/DatastoreOptions.java | 16 +++++++++++-----
 .../cloud/datastore/spi/v1/GrpcDatastoreRpc.java | 14 +++++++++-----
 .../cloud/datastore/DatastoreOptionsTest.java    |  6 ++++++
 3 files changed, 26 insertions(+), 10 deletions(-)

diff --git a/java-datastore/google-cloud-datastore/src/main/java/com/google/cloud/datastore/DatastoreOptions.java b/java-datastore/google-cloud-datastore/src/main/java/com/google/cloud/datastore/DatastoreOptions.java
index 461252ac2980..8d8580df9d0a 100644
--- a/java-datastore/google-cloud-datastore/src/main/java/com/google/cloud/datastore/DatastoreOptions.java
+++ b/java-datastore/google-cloud-datastore/src/main/java/com/google/cloud/datastore/DatastoreOptions.java
@@ -54,7 +54,9 @@ public class DatastoreOptions extends ServiceOptions<Datastore, DatastoreOptions
   private static final String DEFAULT_DATABASE_ID = "";
   public static final String PROJECT_ID_ENV_VAR = "DATASTORE_PROJECT_ID";
   public static final String LOCAL_HOST_ENV_VAR = "DATASTORE_EMULATOR_HOST";
-  public static final int INIT_CHANNEL_COUNT = 1;
+  public static final int INIT_CHANNEL_COUNT = 5;
+  public static final int CHANNEL_POOL_DEFAULT_RESIZE_DELTA = 5;
+  public static final int CHANNEL_POOL_MAX_RPCS_PER_CHANNEL = 100;
   public static final int MIN_CHANNEL_COUNT = 1;
   public static final int MAX_CHANNEL_COUNT = 4;
 
@@ -233,14 +235,18 @@ private DatastoreOptions(Builder builder) {
           "Only gRPC transport allows setting of channel provider or credentials provider");
     } else if (getTransportOptions() instanceof GrpcTransportOptions) {
       if (builder.channelProvider == null) {
-        /*
-         The default gRPC connection pool is configured with a minimum of 1 channel.
-         The maximum channel count automatically defaults to 200 (Defined in gax-grpc).
-        */
+        // Set the default gRPC connection pool to be configured with a minimum of 1 channel.
+        // The maximum channel count automatically defaults to 200 (as defined in gax-grpc).
+        // Datastore sets the initial channel pool count to be 5 channels to allow better handle
+        // large loads of requests and the resize delta to be 5 to scale quicker. In cases of low
+        // load, the channel count will scale down as needed and memory will be freed. The default
+        // configuration is set to try and handle ~500 QPS and will scale up and down as needed.
         ChannelPoolSettings datastoreChannelPoolSettings =
             ChannelPoolSettings.builder()
                 .setInitialChannelCount(INIT_CHANNEL_COUNT)
                 .setMinChannelCount(MIN_CHANNEL_COUNT)
+                .setMaxRpcsPerChannel(CHANNEL_POOL_MAX_RPCS_PER_CHANNEL)
+                .setMaxResizeDelta(CHANNEL_POOL_DEFAULT_RESIZE_DELTA)
                 .build();
 
         ApiFunction<ManagedChannelBuilder, ManagedChannelBuilder> channelConfigurator =
diff --git a/java-datastore/google-cloud-datastore/src/main/java/com/google/cloud/datastore/spi/v1/GrpcDatastoreRpc.java b/java-datastore/google-cloud-datastore/src/main/java/com/google/cloud/datastore/spi/v1/GrpcDatastoreRpc.java
index cc5391dfee6a..89eec72342e8 100644
--- a/java-datastore/google-cloud-datastore/src/main/java/com/google/cloud/datastore/spi/v1/GrpcDatastoreRpc.java
+++ b/java-datastore/google-cloud-datastore/src/main/java/com/google/cloud/datastore/spi/v1/GrpcDatastoreRpc.java
@@ -27,6 +27,7 @@
 import com.google.api.gax.grpc.ChannelPoolSettings;
 import com.google.api.gax.grpc.GrpcCallContext;
 import com.google.api.gax.grpc.GrpcTransportChannel;
+import com.google.api.gax.grpc.InstantiatingGrpcChannelProvider;
 import com.google.api.gax.rpc.ClientContext;
 import com.google.api.gax.rpc.HeaderProvider;
 import com.google.api.gax.rpc.NoHeaderProvider;
@@ -80,13 +81,16 @@ public GrpcDatastoreRpc(DatastoreOptions datastoreOptions) throws IOException {
           DatastoreStubSettings.newBuilder(clientContext)
               .applyToAllUnaryMethods(retrySettingSetter(datastoreOptions));
       if (!isEmulator(datastoreOptions)) {
+        // Use the configured channel pool settings configured in the options. Datastore can
+        // make the assumption that this will always be a InstantiatingGrpcChannelProvider
+        // as the DatastoreOptions validates that the TransportChannelProvider is of the
+        // InstantiatingGrpcChannelProvider type
+        InstantiatingGrpcChannelProvider grpcChannelProvider =
+            (InstantiatingGrpcChannelProvider) datastoreOptions.getTransportChannelProvider();
+        ChannelPoolSettings channelPoolSettings = grpcChannelProvider.getChannelPoolSettings();
         datastoreStubSettingsBuilder.setTransportChannelProvider(
             DatastoreSettings.defaultGrpcTransportProviderBuilder()
-                .setChannelPoolSettings(
-                    ChannelPoolSettings.builder()
-                        .setInitialChannelCount(DatastoreOptions.INIT_CHANNEL_COUNT)
-                        .setMinChannelCount(DatastoreOptions.MIN_CHANNEL_COUNT)
-                        .build())
+                .setChannelPoolSettings(channelPoolSettings)
                 .build());
       }
 
diff --git a/java-datastore/google-cloud-datastore/src/test/java/com/google/cloud/datastore/DatastoreOptionsTest.java b/java-datastore/google-cloud-datastore/src/test/java/com/google/cloud/datastore/DatastoreOptionsTest.java
index 9e1df1abe4ec..43b23293774c 100644
--- a/java-datastore/google-cloud-datastore/src/test/java/com/google/cloud/datastore/DatastoreOptionsTest.java
+++ b/java-datastore/google-cloud-datastore/src/test/java/com/google/cloud/datastore/DatastoreOptionsTest.java
@@ -187,6 +187,12 @@ public void testGrpcDefaultChannelConfigurations() {
     assertEquals(channelPoolSettings.getInitialChannelCount(), DatastoreOptions.INIT_CHANNEL_COUNT);
     assertEquals(channelPoolSettings.getMinChannelCount(), DatastoreOptions.MIN_CHANNEL_COUNT);
     assertEquals(channelPoolSettings.getMaxChannelCount(), DEFAULT_MAX_CHANNEL_COUNT);
+    assertEquals(
+        channelPoolSettings.getMaxResizeDelta(),
+        DatastoreOptions.CHANNEL_POOL_DEFAULT_RESIZE_DELTA);
+    assertEquals(
+        channelPoolSettings.getMaxRpcsPerChannel(),
+        DatastoreOptions.CHANNEL_POOL_MAX_RPCS_PER_CHANNEL);
   }
 
   @Test

From 7bc97f7233901acb7a829bc9e40aaf77c1f73aba Mon Sep 17 00:00:00 2001
From: Lawrence Qiu <lawrenceqiu@google.com>
Date: Tue, 21 Apr 2026 17:23:46 -0400
Subject: [PATCH 2/6] chore: Add ObsoleteApi annotation to unused public
 constant

---
 .../main/java/com/google/cloud/datastore/DatastoreOptions.java | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/java-datastore/google-cloud-datastore/src/main/java/com/google/cloud/datastore/DatastoreOptions.java b/java-datastore/google-cloud-datastore/src/main/java/com/google/cloud/datastore/DatastoreOptions.java
index 8d8580df9d0a..3bd35d7d1678 100644
--- a/java-datastore/google-cloud-datastore/src/main/java/com/google/cloud/datastore/DatastoreOptions.java
+++ b/java-datastore/google-cloud-datastore/src/main/java/com/google/cloud/datastore/DatastoreOptions.java
@@ -20,6 +20,7 @@
 
 import com.google.api.core.ApiFunction;
 import com.google.api.core.BetaApi;
+import com.google.api.core.ObsoleteApi;
 import com.google.api.gax.grpc.ChannelPoolSettings;
 import com.google.api.gax.grpc.InstantiatingGrpcChannelProvider;
 import com.google.api.gax.rpc.TransportChannelProvider;
@@ -58,6 +59,8 @@ public class DatastoreOptions extends ServiceOptions<Datastore, DatastoreOptions
   public static final int CHANNEL_POOL_DEFAULT_RESIZE_DELTA = 5;
   public static final int CHANNEL_POOL_MAX_RPCS_PER_CHANNEL = 100;
   public static final int MIN_CHANNEL_COUNT = 1;
+
+  @ObsoleteApi("This constant is obsolete and will be removed in a future version")
   public static final int MAX_CHANNEL_COUNT = 4;
 
   private transient TransportChannelProvider channelProvider = null;

From 11346a36aadf6d2b7e84c63fcfd5ee283ab9f323 Mon Sep 17 00:00:00 2001
From: Lawrence Qiu <lawrenceqiu@google.com>
Date: Tue, 21 Apr 2026 17:28:11 -0400
Subject: [PATCH 3/6] chore: set new channel pool defaults as package-private

---
 .../java/com/google/cloud/datastore/DatastoreOptions.java     | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/java-datastore/google-cloud-datastore/src/main/java/com/google/cloud/datastore/DatastoreOptions.java b/java-datastore/google-cloud-datastore/src/main/java/com/google/cloud/datastore/DatastoreOptions.java
index 3bd35d7d1678..0e5d63220388 100644
--- a/java-datastore/google-cloud-datastore/src/main/java/com/google/cloud/datastore/DatastoreOptions.java
+++ b/java-datastore/google-cloud-datastore/src/main/java/com/google/cloud/datastore/DatastoreOptions.java
@@ -56,8 +56,8 @@ public class DatastoreOptions extends ServiceOptions<Datastore, DatastoreOptions
   public static final String PROJECT_ID_ENV_VAR = "DATASTORE_PROJECT_ID";
   public static final String LOCAL_HOST_ENV_VAR = "DATASTORE_EMULATOR_HOST";
   public static final int INIT_CHANNEL_COUNT = 5;
-  public static final int CHANNEL_POOL_DEFAULT_RESIZE_DELTA = 5;
-  public static final int CHANNEL_POOL_MAX_RPCS_PER_CHANNEL = 100;
+  static final int CHANNEL_POOL_DEFAULT_RESIZE_DELTA = 5;
+  static final int CHANNEL_POOL_MAX_RPCS_PER_CHANNEL = 100;
   public static final int MIN_CHANNEL_COUNT = 1;
 
   @ObsoleteApi("This constant is obsolete and will be removed in a future version")

From 7638bb7345068617088833ed7750de39ece67328 Mon Sep 17 00:00:00 2001
From: Lawrence Qiu <lawrenceqiu@google.com>
Date: Tue, 21 Apr 2026 17:34:52 -0400
Subject: [PATCH 4/6] chore: Add comment to explain the
 CHANNEL_POOL_MAX_RPCS_PER_CHANNEL constant

---
 .../java/com/google/cloud/datastore/DatastoreOptions.java     | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/java-datastore/google-cloud-datastore/src/main/java/com/google/cloud/datastore/DatastoreOptions.java b/java-datastore/google-cloud-datastore/src/main/java/com/google/cloud/datastore/DatastoreOptions.java
index 0e5d63220388..38dfd2fd94f5 100644
--- a/java-datastore/google-cloud-datastore/src/main/java/com/google/cloud/datastore/DatastoreOptions.java
+++ b/java-datastore/google-cloud-datastore/src/main/java/com/google/cloud/datastore/DatastoreOptions.java
@@ -57,6 +57,10 @@ public class DatastoreOptions extends ServiceOptions<Datastore, DatastoreOptions
   public static final String LOCAL_HOST_ENV_VAR = "DATASTORE_EMULATOR_HOST";
   public static final int INIT_CHANNEL_COUNT = 5;
   static final int CHANNEL_POOL_DEFAULT_RESIZE_DELTA = 5;
+
+  // Configure this default to be 100 to match the typical default `MAX_CONCURRENT_STREAMS`.
+  // Larger values *may* experience possible client-side queueing as excess streams cannot be
+  // multiplexed onto a full Http2 connection.
   static final int CHANNEL_POOL_MAX_RPCS_PER_CHANNEL = 100;
   public static final int MIN_CHANNEL_COUNT = 1;
 

From ba94173320a5d8d66faf7a74596131bbe3e8a1d7 Mon Sep 17 00:00:00 2001
From: Lawrence Qiu <lawrenceqiu@google.com>
Date: Wed, 22 Apr 2026 12:01:18 -0400
Subject: [PATCH 5/6] chore: Address PR feedback

---
 .../cloud/datastore/DatastoreOptions.java     | 29 +++++++------------
 .../datastore/spi/v1/GrpcDatastoreRpc.java    | 16 +++-------
 2 files changed, 14 insertions(+), 31 deletions(-)

diff --git a/java-datastore/google-cloud-datastore/src/main/java/com/google/cloud/datastore/DatastoreOptions.java b/java-datastore/google-cloud-datastore/src/main/java/com/google/cloud/datastore/DatastoreOptions.java
index 38dfd2fd94f5..70d1c568ec95 100644
--- a/java-datastore/google-cloud-datastore/src/main/java/com/google/cloud/datastore/DatastoreOptions.java
+++ b/java-datastore/google-cloud-datastore/src/main/java/com/google/cloud/datastore/DatastoreOptions.java
@@ -18,7 +18,6 @@
 
 import static com.google.cloud.datastore.Validator.validateNamespace;
 
-import com.google.api.core.ApiFunction;
 import com.google.api.core.BetaApi;
 import com.google.api.core.ObsoleteApi;
 import com.google.api.gax.grpc.ChannelPoolSettings;
@@ -38,7 +37,6 @@
 import com.google.cloud.http.HttpTransportOptions;
 import com.google.common.base.MoreObjects;
 import com.google.common.collect.ImmutableSet;
-import io.grpc.ManagedChannelBuilder;
 import java.io.IOException;
 import java.lang.reflect.Method;
 import java.util.Objects;
@@ -57,15 +55,16 @@ public class DatastoreOptions extends ServiceOptions<Datastore, DatastoreOptions
   public static final String LOCAL_HOST_ENV_VAR = "DATASTORE_EMULATOR_HOST";
   public static final int INIT_CHANNEL_COUNT = 5;
   static final int CHANNEL_POOL_DEFAULT_RESIZE_DELTA = 5;
-
   // Configure this default to be 100 to match the typical default `MAX_CONCURRENT_STREAMS`.
   // Larger values *may* experience possible client-side queueing as excess streams cannot be
   // multiplexed onto a full Http2 connection.
   static final int CHANNEL_POOL_MAX_RPCS_PER_CHANNEL = 100;
   public static final int MIN_CHANNEL_COUNT = 1;
 
+  // This is a default max channel constant value set to handle the default initial channel
+  // count and resize delta.
   @ObsoleteApi("This constant is obsolete and will be removed in a future version")
-  public static final int MAX_CHANNEL_COUNT = 4;
+  public static final int MAX_CHANNEL_COUNT = 10;
 
   private transient TransportChannelProvider channelProvider = null;
 
@@ -256,23 +255,15 @@ private DatastoreOptions(Builder builder) {
                 .setMaxResizeDelta(CHANNEL_POOL_DEFAULT_RESIZE_DELTA)
                 .build();
 
-        ApiFunction<ManagedChannelBuilder, ManagedChannelBuilder> channelConfigurator =
-            this.traceUtil.getChannelConfigurator();
-        if (channelConfigurator == null) {
-          this.channelProvider =
-              GrpcTransportOptions.setUpChannelProvider(
-                  DatastoreSettings.defaultGrpcTransportProviderBuilder()
-                      .setChannelPoolSettings(datastoreChannelPoolSettings),
-                  this);
-        } else {
+        InstantiatingGrpcChannelProvider.Builder channelProviderBuilder =
+            DatastoreSettings.defaultGrpcTransportProviderBuilder()
+                .setChannelPoolSettings(datastoreChannelPoolSettings)
+                .setEndpoint(getHost());
+        if (traceUtil.getChannelConfigurator() != null) {
           // Intercept the grpc channel calls to add telemetry info.
-          this.channelProvider =
-              GrpcTransportOptions.setUpChannelProvider(
-                  DatastoreSettings.defaultGrpcTransportProviderBuilder()
-                      .setChannelPoolSettings(datastoreChannelPoolSettings)
-                      .setChannelConfigurator(channelConfigurator),
-                  this);
+          channelProviderBuilder.setChannelConfigurator(traceUtil.getChannelConfigurator());
         }
+        this.channelProvider = channelProviderBuilder.build();
       } else {
         this.channelProvider = builder.channelProvider;
       }
diff --git a/java-datastore/google-cloud-datastore/src/main/java/com/google/cloud/datastore/spi/v1/GrpcDatastoreRpc.java b/java-datastore/google-cloud-datastore/src/main/java/com/google/cloud/datastore/spi/v1/GrpcDatastoreRpc.java
index 89eec72342e8..f952dfdc9ef0 100644
--- a/java-datastore/google-cloud-datastore/src/main/java/com/google/cloud/datastore/spi/v1/GrpcDatastoreRpc.java
+++ b/java-datastore/google-cloud-datastore/src/main/java/com/google/cloud/datastore/spi/v1/GrpcDatastoreRpc.java
@@ -24,10 +24,8 @@
 import com.google.api.core.InternalApi;
 import com.google.api.gax.core.BackgroundResource;
 import com.google.api.gax.core.GaxProperties;
-import com.google.api.gax.grpc.ChannelPoolSettings;
 import com.google.api.gax.grpc.GrpcCallContext;
 import com.google.api.gax.grpc.GrpcTransportChannel;
-import com.google.api.gax.grpc.InstantiatingGrpcChannelProvider;
 import com.google.api.gax.rpc.ClientContext;
 import com.google.api.gax.rpc.HeaderProvider;
 import com.google.api.gax.rpc.NoHeaderProvider;
@@ -81,17 +79,11 @@ public GrpcDatastoreRpc(DatastoreOptions datastoreOptions) throws IOException {
           DatastoreStubSettings.newBuilder(clientContext)
               .applyToAllUnaryMethods(retrySettingSetter(datastoreOptions));
       if (!isEmulator(datastoreOptions)) {
-        // Use the configured channel pool settings configured in the options. Datastore can
-        // make the assumption that this will always be a InstantiatingGrpcChannelProvider
-        // as the DatastoreOptions validates that the TransportChannelProvider is of the
-        // InstantiatingGrpcChannelProvider type
-        InstantiatingGrpcChannelProvider grpcChannelProvider =
-            (InstantiatingGrpcChannelProvider) datastoreOptions.getTransportChannelProvider();
-        ChannelPoolSettings channelPoolSettings = grpcChannelProvider.getChannelPoolSettings();
+        // Use the TransportChannelProvider configured in DatastoreOptions. For gRPC transport, this
+        // will
+        // be configured with a default ChannelPool configuration
         datastoreStubSettingsBuilder.setTransportChannelProvider(
-            DatastoreSettings.defaultGrpcTransportProviderBuilder()
-                .setChannelPoolSettings(channelPoolSettings)
-                .build());
+            datastoreOptions.getTransportChannelProvider());
       }
 
       datastoreStub = GrpcDatastoreStub.create(datastoreStubSettingsBuilder.build());

From 37b70fbef88222068a4307813b0a5b749eb1ff71 Mon Sep 17 00:00:00 2001
From: Lawrence Qiu <lawrenceqiu@google.com>
Date: Wed, 22 Apr 2026 12:15:51 -0400
Subject: [PATCH 6/6] chore: Remove test for package-private resize delta
 getter

---
 .../java/com/google/cloud/datastore/DatastoreOptionsTest.java  | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/java-datastore/google-cloud-datastore/src/test/java/com/google/cloud/datastore/DatastoreOptionsTest.java b/java-datastore/google-cloud-datastore/src/test/java/com/google/cloud/datastore/DatastoreOptionsTest.java
index 43b23293774c..79e9ab965aa1 100644
--- a/java-datastore/google-cloud-datastore/src/test/java/com/google/cloud/datastore/DatastoreOptionsTest.java
+++ b/java-datastore/google-cloud-datastore/src/test/java/com/google/cloud/datastore/DatastoreOptionsTest.java
@@ -187,9 +187,6 @@ public void testGrpcDefaultChannelConfigurations() {
     assertEquals(channelPoolSettings.getInitialChannelCount(), DatastoreOptions.INIT_CHANNEL_COUNT);
     assertEquals(channelPoolSettings.getMinChannelCount(), DatastoreOptions.MIN_CHANNEL_COUNT);
     assertEquals(channelPoolSettings.getMaxChannelCount(), DEFAULT_MAX_CHANNEL_COUNT);
-    assertEquals(
-        channelPoolSettings.getMaxResizeDelta(),
-        DatastoreOptions.CHANNEL_POOL_DEFAULT_RESIZE_DELTA);
     assertEquals(
         channelPoolSettings.getMaxRpcsPerChannel(),
         DatastoreOptions.CHANNEL_POOL_MAX_RPCS_PER_CHANNEL);