[router] RouterExceptionAndTrackingUtils allocation reduction (#1413)

Removed all Optionals from RouterExceptionAndTrackingUtils.

Miscellaneous:

- Tweaked flaky unit test RouterRequestThrottlingTest.

- Deleted a disabled test in TestZKStore.

- Tweaked the main README page.

docs/README.md

@@ -137,8 +137,9 @@ Feel free to engage with the community using our:
 - [<img src="assets/icons/github-icon.svg" width="15" />](./dev_guide/how_to/how_to.md) [Contributor's guide](./dev_guide/how_to/how_to.md)
 
 Follow us to hear more about the progress of the Venice project and community:
-- [<img src="assets/icons/hashnode-icon.svg" width="15" />](https://blog.venicedb.org) [Official blog](https://blog.venicedb.org)
+- [<img src="assets/icons/hashnode-icon.svg" width="15" />](https://blog.venicedb.org) [Blog](https://blog.venicedb.org)
+- [<img src="assets/icons/bluesky-icon.svg" width="15" />](https://bsky.app/profile/venicedb.org) [Bluesky handle](https://bsky.app/profile/venicedb.org)
 - [<img src="assets/icons/linkedin-icon.svg" width="15" />](https://www.linkedin.com/company/venicedb) [LinkedIn page](https://www.linkedin.com/company/venicedb)
-- [<img src="assets/icons/x-icon.svg" width="15" />](https://x.com/VeniceDataBase) [X page](https://x.com/VeniceDataBase)
+- [<img src="assets/icons/x-icon.svg" width="15" />](https://x.com/VeniceDataBase) [X handle](https://x.com/VeniceDataBase)
 - [<img src="assets/icons/youtube-icon.svg" width="15" />](https://youtube.com/@venicedb) [YouTube channel](https://youtube.com/@venicedb)
 

internal/venice-client-common/src/main/java/com/linkedin/venice/HttpConstants.java

@@ -23,6 +23,11 @@ public class HttpConstants {
   public static final String VENICE_RETRY = "X-VENICE-RETRY";
 
   public static final String VENICE_COMPRESSION_STRATEGY = "X-VENICE-COMPRESSION-STRATEGY";
+  /**
+   * N.B.: There seems to be an assumption that this header's value will contain just a single compression scheme (GZIP)
+   *       and that it's not correct to pass a list of supported compression strategies (as one might expect). So we
+   *       need to be careful if we ever intend to evolve the way this header is used to accommodate multiple schemes.
+   */
   public static final String VENICE_SUPPORTED_COMPRESSION_STRATEGY = "X-VENICE-SUPPORTED-COMPRESSION-STRATEGY";
 
   public static final String VENICE_STREAMING = "X-VENICE-STREAMING";

internal/venice-common/src/test/java/com/linkedin/venice/meta/TestZKStore.java

@@ -395,34 +395,6 @@ public void invalidStoreNameThrows() {
         1);
   }
 
-  /**
-   * We're not relying on push ID uniqueness.  We can reenable this test if we start relying on (and enforcing) push ID uniqueness
-   */
-  @Test(groups = { "flaky" })
-  public void cannotAddDifferentVersionsWithSamePushId() {
-    String storeName = "storeName";
-    Store store = new ZKStore(
-        storeName,
-        "owner",
-        System.currentTimeMillis(),
-        PersistenceType.IN_MEMORY,
-        RoutingStrategy.CONSISTENT_HASH,
-        ReadStrategy.ANY_OF_ONLINE,
-        OfflinePushStrategy.WAIT_N_MINUS_ONE_REPLCIA_PER_PARTITION,
-        1);
-    String duplicatePushJobId = "pushId";
-    Version versionOne = new VersionImpl(storeName, 1, duplicatePushJobId);
-    store.addVersion(versionOne);
-    Version versionTwo = new VersionImpl(storeName, 2, duplicatePushJobId);
-    try {
-      store.addVersion(versionTwo);
-      Assert.fail("Store must not allow adding a new version with same pushId");
-    } catch (Exception e) {
-      // expected
-      LOGGER.info("Expected exception: {}", e.getLocalizedMessage());
-    }
-  }
-
   @Test
   public void testStoreLevelAcl() {
     Store store = new ZKStore(

internal/venice-test-common/src/integrationTest/java/com/linkedin/venice/integration/utils/MockVeniceRouterWrapper.java

@@ -84,6 +84,7 @@ static StatefulServiceProvider<MockVeniceRouterWrapper> generateService(
     doReturn(CompressionStrategy.NO_OP).when(mockStore).getCompressionStrategy();
     HelixReadOnlyStoreRepository mockMetadataRepository = Mockito.mock(HelixReadOnlyStoreRepository.class);
     doReturn(mockStore).when(mockMetadataRepository).getStore(Mockito.anyString());
+    doReturn(mockStore).when(mockMetadataRepository).getStoreOrThrow(Mockito.anyString());
 
     Version mockVersion = Mockito.mock(Version.class);
     doReturn(mockVersion).when(mockStore).getVersion(Mockito.anyInt());

internal/venice-test-common/src/main/java/com/linkedin/venice/utils/TestUtils.java

@@ -11,7 +11,6 @@
 import static org.mockito.Mockito.eq;
 import static org.mockito.Mockito.mock;
 import static org.testng.Assert.assertEquals;
-import static org.testng.Assert.assertNotNull;
 import static org.testng.Assert.assertTrue;
 
 import com.github.luben.zstd.Zstd;
@@ -46,7 +45,6 @@
 import com.linkedin.venice.helix.SafeHelixManager;
 import com.linkedin.venice.helix.VeniceOfflinePushMonitorAccessor;
 import com.linkedin.venice.kafka.protocol.state.PartitionState;
-import com.linkedin.venice.meta.DataReplicationPolicy;
 import com.linkedin.venice.meta.IngestionMode;
 import com.linkedin.venice.meta.Instance;
 import com.linkedin.venice.meta.OfflinePushStrategy;
@@ -656,23 +654,6 @@ public static void verifyDCConfigNativeAndActiveRepl(
     });
   }
 
-  public static void verifyHybridStoreDataReplicationPolicy(
-      String storeName,
-      DataReplicationPolicy dataReplicationPolicy,
-      ControllerClient... controllerClients) {
-    TestUtils.waitForNonDeterministicAssertion(60, TimeUnit.SECONDS, true, () -> {
-      for (ControllerClient controllerClient: controllerClients) {
-        StoreResponse storeResponse = assertCommand(controllerClient.getStore(storeName));
-        assertNotNull(storeResponse.getStore(), "Store should not be null");
-        assertNotNull(storeResponse.getStore().getHybridStoreConfig(), "Hybrid store config should not be null");
-        assertEquals(
-            storeResponse.getStore().getHybridStoreConfig().getDataReplicationPolicy(),
-            dataReplicationPolicy,
-            "The data replication policy does not match.");
-      }
-    });
-  }
-
   public static StoreIngestionTaskFactory.Builder getStoreIngestionTaskBuilder(String storeName) {
     VeniceServerConfig mockVeniceServerConfig = mock(VeniceServerConfig.class);
     doReturn(false).when(mockVeniceServerConfig).isHybridQuotaEnabled();