[HUDI-9315] Add Hudi Timeline UI to aid debugging

hudi-common/src/main/java/org/apache/hudi/common/table/timeline/dto/v2/InstantDTO.java

@@ -0,0 +1,62 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.hudi.common.table.timeline.dto.v2;
+
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import org.apache.hudi.common.table.timeline.HoodieInstant;
+import org.apache.hudi.common.table.timeline.InstantGenerator;
+
+/**
+ * The data transfer object of instant.
+ */
+@JsonIgnoreProperties(ignoreUnknown = true)
+public class InstantDTO {
+
+  @JsonProperty("action")
+  String action;
+  @JsonProperty("requestTs")
+  String requestedTime;
+  @JsonProperty("completionTs")
+  String completionTime;
+  @JsonProperty("state")
+  String state;
+
+  public static InstantDTO fromInstant(HoodieInstant instant) {
+    if (null == instant) {
+      return null;
+    }
+
+    InstantDTO dto = new InstantDTO();
+    dto.action = instant.getAction();
+    dto.requestedTime = instant.requestedTime();
+    dto.completionTime = instant.getCompletionTime();
+    dto.state = instant.getState().toString();
+    return dto;
+  }
+
+  public static HoodieInstant toInstant(InstantDTO dto, InstantGenerator factory) {
+    if (null == dto) {
+      return null;
+    }
+
+    return factory.createNewInstant(HoodieInstant.State.valueOf(dto.state), dto.action,
+        dto.requestedTime, dto.completionTime);
+  }
+}

hudi-common/src/main/java/org/apache/hudi/common/table/timeline/dto/v2/TimelineDTO.java

@@ -0,0 +1,52 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.hudi.common.table.timeline.dto.v2;
+
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import java.util.List;
+import java.util.stream.Collectors;
+import org.apache.hudi.common.table.HoodieTableMetaClient;
+import org.apache.hudi.common.table.timeline.HoodieTimeline;
+import org.apache.hudi.common.table.timeline.InstantGenerator;
+import org.apache.hudi.common.table.timeline.TimelineFactory;
+
+/**
+ * The data transfer object of timeline.
+ */
+@JsonIgnoreProperties(ignoreUnknown = true)
+public class TimelineDTO {
+
+  @JsonProperty("instants")
+  List<InstantDTO> instants;
+
+  public static TimelineDTO fromTimeline(HoodieTimeline timeline) {
+    TimelineDTO dto = new TimelineDTO();
+    dto.instants = timeline.getInstantsAsStream().map(InstantDTO::fromInstant).collect(Collectors.toList());
+    return dto;
+  }
+
+  public static HoodieTimeline toTimeline(TimelineDTO dto, HoodieTableMetaClient metaClient) {
+    InstantGenerator instantGenerator = metaClient.getInstantGenerator();
+    TimelineFactory factory = metaClient.getTimelineLayout().getTimelineFactory();
+    // TODO: For Now, we will assume, only active-timeline will be transferred.
+    return factory.createDefaultTimeline(dto.instants.stream().map(d -> InstantDTO.toInstant(d, instantGenerator)),
+        metaClient.getActiveTimeline());
+  }
+}

hudi-common/src/main/java/org/apache/hudi/common/table/view/RemoteHoodieTableFileSystemView.java

@@ -68,6 +68,7 @@ public class RemoteHoodieTableFileSystemView implements SyncableFileSystemView,
 
   private static final String SCHEME = "http";
   private static final String BASE_URL = "/v1/hoodie/view";
+  private static final String BASE_URL_V2 = "/v2/hoodie/view";
   public static final String LATEST_PARTITION_SLICES_URL = String.format("%s/%s", BASE_URL, "slices/partition/latest/");
   public static final String LATEST_PARTITION_SLICES_INFLIGHT_URL = String.format("%s/%s", BASE_URL, "slices/partition/latest/inflight/");
   public static final String LATEST_PARTITION_SLICES_STATELESS_URL = String.format("%s/%s", BASE_URL, "slices/partition/latest/stateless/");
@@ -103,7 +104,10 @@ public class RemoteHoodieTableFileSystemView implements SyncableFileSystemView,
   public static final String LAST_INSTANT_URL = String.format("%s/%s", BASE_URL, "timeline/instant/last");
   public static final String LAST_INSTANTS_URL = String.format("%s/%s", BASE_URL, "timeline/instants/last");
 
+  public static final String INSTANT_DETAILS_URL = String.format("%s/%s", BASE_URL_V2, "timeline/instant");
+
   public static final String TIMELINE_URL = String.format("%s/%s", BASE_URL, "timeline/instants/all");
+  public static final String TIMELINE_V2_URL = String.format("%s/%s", BASE_URL_V2, "timeline/instants/all");
 
   // POST Requests
   public static final String REFRESH_TABLE_URL = String.format("%s/%s", BASE_URL, "refresh/");
@@ -114,6 +118,8 @@ public class RemoteHoodieTableFileSystemView implements SyncableFileSystemView,
   public static final String PARTITIONS_PARAM = "partitions";
   public static final String BASEPATH_PARAM = "basepath";
   public static final String INSTANT_PARAM = "instant";
+  public static final String INSTANT_ACTION_PARAM = "instantaction";
+  public static final String INSTANT_STATE_PARAM = "instantstate";
   public static final String MAX_INSTANT_PARAM = "maxinstant";
   public static final String MIN_INSTANT_PARAM = "mininstant";
   public static final String INSTANTS_PARAM = "instants";

hudi-timeline-service/pom.xml

@@ -122,6 +122,12 @@
       <version>${javalin.version}</version>
     </dependency>
 
+    <dependency>
+      <groupId>org.thymeleaf</groupId>
+      <artifactId>thymeleaf</artifactId>
+      <version>${thymeleaf.version}</version>
+    </dependency>
+
     <dependency>
       <groupId>com.beust</groupId>
       <artifactId>jcommander</artifactId>

hudi-timeline-service/src/main/java/org/apache/hudi/timeline/service/RequestHandler.java

@@ -173,6 +173,18 @@ private static String getMinInstantParam(Context ctx) {
     return ctx.queryParamAsClass(RemoteHoodieTableFileSystemView.MIN_INSTANT_PARAM, String.class).getOrDefault("");
   }
 
+  private static String getInstantParam(Context ctx) {
+    return ctx.queryParamAsClass(RemoteHoodieTableFileSystemView.INSTANT_PARAM, String.class).getOrDefault("");
+  }
+
+  private static String getInstantActionParam(Context ctx) {
+    return ctx.queryParamAsClass(RemoteHoodieTableFileSystemView.INSTANT_ACTION_PARAM, String.class).getOrDefault("");
+  }
+
+  private static String getInstantStateParam(Context ctx) {
+    return ctx.queryParamAsClass(RemoteHoodieTableFileSystemView.INSTANT_STATE_PARAM, String.class).getOrDefault("");
+  }
+
   private static String getMarkerDirParam(Context ctx) {
     return ctx.queryParamAsClass(MarkerOperation.MARKER_DIR_PATH_PARAM, String.class).getOrDefault("");
   }
@@ -246,6 +258,19 @@ private void registerTimelineAPI() {
       TimelineDTO dto = instantHandler.getTimeline(getBasePathParam(ctx));
       writeValueAsString(ctx, dto);
     }, false));
+
+    app.get(RemoteHoodieTableFileSystemView.TIMELINE_V2_URL, new ViewHandler(ctx -> {
+      metricsRegistry.add("TIMELINE_V2", 1);
+      org.apache.hudi.common.table.timeline.dto.v2.TimelineDTO dto = instantHandler.getTimelineV2(getBasePathParam(ctx));
+      writeValueAsString(ctx, dto);
+    }, false));
+
+    app.get(RemoteHoodieTableFileSystemView.INSTANT_DETAILS_URL, new ViewHandler(ctx -> {
+      metricsRegistry.add("INSTANT_DETAILS", 1);
+      Object instantDetailsObj = instantHandler.getInstantDetails(getBasePathParam(ctx),
+          getInstantParam(ctx), getInstantActionParam(ctx), getInstantStateParam(ctx));
+      writeValueAsString(ctx, instantDetailsObj);
+    }, false));
   }
 
   /**

hudi-timeline-service/src/main/java/org/apache/hudi/timeline/service/TimelineService.java

@@ -32,6 +32,7 @@
 import com.beust.jcommander.Parameter;
 import io.javalin.Javalin;
 import io.javalin.core.util.JavalinBindException;
+import org.apache.hudi.timeline.service.ui.UiHandler;
 import org.eclipse.jetty.server.Server;
 import org.eclipse.jetty.util.thread.QueuedThreadPool;
 import org.eclipse.jetty.util.thread.ScheduledExecutorScheduler;
@@ -57,6 +58,7 @@ public class TimelineService {
   private transient Javalin app = null;
   private transient FileSystemViewManager fsViewsManager;
   private transient RequestHandler requestHandler;
+  private transient UiHandler uiHandler;
 
   public int getServerPort() {
     return serverPort;
@@ -387,8 +389,20 @@ private void createApp() {
 
     requestHandler = new RequestHandler(
         app, storageConf, timelineServerConf, context, fsViewsManager);
+    uiHandler = new UiHandler(app);
     app.get("/", ctx -> ctx.result("Hello Hudi"));
     requestHandler.register();
+    uiHandler.register();
+    // API endpoint for returning timeline events dynamically
+    app.get("/api/timeline", ctx -> {
+      // Return some dynamic event data
+      String timelineData = "["
+          + "{\"id\": 1, \"content\": \"Event 1\", \"start\": \"2025-04-01\"},"
+          + "{\"id\": 2, \"content\": \"Event 2\", \"start\": \"2025-04-02\"},"
+          + "{\"id\": 3, \"content\": \"Event 3\", \"start\": \"2025-04-03\"}"
+          + "]";
+      ctx.result(timelineData).contentType("application/json");
+    });
   }
 
   public void run() throws IOException {

hudi-timeline-service/src/main/java/org/apache/hudi/timeline/service/handlers/TimelineHandler.java

@@ -18,8 +18,12 @@
 
 package org.apache.hudi.timeline.service.handlers;
 
+import java.io.IOException;
+import org.apache.hudi.common.table.timeline.HoodieInstant;
+import org.apache.hudi.common.table.timeline.HoodieTimeline;
 import org.apache.hudi.common.table.timeline.dto.InstantDTO;
 import org.apache.hudi.common.table.timeline.dto.TimelineDTO;
+import org.apache.hudi.common.table.timeline.versioning.v1.InstantComparatorV1;
 import org.apache.hudi.common.table.view.FileSystemViewManager;
 import org.apache.hudi.storage.StorageConfiguration;
 import org.apache.hudi.timeline.service.TimelineService;
@@ -46,4 +50,30 @@ public List<InstantDTO> getLastInstant(String basePath) {
   public TimelineDTO getTimeline(String basePath) {
     return TimelineDTO.fromTimeline(viewManager.getFileSystemView(basePath).getTimeline());
   }
+
+  public org.apache.hudi.common.table.timeline.dto.v2.TimelineDTO getTimelineV2(String basePath) {
+    return org.apache.hudi.common.table.timeline.dto.v2.TimelineDTO.fromTimeline(viewManager.getFileSystemView(basePath).getTimeline());
+  }
+
+  public Object getInstantDetails(String basePath, String requestedTime, String action, String state)
+      throws IOException {
+    HoodieTimeline hoodieTimeline = viewManager.getFileSystemView(basePath).getTimeline();
+    try {
+      HoodieInstant requestedInstant = new HoodieInstant(
+          HoodieInstant.State.valueOf(state), action, requestedTime,
+          InstantComparatorV1.REQUESTED_TIME_BASED_COMPARATOR);
+
+      switch (requestedInstant.getAction()) {
+        case HoodieTimeline.COMMIT_ACTION:
+        case HoodieTimeline.DELTA_COMMIT_ACTION:
+          return hoodieTimeline.readCommitMetadata(requestedInstant);
+        default:
+          // TODO: implement other actions
+          return null;
+      }
+    } catch (Exception e) {
+      // Input parameters might be invalid
+      return null;
+    }
+  }
 }

hudi-timeline-service/src/main/java/org/apache/hudi/timeline/service/ui/TimelineView.java

@@ -0,0 +1,33 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.hudi.timeline.service.ui;
+
+import io.javalin.http.Handler;
+import java.util.HashMap;
+import java.util.Map;
+
+public class TimelineView {
+
+  public static Handler serveTimelineView = ctx -> {
+    Map<String, Object> model = new HashMap<>();
+    model.put("title", "Vis Timeline Example/Demo");
+    ctx.render("/templates/timeline.html", model);
+  };
+
+}

hudi-timeline-service/src/main/java/org/apache/hudi/timeline/service/ui/UiHandler.java

@@ -0,0 +1,37 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.hudi.timeline.service.ui;
+
+import io.javalin.Javalin;
+
+/**
+ * Main User Interface (UI) Handler class that is responsible for rendering all UI pages.
+ */
+public class UiHandler {
+
+  private final Javalin app;
+
+  public UiHandler(Javalin app) {
+    this.app = app;
+  }
+
+  public void register() {
+    app.get("/timeline", TimelineView.serveTimelineView);
+  }
+}