[Offload] Add offload performance metrics for tiered storage.

managed-ledger/src/main/java/org/apache/bookkeeper/mledger/LedgerOffloader.java

@@ -213,6 +213,13 @@ default CompletableFuture<Void> deleteOffloaded(UUID uid,
      */
     OffloadPoliciesImpl getOffloadPolicies();
 
+    /**
+     * Get offload stats.
+     *
+     * @return the ledger offloader MBean
+     */
+    LedgerOffloaderMXBean getStats();
+
     /**
      * Close the resources if necessary
      */

managed-ledger/src/main/java/org/apache/bookkeeper/mledger/LedgerOffloaderMXBean.java

@@ -0,0 +1,137 @@
+/**
+ * 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.bookkeeper.mledger;
+
+import java.util.Map;
+import java.util.concurrent.TimeUnit;
+
+import org.apache.bookkeeper.common.annotation.InterfaceAudience;
+import org.apache.bookkeeper.common.annotation.InterfaceStability;
+import org.apache.bookkeeper.mledger.util.StatsBuckets;
+import org.apache.pulsar.common.stats.Rate;
+
+
+/**
+ * Management Bean for a {@link LedgerOffloader}.
+ */
+@InterfaceAudience.LimitedPrivate
+@InterfaceStability.Stable
+public interface LedgerOffloaderMXBean {
+
+    /**
+     * The ledger offloader name.
+     *
+     * @return ledger offloader name.
+     */
+    String getDriverName();
+
+
+    /**
+     * Refresh offloader stats.
+     *
+     */
+    void refreshStats(long period, TimeUnit unit);
+
+
+
+    /**
+     * Record the offload total time.
+     *
+     * @return offload time per topic.
+     */
+    Map<String, Rate> getOffloadTimes();
+
+    /**
+     * Record the offload error count.
+     *
+     * @return offload errors per topic.
+     */
+    Map<String, Rate> getOffloadErrors();
+
+    /**
+     * Record the offload rate to storage.
+     *
+     * @return offload rate per topic.
+     */
+    Map<String, Rate> getOffloadRates();
+
+
+    /**
+     * Record the read ledger latency.
+     *
+     * @return read ledger latency per topic.
+     */
+    Map<String, StatsBuckets> getReadLedgerLatencyBuckets();
+
+    /**
+     * Record the write latency to tiered storage.
+     *
+     * @return write to storage latency per topic.
+     */
+    Map<String, StatsBuckets> getWriteToStorageLatencyBuckets();
+
+    /**
+     * Record the write to storage error count.
+     *
+     * @return write to storage errors per topic.
+     */
+    Map<String, Rate> getWriteToStorageErrors();
+
+    /**
+     * Record read offload index latency.
+     *
+     * @return read offload index latency per topic.
+     */
+    Map<String, StatsBuckets> getReadOffloadIndexLatencyBuckets();
+
+    /**
+     * Record read offload data latency.
+     *
+     * @return read offload data latency per topic.
+     */
+    Map<String, StatsBuckets> getReadOffloadDataLatencyBuckets();
+
+    /**
+     * Record read offload method rate.
+     *
+     * @return read offload data rate.
+     */
+    Map<String, Rate> getReadOffloadRates();
+
+    /**
+     * Record read offload error count.
+     *
+     * @return read offload data errors.
+     */
+    Map<String, Rate> getReadOffloadErrors();
+
+    /**
+     * Record streaming read offload method rate.
+     *
+     * @return streaming write to storage rate per topic.
+     */
+    Map<String, Rate> getStreamingWriteToStorageRates();
+
+    /**
+     * Record streaming read offload error count.
+     *
+     * @return streaming write to storage errors per topic.
+     */
+    Map<String, Rate> getStreamingWriteToStorageErrors();
+}