diff --git a/service-t/src/com/android/metrics/NetworkStatsMetricsLogger.java b/service-t/src/com/android/metrics/NetworkStatsMetricsLogger.java
new file mode 100644
index 0000000..2cf49ba
--- /dev/null
+++ b/service-t/src/com/android/metrics/NetworkStatsMetricsLogger.java
@@ -0,0 +1,125 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed 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 com.android.metrics;
+
+import static android.net.netstats.NetworkStatsDataMigrationUtils.PREFIX_UID;
+import static android.net.netstats.NetworkStatsDataMigrationUtils.PREFIX_UID_TAG;
+import static android.net.netstats.NetworkStatsDataMigrationUtils.PREFIX_XT;
+
+import static com.android.server.ConnectivityStatsLog.NETWORK_STATS_RECORDER_FILE_OPERATED;
+import static com.android.server.ConnectivityStatsLog.NETWORK_STATS_RECORDER_FILE_OPERATED__FAST_DATA_INPUT_STATE__FDIS_DISABLED;
+import static com.android.server.ConnectivityStatsLog.NETWORK_STATS_RECORDER_FILE_OPERATED__OPERATION_TYPE__ROT_READ;
+import static com.android.server.ConnectivityStatsLog.NETWORK_STATS_RECORDER_FILE_OPERATED__RECORDER_PREFIX__PREFIX_UID;
+import static com.android.server.ConnectivityStatsLog.NETWORK_STATS_RECORDER_FILE_OPERATED__RECORDER_PREFIX__PREFIX_UIDTAG;
+import static com.android.server.ConnectivityStatsLog.NETWORK_STATS_RECORDER_FILE_OPERATED__RECORDER_PREFIX__PREFIX_UNKNOWN;
+import static com.android.server.ConnectivityStatsLog.NETWORK_STATS_RECORDER_FILE_OPERATED__RECORDER_PREFIX__PREFIX_XT;
+
+import android.annotation.NonNull;
+import android.net.NetworkStatsCollection;
+import android.net.NetworkStatsHistory;
+
+import com.android.internal.annotations.VisibleForTesting;
+import com.android.server.ConnectivityStatsLog;
+
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * Helper class to log NetworkStats related metrics.
+ *
+ * This class does not provide thread-safe.
+ */
+public class NetworkStatsMetricsLogger {
+    final Dependencies mDeps;
+    int mReadIndex = 1;
+
+    /** Dependency class */
+    @VisibleForTesting
+    public static class Dependencies {
+        /**
+         * Writes a NETWORK_STATS_RECORDER_FILE_OPERATION_REPORTED event to ConnectivityStatsLog.
+         */
+        public void writeRecorderFileReadingStats(int recorderType, int readIndex,
+                                                  int readLatencyMillis,
+                                                  int fileCount, int totalFileSize,
+                                                  int keys, int uids, int totalHistorySize) {
+            ConnectivityStatsLog.write(NETWORK_STATS_RECORDER_FILE_OPERATED,
+                    NETWORK_STATS_RECORDER_FILE_OPERATED__OPERATION_TYPE__ROT_READ,
+                    recorderType,
+                    readIndex,
+                    readLatencyMillis,
+                    fileCount,
+                    totalFileSize,
+                    keys,
+                    uids,
+                    totalHistorySize,
+                    NETWORK_STATS_RECORDER_FILE_OPERATED__FAST_DATA_INPUT_STATE__FDIS_DISABLED);
+        }
+    }
+
+    public NetworkStatsMetricsLogger() {
+        mDeps = new Dependencies();
+    }
+
+    @VisibleForTesting
+    public NetworkStatsMetricsLogger(Dependencies deps) {
+        mDeps = deps;
+    }
+
+    private static int prefixToRecorderType(@NonNull String prefix) {
+        switch (prefix) {
+            case PREFIX_XT:
+                return NETWORK_STATS_RECORDER_FILE_OPERATED__RECORDER_PREFIX__PREFIX_XT;
+            case PREFIX_UID:
+                return NETWORK_STATS_RECORDER_FILE_OPERATED__RECORDER_PREFIX__PREFIX_UID;
+            case PREFIX_UID_TAG:
+                return NETWORK_STATS_RECORDER_FILE_OPERATED__RECORDER_PREFIX__PREFIX_UIDTAG;
+            default:
+                return NETWORK_STATS_RECORDER_FILE_OPERATED__RECORDER_PREFIX__PREFIX_UNKNOWN;
+        }
+    }
+
+    /**
+     * Log statistics from the NetworkStatsRecorder file reading process into statsd.
+     */
+    public void logRecorderFileReading(@NonNull String prefix, int readLatencyMillis,
+                                              @NonNull NetworkStatsCollection collection) {
+        final Set<Integer> uids = new HashSet<>();
+        final Map<NetworkStatsCollection.Key, NetworkStatsHistory> entries =
+                collection.getEntries();
+
+        for (final NetworkStatsCollection.Key key : entries.keySet()) {
+            uids.add(key.uid);
+        }
+
+        int totalHistorySize = 0;
+        for (final NetworkStatsHistory history : entries.values()) {
+            totalHistorySize += history.size();
+        }
+
+        // TODO: Fill file characteristics.
+        mDeps.writeRecorderFileReadingStats(prefixToRecorderType(prefix),
+                mReadIndex++,
+                readLatencyMillis,
+                0 /* fileCount */,
+                0 /* totalFileSize */,
+                entries.size(),
+                uids.size(),
+                totalHistorySize);
+    }
+}
diff --git a/service-t/src/com/android/server/net/NetworkStatsRecorder.java b/service-t/src/com/android/server/net/NetworkStatsRecorder.java
index 5f9b65c..456a212 100644
--- a/service-t/src/com/android/server/net/NetworkStatsRecorder.java
+++ b/service-t/src/com/android/server/net/NetworkStatsRecorder.java
@@ -32,12 +32,14 @@
 import android.net.TrafficStats;
 import android.os.Binder;
 import android.os.DropBoxManager;
+import android.os.SystemClock;
 import android.service.NetworkStatsRecorderProto;
 import android.util.IndentingPrintWriter;
 import android.util.Log;
 import android.util.proto.ProtoOutputStream;
 
 import com.android.internal.util.FileRotator;
+import com.android.metrics.NetworkStatsMetricsLogger;
 import com.android.net.module.util.NetworkStatsUtils;
 
 import libcore.io.IoUtils;
@@ -90,6 +92,7 @@
     private final CombiningRewriter mPendingRewriter;
 
     private WeakReference<NetworkStatsCollection> mComplete;
+    private final NetworkStatsMetricsLogger mMetricsLogger = new NetworkStatsMetricsLogger();
 
     /**
      * Non-persisted recorder, with only one bucket. Used by {@link NetworkStatsObservers}.
@@ -182,8 +185,15 @@
         Objects.requireNonNull(mRotator, "missing FileRotator");
         NetworkStatsCollection res = mComplete != null ? mComplete.get() : null;
         if (res == null) {
+            final long readStart = SystemClock.elapsedRealtime();
             res = loadLocked(Long.MIN_VALUE, Long.MAX_VALUE);
             mComplete = new WeakReference<NetworkStatsCollection>(res);
+            final long readEnd = SystemClock.elapsedRealtime();
+            // For legacy recorders which are used for data integrity check, which
+            // have wipeOnError flag unset, skip reporting metrics.
+            if (mWipeOnError) {
+                mMetricsLogger.logRecorderFileReading(mCookie, (int) (readEnd - readStart), res);
+            }
         }
         return res;
     }
diff --git a/tests/unit/java/android/net/NetworkStatsRecorderTest.java b/tests/unit/java/android/net/NetworkStatsRecorderTest.java
index e8f853e..9ec9a79 100644
--- a/tests/unit/java/android/net/NetworkStatsRecorderTest.java
+++ b/tests/unit/java/android/net/NetworkStatsRecorderTest.java
@@ -16,8 +16,15 @@
 
 package com.android.server.net;
 
+import static android.net.NetworkStats.SET_DEFAULT;
+import static android.net.NetworkStats.SET_FOREGROUND;
+import static android.net.NetworkStats.TAG_NONE;
+import static android.net.netstats.NetworkStatsDataMigrationUtils.PREFIX_UID;
+import static android.net.netstats.NetworkStatsDataMigrationUtils.PREFIX_XT;
 import static android.text.format.DateUtils.HOUR_IN_MILLIS;
 
+import static com.android.server.ConnectivityStatsLog.NETWORK_STATS_RECORDER_FILE_OPERATED__RECORDER_PREFIX__PREFIX_UID;
+import static com.android.server.ConnectivityStatsLog.NETWORK_STATS_RECORDER_FILE_OPERATED__RECORDER_PREFIX__PREFIX_XT;
 import static com.android.testutils.DevSdkIgnoreRuleKt.SC_V2;
 
 import static org.mockito.Mockito.any;
@@ -29,12 +36,16 @@
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 
+import android.net.NetworkIdentity;
+import android.net.NetworkIdentitySet;
 import android.net.NetworkStats;
+import android.net.NetworkStatsCollection;
 import android.os.DropBoxManager;
 
 import androidx.test.filters.SmallTest;
 
 import com.android.internal.util.FileRotator;
+import com.android.metrics.NetworkStatsMetricsLogger;
 import com.android.testutils.DevSdkIgnoreRule;
 import com.android.testutils.DevSdkIgnoreRunner;
 
@@ -53,6 +64,8 @@
     private static final String TAG = NetworkStatsRecorderTest.class.getSimpleName();
 
     private static final String TEST_PREFIX = "test";
+    private static final int TEST_UID1 = 1234;
+    private static final int TEST_UID2 = 1235;
 
     @Mock private DropBoxManager mDropBox;
     @Mock private NetworkStats.NonMonotonicObserver mObserver;
@@ -86,4 +99,65 @@
         // Verify that the rotator won't delete files.
         verify(rotator, never()).deleteAll();
     }
+
+    @Test
+    public void testFileReadingMetrics_empty() {
+        final NetworkStatsCollection collection = new NetworkStatsCollection(30);
+        final NetworkStatsMetricsLogger.Dependencies deps =
+                mock(NetworkStatsMetricsLogger.Dependencies.class);
+        final NetworkStatsMetricsLogger logger = new NetworkStatsMetricsLogger(deps);
+        logger.logRecorderFileReading(PREFIX_XT, 888, collection);
+        verify(deps).writeRecorderFileReadingStats(
+                NETWORK_STATS_RECORDER_FILE_OPERATED__RECORDER_PREFIX__PREFIX_XT,
+                1 /* readIndex */,
+                888 /* readLatencyMillis */,
+                0 /* fileCount */,
+                0 /* totalFileSize */,
+                0 /* keys */,
+                0 /* uids */,
+                0 /* totalHistorySize */
+        );
+
+        // Write second time, verify the index increases.
+        logger.logRecorderFileReading(PREFIX_XT, 567, collection);
+        verify(deps).writeRecorderFileReadingStats(
+                NETWORK_STATS_RECORDER_FILE_OPERATED__RECORDER_PREFIX__PREFIX_XT,
+                2 /* readIndex */,
+                567 /* readLatencyMillis */,
+                0 /* fileCount */,
+                0 /* totalFileSize */,
+                0 /* keys */,
+                0 /* uids */,
+                0 /* totalHistorySize */
+        );
+    }
+
+    @Test
+    public void testFileReadingMetrics() {
+        final NetworkStatsCollection collection = new NetworkStatsCollection(30);
+        final NetworkStats.Entry entry = new NetworkStats.Entry();
+        final NetworkIdentitySet identSet = new NetworkIdentitySet();
+        identSet.add(new NetworkIdentity.Builder().build());
+        // Empty entries will be skipped, put some ints to make sure they can be recorded.
+        entry.rxBytes = 1;
+
+        collection.recordData(identSet, TEST_UID1, SET_DEFAULT, TAG_NONE, 0, 60, entry);
+        collection.recordData(identSet, TEST_UID2, SET_DEFAULT, TAG_NONE, 0, 60, entry);
+        collection.recordData(identSet, TEST_UID2, SET_FOREGROUND, TAG_NONE, 30, 60, entry);
+
+        final NetworkStatsMetricsLogger.Dependencies deps =
+                mock(NetworkStatsMetricsLogger.Dependencies.class);
+        final NetworkStatsMetricsLogger logger = new NetworkStatsMetricsLogger(deps);
+        logger.logRecorderFileReading(PREFIX_UID, 123, collection);
+        verify(deps).writeRecorderFileReadingStats(
+                NETWORK_STATS_RECORDER_FILE_OPERATED__RECORDER_PREFIX__PREFIX_UID,
+                1 /* readIndex */,
+                123 /* readLatencyMillis */,
+                0 /* fileCount */,
+                0 /* totalFileSize */,
+                3 /* keys */,
+                2 /* uids */,
+                5 /* totalHistorySize */
+        );
+    }
 }