sjwiesman commented on a change in pull request #6814: [FLINK-10423][rocksdb][metrics] rocksdb native metrics monitor URL: https://github.com/apache/flink/pull/6814#discussion_r224855111
########## File path: flink-state-backends/flink-statebackend-rocksdb/src/main/java/org/apache/flink/contrib/streaming/state/RocksDBNativeMetricMonitor.java ########## @@ -0,0 +1,154 @@ +/* + * 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.flink.contrib.streaming.state; + +import org.apache.flink.annotation.Internal; +import org.apache.flink.core.fs.CloseableRegistry; +import org.apache.flink.metrics.Gauge; +import org.apache.flink.metrics.MetricGroup; +import org.apache.flink.metrics.View; +import org.apache.flink.util.FlinkRuntimeException; +import org.apache.flink.util.IOUtils; +import org.apache.flink.util.ResourceGuard; + +import org.rocksdb.ColumnFamilyHandle; +import org.rocksdb.RocksDB; +import org.rocksdb.RocksDBException; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import javax.annotation.Nonnull; + +import java.io.Closeable; +import java.io.IOException; + +/** + * A monitor which pull {{@link RocksDB}} native metrics + * and forwards them to Flink's metric group. All metrics are + * unsigned longs and are reported at the column family level. + */ +@Internal +public class RocksDBNativeMetricMonitor implements Closeable { + + private final CloseableRegistry registeredGauges; + + private final RocksDB db; + + private final ResourceGuard.Lease lease; + + private final RocksDBNativeMetricOptions options; + + private final MetricGroup metricGroup; + + RocksDBNativeMetricMonitor( + @Nonnull RocksDB db, + @Nonnull ResourceGuard guard, + @Nonnull RocksDBNativeMetricOptions options, + @Nonnull MetricGroup metricGroup + ) throws IOException { + this.db = db; + this.lease = guard.acquireResource(); + this.options = options; + this.metricGroup = metricGroup; + + this.registeredGauges = new CloseableRegistry(); + } + + /** + * Register gauges to pull native metrics for the column family. + * @param columnFamilyName group name for the new gauges + * @param handle native handle to the column family + */ + void registerColumnFamily(String columnFamilyName, ColumnFamilyHandle handle) { + try { + MetricGroup group = metricGroup.addGroup(columnFamilyName); + + for (String property : options.getProperties()) { + RocksDBNativeMetricView gauge = new RocksDBNativeMetricView( + property, + handle, + db + ); + + group.gauge(property, gauge); + registeredGauges.registerCloseable(gauge); + } + } catch (IOException e) { + throw new FlinkRuntimeException("Unable to register native metrics with RocksDB", e); + } + } + + @Override + public void close() { + IOUtils.closeQuietly(registeredGauges); + IOUtils.closeQuietly(lease); + } + + static class RocksDBNativeMetricView implements Gauge<String>, View, Closeable { + private static final Logger LOG = LoggerFactory.getLogger(RocksDBNativeMetricView.class); + + private final String property; + + private final ColumnFamilyHandle handle; + + private final RocksDB db; + + private volatile boolean open; + + private long value; + + private RocksDBNativeMetricView( + @Nonnull String property, + @Nonnull ColumnFamilyHandle handle, + @Nonnull RocksDB db + ) { + this.property = property; + this.handle = handle; + this.db = db; + this.open = true; + } + + @Override + public String getValue() { + return Long.toUnsignedString(value); + } + + @Override + public void update() { + if (open) { Review comment: I create a `MetricGroup` per column family so keeping references to each of those would be simple. If we just make `view` closeable, and each gauge keeps a lease for its entire lifetime, then we can close all the metrics groups in dispose which will unregister all the gauges and close the leases. Thoughts? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services
