steveloughran commented on a change in pull request #2069: URL: https://github.com/apache/hadoop/pull/2069#discussion_r474658532
########## File path: hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/statistics/IOStatisticsLogging.java ########## @@ -0,0 +1,182 @@ +/* + * 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.hadoop.fs.statistics; + +import javax.annotation.Nullable; +import java.util.Map; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import org.apache.hadoop.classification.InterfaceAudience; +import org.apache.hadoop.classification.InterfaceStability; +import org.apache.hadoop.fs.statistics.impl.IOStatisticsBinding; + +import static org.apache.hadoop.fs.statistics.IOStatisticsSupport.retrieveIOStatistics; + +/** + * Utility operations convert IO Statistics sources/instances + * to strings, especially for robustly logging. + */ +@InterfaceAudience.Public +@InterfaceStability.Unstable +public final class IOStatisticsLogging { + + private static final Logger LOG = + LoggerFactory.getLogger(IOStatisticsLogging.class); + + private IOStatisticsLogging() { + } + + /** + * Extract the statistics from a source object -or "" + * if it is not a source of statistics + * <p> + * Exceptions are caught and downgraded to debug logging. + * @param source source of statistics. + * @return a string for logging. + */ + public static String ioStatisticsSourceToString(@Nullable Object source) { + try { + return ioStatisticsToString(retrieveIOStatistics(source)); + } catch (RuntimeException e) { + LOG.debug("Ignoring", e); + return ""; + } + } + + /** + * Convert IOStatistics to a string form. + * @param statistics A statistics instance. + * @return string value or the empty string if null + */ + public static String ioStatisticsToString( + @Nullable final IOStatistics statistics) { + if (statistics != null) { + StringBuilder sb = new StringBuilder(); + mapToString(sb, "counters", statistics.counters()); + mapToString(sb, "gauges", statistics.gauges()); + mapToString(sb, "minimums", statistics.minimums()); + mapToString(sb, "maximums", statistics.maximums()); + mapToString(sb, "means", statistics.meanStatistics()); + + return sb.toString(); + } else { + return ""; + } + } + + private static <E> void mapToString(StringBuilder sb, + final String type, + final Map<String, E> map) { + int count = 0; + sb.append(type); + sb.append("=("); + for (Map.Entry<String, E> entry : map.entrySet()) { + if (count > 0) { + sb.append(' '); + } + count++; + sb.append(IOStatisticsBinding.entryToString( + entry.getKey(), entry.getValue())); + } Review comment: yeah, you are probably right. Will fix ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to 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 --------------------------------------------------------------------- To unsubscribe, e-mail: common-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: common-issues-h...@hadoop.apache.org
