steveloughran commented on code in PR #1187: URL: https://github.com/apache/parquet-mr/pull/1187#discussion_r1450854297
########## parquet-hadoop/src/main/java/org/apache/parquet/hadoop/ParquetMetricsCallback.java: ########## @@ -0,0 +1,34 @@ +/* + * 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.parquet.hadoop; + +/** + * a simple interface to pass basic metric values by name to any implementation. Typically an + * implementation of this interface will serve as a bridge to pass metric values on + * to the metrics system of a distributed engine (hadoop, spark, etc). + */ +public interface ParquetMetricsCallback { Review Comment: +1 I should revisit state of the art there, and make sure that hadoop duration timers are good at -ve clock changes. [past commentary on 2015 CPUs](jhttps://steveloughran.blogspot.com/2015/09/time-on-multi-core-multi-socket-servers.html) maybe something like some soft referenced "source of time" per thread which is both (systime, nanotime) and when querying it if current nanotime is "close enough" to previous nanotime, just apply nanotime diff to systime; update systime fields. So it'd be "approximate per cpu core/socket", enough for metrics where things happen in millis -- 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. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
