jojochuang commented on a change in pull request #3148: URL: https://github.com/apache/hadoop/pull/3148#discussion_r659593248
########## File path: hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNode.java ########## @@ -2272,19 +2274,11 @@ public int getActiveTransferThreadCount() { void incrDatanodeNetworkErrors(String host) { metrics.incrDatanodeNetworkErrors(); - /* - * Synchronizing on the whole cache is a big hammer, but since it's only - * accumulating errors, it should be ok. If this is ever expanded to include - * non-error stats, then finer-grained concurrency should be applied. - */ - synchronized (datanodeNetworkCounts) { - try { - final Map<String, Long> curCount = datanodeNetworkCounts.get(host); - curCount.put("networkErrors", curCount.get("networkErrors") + 1L); - datanodeNetworkCounts.put(host, curCount); - } catch (ExecutionException e) { - LOG.warn("failed to increment network error counts for host: {}", host); - } + try { + datanodeNetworkCounts.get(host).compute(NETWORK_ERRORS, + (key, errors) -> errors == null ? null : errors + 1L); Review comment: not familiar with ConcurrentHashMap.compute() but wouldn't this make errors null always? -- 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: common-issues-unsubscr...@hadoop.apache.org 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