[ https://issues.apache.org/jira/browse/HDFS-8410?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15590805#comment-15590805 ]
SammiChen commented on HDFS-8410: --------------------------------- It costs about 2 milliseconds in my desktop to decode a strip group with 6 blocks, each block is 64k. This decoding time merely depends on how fast the CPU is. It's "Intel(R) Core(TM) i5-4460 CPU @ 3.20GHz" with 4 cores in my desktop, not the leading edge CPU model. Given that CPU is becoming more and more powerful, I think it is not safe to use millisecond granularity to record one time decoding time. We can choose between nanosecond or microsecond. I would prefer nanosecond for one reason. it can be directly get through {{System.nanoTime()}}. If microsecond is used, there is one extra division of 1000. That's not good from performance point of view. And a {{long}} number can host nanoseconds, representing hundreds of years. So there is not going to a overflow quickly. > Add computation time metrics to datanode for ECWorker > ----------------------------------------------------- > > Key: HDFS-8410 > URL: https://issues.apache.org/jira/browse/HDFS-8410 > Project: Hadoop HDFS > Issue Type: Sub-task > Reporter: Li Bo > Assignee: SammiChen > Attachments: HDFS-8410-001.patch, HDFS-8410-002.patch, > HDFS-8410-003.patch, HDFS-8410-004.patch > > > This is a sub task of HDFS-7674. It adds time metric for ec decode work. -- This message was sent by Atlassian JIRA (v6.3.4#6332) --------------------------------------------------------------------- To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org