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Haohui Mai commented on HDFS-6982: ---------------------------------- bq. The minimal change is a couple of lines to register TopMetrics with the hadoop metrics system. Can you please provide a patch which just includes this functionality? That way it can quickly be reviewed and committed. bq. The rolling window only provides light weight aggregation and this logic can also be in an external process as it was suggested in the second architecture in the design doc. If this is the case, maybe we can separate the rolling window in a separate jira. What do you think? > nntop: top-like tool for name node users > ----------------------------------------- > > Key: HDFS-6982 > URL: https://issues.apache.org/jira/browse/HDFS-6982 > Project: Hadoop HDFS > Issue Type: New Feature > Reporter: Maysam Yabandeh > Assignee: Maysam Yabandeh > Attachments: HDFS-6982.patch, HDFS-6982.v2.patch, nntop-design-v1.pdf > > > In this jira we motivate the need for nntop, a tool that, similarly to what > top does in Linux, gives the list of top users of the HDFS name node and > gives insight about which users are sending majority of each traffic type to > the name node. This information turns out to be the most critical when the > name node is under pressure and the HDFS admin needs to know which user is > hammering the name node and with what kind of requests. Here we present the > design of nntop which has been in production at Twitter in the past 10 > months. nntop proved to have low cpu overhead (< 2% in a cluster of 4K > nodes), low memory footprint (less than a few MB), and quite efficient for > the write path (only two hash lookup for updating a metric). -- This message was sent by Atlassian JIRA (v6.3.4#6332)