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Lei (Eddy) Xu commented on HDFS-11296: -------------------------------------- Hi, [~manojg] Thanks for working on this. I have a few questions regarding to this patch. There were a few efforts to replace wall time with {{monotonicNow()}} in the past, for example, HDFS-6841 and HDFS-6453. In general, different nodes can not guarantee time are synchronized, i.e., between clients, NameNode and DataNodes. Btw, IIUC, the expiration time set by client is the delta time instead of absolute time? > Maintenance state expiry should be an epoch time and not jvm monotonic > ---------------------------------------------------------------------- > > Key: HDFS-11296 > URL: https://issues.apache.org/jira/browse/HDFS-11296 > Project: Hadoop HDFS > Issue Type: Sub-task > Affects Versions: 3.0.0-alpha1 > Reporter: Manoj Govindassamy > Assignee: Manoj Govindassamy > Attachments: HDFS-11296.01.patch > > > Currently it is possible to configure an expiry time in milliseconds for a > DataNode in maintenance state. As per the design, the expiry attribute is an > absolute time, beyond which NameNode starts to stop the ongoing maintenance > operation for that DataNode. Internally in the code, this expiry time is read > and checked against {{Time.monotonicNow()}} making the expiry based on more > of JVM's runtime, which is very difficult to configure for any external user. > The goal is to make the expiry time an absolute epoch time, so that its easy > to configure for external users. > {noformat} > { > "hostName": <host>, > "port": <port>, > "adminState": "IN_MAINTENANCE", > "maintenanceExpireTimeInMS": <time in millis> > } > {noformat} > DatanodeInfo.java > {noformat} > public static boolean maintenanceNotExpired(long maintenanceExpireTimeInMS) > { > return Time.monotonicNow() < maintenanceExpireTimeInMS; > } > {noformat} -- 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