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Hudson commented on HDFS-12191: ------------------------------- SUCCESS: Integrated in Jenkins build Hadoop-trunk-Commit #12267 (See [https://builds.apache.org/job/Hadoop-trunk-Commit/12267/]) HDFS-12191. Provide option to not capture the accessTime change of a (yzhang: rev cf93d60d3f032000e5b78a08d320793d78799f3d) * (edit) hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirAttrOp.java * (edit) hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFSDirAttrOp.java * (edit) hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/snapshot/TestSnapshotDiffReport.java * (edit) hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSEditLogLoader.java * (edit) hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/snapshot/SnapshotManager.java * (edit) hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/INode.java * (edit) hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSConfigKeys.java * (edit) hadoop-hdfs-project/hadoop-hdfs/src/main/resources/hdfs-default.xml > Provide option to not capture the accessTime change of a file to snapshot if > no other modification has been done to this file > ----------------------------------------------------------------------------------------------------------------------------- > > Key: HDFS-12191 > URL: https://issues.apache.org/jira/browse/HDFS-12191 > Project: Hadoop HDFS > Issue Type: Bug > Components: hdfs, namenode > Affects Versions: 3.0.0-beta1 > Reporter: Yongjun Zhang > Assignee: Yongjun Zhang > Attachments: HDFS-12191.001.patch, HDFS-12191.002.patch, > HDFS-12191.003.patch, HDFS-12191.004.patch, HDFS-12191.005.patch > > > Currently, if the accessTime of a file changed before a snapshot is taken, > this accessTime will be captured in the snapshot, even if there is no other > modifications made to this file. > Because of this, when we calculate snapshotDiff, more work need to be done > for this file, e,g,, metadataEquals method will be called, even if there is > no modification is made (thus not recorded to snapshotDiff). This can cause > snapshotDiff to slow down quite a lot when there are a lot of files to be > examined. > This jira is to provide an option to skip capturing accessTime only change to > snapshot. Thus snapshotDiff can be done faster. > When accessTime of a file changed, if there is other modification to the > file, the access time will still be captured in snapshot. > Sometimes we want accessTime be captured to snapshot, such that when > restoring from the snapshot, we know the accessTime of this snapshot. So this > new feature is optional, and is controlled by a config property. > Worth to mention is, how accurately the acessTime is captured is dependent on > the following config that has default value of 1 hour, which means new access > within an hour of previous access will not be captured. > {code} > public static final String DFS_NAMENODE_ACCESSTIME_PRECISION_KEY = > > HdfsClientConfigKeys.DeprecatedKeys.DFS_NAMENODE_ACCESSTIME_PRECISION_KEY; > public static final long DFS_NAMENODE_ACCESSTIME_PRECISION_DEFAULT = > 3600000; > {code} > . -- This message was sent by Atlassian JIRA (v6.4.14#64029) --------------------------------------------------------------------- To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org