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Jing Zhao updated HDFS-5285: ---------------------------- Attachment: HDFS-5285.003.patch Thanks for the comments Vinay! Update the patch to address your comments. bq. Better to add an error message to these checks I have not changed this part in the new patch yet. Currently I just temporarily use Preconditions check to verify the under-construction file and some of them can be removed in the future I guess. We can revisit this later. > Flatten INodeFile hierarchy: Add UnderContruction Feature > --------------------------------------------------------- > > Key: HDFS-5285 > URL: https://issues.apache.org/jira/browse/HDFS-5285 > Project: Hadoop HDFS > Issue Type: Sub-task > Components: namenode > Reporter: Tsz Wo (Nicholas), SZE > Assignee: Jing Zhao > Attachments: HDFS-5285.001.patch, HDFS-5285.002.patch, > HDFS-5285.003.patch, h5285_20131001.patch, h5285_20131002.patch, > h5285_20131118.patch > > > For files, there are INodeFile, INodeFileUnderConstruction, > INodeFileWithSnapshot and INodeFileUnderConstructionWithSnapshot for > representing whether a file is under construction or whether it is in some > snapshot. The following are two major problems of the current approach: > - Java class does not support multiple inheritances so that > INodeFileUnderConstructionWithSnapshot cannot extend both > INodeFileUnderConstruction and INodeFileWithSnapshot. > - The number of classes is exponential to the number of features. Currently, > there are only two features, UnderConstruction and WithSnapshot. The number > of classes is 2^2 = 4. It is hard to add one more feature since the number > of classes will become 2^3 = 8. > As a first step, we implement an Under-Construction feature to replace > INodeFileUnderConstruction and INodeFileUnderConstructionWithSnapshot in this > jira. -- This message was sent by Atlassian JIRA (v6.1#6144)