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Jakob Homan commented on HDFS-1353: ----------------------------------- bq. In BlockTokenIdentifier constructor, should we check for non-zero blockId? Earlier we checked for non-null blockIds array. The blockID is a random number, so it might be 0, so we don't need to check that. Thanks. > Remove most of getBlockLocation optimization > -------------------------------------------- > > Key: HDFS-1353 > URL: https://issues.apache.org/jira/browse/HDFS-1353 > Project: Hadoop HDFS > Issue Type: Improvement > Components: name-node > Affects Versions: 0.21.0 > Reporter: Jakob Homan > Assignee: Jakob Homan > Fix For: 0.21.1, 0.22.0 > > Attachments: Benchmarking results.xlsx, HDFS-1353-y20.patch, > HDFS-1353.patch > > > <This description is not valid. See comment.> > HDFS-1081 optimized the number of block access tokens (BATs) created in a > single call to getBlockLocations, as this is an expensive operation. > However, that JIRA put off another optimization which was then made possible, > which is to just send a single block access token across the wire (and > maintain a single BAT on the client side). This JIRA is for implementing > that optimization. Since a single BAT is generated for all the blocks, we > just write that single BAT to the wire, rather than writing n BATs for n > blocks, as is currently done. This turns out to be a useful optimization for > files with very large numbers of blocks, as the new lone BAT is much larger > than was a BAT previously. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.