Optimize number of block access tokens returned by getBlockLocations --------------------------------------------------------------------
Key: HDFS-1353 URL: https://issues.apache.org/jira/browse/HDFS-1353 Project: Hadoop HDFS Issue Type: Improvement Components: name-node Affects Versions: 0.22.0 Reporter: Jakob Homan Assignee: Jakob Homan Fix For: 0.22.0 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.