[ https://issues.apache.org/jira/browse/HADOOP-12444?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Steve Loughran updated HADOOP-12444: ------------------------------------ Status: Patch Available (was: Open) > Consider implementing lazy seek in S3AInputStream > ------------------------------------------------- > > Key: HADOOP-12444 > URL: https://issues.apache.org/jira/browse/HADOOP-12444 > Project: Hadoop Common > Issue Type: Sub-task > Components: fs/s3 > Affects Versions: 2.7.1 > Reporter: Rajesh Balamohan > Assignee: Rajesh Balamohan > Attachments: HADOOP-12444-004.patch, HADOOP-12444.1.patch, > HADOOP-12444.2.patch, HADOOP-12444.3.patch, HADOOP-12444.WIP.patch, > hadoop-aws-test-reports.tar.gz > > > - Currently, "read(long position, byte[] buffer, int offset, int length)" is > not implemented in S3AInputStream (unlike DFSInputStream). So, > "readFully(long position, byte[] buffer, int offset, int length)" in > S3AInputStream goes through the default implementation of seek(), read(), > seek() in FSInputStream. > - However, seek() in S3AInputStream involves re-opening of connection to S3 > everytime > (https://github.com/apache/hadoop/blob/trunk/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/S3AInputStream.java#L115). > > - It would be good to consider having a lazy seek implementation to reduce > connection overheads to S3. (e.g Presto implements lazy seek. > https://github.com/facebook/presto/blob/master/presto-hive/src/main/java/com/facebook/presto/hive/PrestoS3FileSystem.java#L623) -- This message was sent by Atlassian JIRA (v6.3.4#6332)