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Andrew Wang commented on HDFS-7345: ----------------------------------- I filed LEGAL-211, hopefully the legal team can provide some guidance on this matter. > Local Reconstruction Codes (LRC) > -------------------------------- > > Key: HDFS-7345 > URL: https://issues.apache.org/jira/browse/HDFS-7345 > Project: Hadoop HDFS > Issue Type: Sub-task > Reporter: Kai Zheng > Assignee: Kai Zheng > > HDFS-7285 proposes to support Erasure Coding inside HDFS, supports multiple > Erasure Coding codecs via pluggable framework and implements Reed Solomon > code by default. This is to support a more advanced coding mechanism, Local > Reconstruction Codes (LRC). As discussed in the paper > (https://www.usenix.org/system/files/conference/atc12/atc12-final181_0.pdf), > LRC reduces the number of erasure coding fragments that need to be read when > reconstructing data fragments that are offline, while still keeping the > storage overhead low. The important benefits of LRC are that it reduces the > bandwidth and I/Os required for repair reads over prior codes, while still > allowing a significant reduction in storage overhead. Intel ISA library also > supports LRC in its update and can also be leveraged. The implementation > would also consider how to distribute the calculating of local and global > parity blocks to other relevant DataNodes. -- This message was sent by Atlassian JIRA (v6.3.4#6332)