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jack liuquan commented on HADOOP-11828: --------------------------------------- Hi Kai, * In raw erasure coder level, you can set the {{ALLOW_CHANGE_INPUTS}} coder option to ensure the input buffers are not changed during encoding/decoding. Thus in HH coder level, you don't need to clone the input buffers thus avoids data copy. When I tested, I found that after running encode() of RS, non-direct buffer input's position will move to end. but direct buffer input's position will not move. Is that be OK? If I don't clone the input buffers in HH coder level, I will deal with non-direct buffer input and move input postion to the begin after I call encode() of RS. > Implement the Hitchhiker erasure coding algorithm > ------------------------------------------------- > > Key: HADOOP-11828 > URL: https://issues.apache.org/jira/browse/HADOOP-11828 > Project: Hadoop Common > Issue Type: Sub-task > Reporter: Zhe Zhang > Assignee: jack liuquan > Attachments: 7715-hitchhikerXOR-v2-testcode.patch, > 7715-hitchhikerXOR-v2.patch, HADOOP-11828-hitchhikerXOR-V3.patch, > HADOOP-11828-hitchhikerXOR-V4.patch, HADOOP-11828-hitchhikerXOR-V5.patch, > HDFS-7715-hhxor-decoder.patch, HDFS-7715-hhxor-encoder.patch > > > [Hitchhiker | > http://www.eecs.berkeley.edu/~nihar/publications/Hitchhiker_SIGCOMM14.pdf] is > a new erasure coding algorithm developed as a research project at UC > Berkeley. It has been shown to reduce network traffic and disk I/O by 25%-45% > during data reconstruction while retaining the same storage capacity and > failure tolerance capability as RS codes. This JIRA aims to introduce > Hitchhiker to the HDFS-EC framework, as one of the pluggable codec algorithms. > The existing implementation is based on HDFS-RAID. -- This message was sent by Atlassian JIRA (v6.3.4#6332)