[
https://issues.apache.org/jira/browse/HDFS-7348?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Zhe Zhang updated HDFS-7348:
----------------------------
Attachment: ECWorker.java
This is a very rough prototype I wrote *long time ago*. On {{DataNode}}, upon
receiving a codec command, it starts the {{ECWorker}} like this:
{code}
private void encodeBlock(ExtendedBlock block, BlockGroup bg) throws
IOException {
LinkedList<ExtendedBlock> blocks = new LinkedList<ExtendedBlock>();
LinkedList<DatanodeInfo> sources = new LinkedList<DatanodeInfo>();
for (LocatedBlock lb : bg.getLocatedBlocks()) {
blocks.add(new ExtendedBlock(block.getBlockPoolId(),
lb.getBlock().getLocalBlock()));
sources.add(lb.getLocations()[0]);
}
LOG.debug("encodeBlock " + block);
ECWorker ecWorker = new ECWorker(block.getLocalBlock(),
blocks.toArray(new ExtendedBlock[blocks.size()]),
sources.toArray(new DatanodeInfo[sources.size()]), this);
ecWorkerMap.put(block.getLocalBlock(), ecWorker);
new Daemon(ecWorker).start();
}
{code}
Just wanted to share it here in case it's of any help.
Basically, it mimics the existing {{DataTransfer}} in {{DataNode}} but pulls
data instead of pushing.
I'm not sure if we should follow this direction or create a block reader /
writer for this purpose. Let's brainstorm here first.
> Erasure Coding: perform stripping erasure decoding/recovery work given block
> reader and writer
> ----------------------------------------------------------------------------------------------
>
> Key: HDFS-7348
> URL: https://issues.apache.org/jira/browse/HDFS-7348
> Project: Hadoop HDFS
> Issue Type: Sub-task
> Components: datanode
> Reporter: Kai Zheng
> Assignee: Yi Liu
> Attachments: ECWorker.java
>
>
> This assumes the facilities like block reader and writer are ready,
> implements and performs erasure decoding/recovery work in *stripping* case
> utilizing erasure codec and coder provided by the codec framework.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
