[jira] Reopened: (HADOOP-1989) Add support for simulated Data Nodes - helpful for testing and performance benchmarking of the Name Node without having a large cluster

["Doug Cutting (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HADOOP-1989?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Doug Cutting reopened HADOOP-1989:
----------------------------------


Sorry, I'm coming in late here, but the 'datanodecluster' command should not be added to bin/hadoop, since it's not a command for end-users, but only for testing.  It can easily be run by developers using the slightly more verbose syntax:
{noformat}
bin/hadoop org.apache.hadoop.dfs.DataNodeCluster
{noformat}
The shortcut commands in bin/hadoop should be for end users, not developers.


> Add support for simulated Data Nodes  - helpful for testing and performance benchmarking of the Name Node without having a large cluster
> ----------------------------------------------------------------------------------------------------------------------------------------
>
>                 Key: HADOOP-1989
>                 URL: https://issues.apache.org/jira/browse/HADOOP-1989
>             Project: Hadoop
>          Issue Type: Improvement
>          Components: dfs
>    Affects Versions: 0.16.0
>            Reporter: Sanjay Radia
>            Assignee: Sanjay Radia
>            Priority: Minor
>             Fix For: 0.16.0
>
>         Attachments: SimulatedStoragePatchSubmit.txt, SimulatedStoragePatchSubmit5.txt, SimulatedStoragePatchSubmit6.txt, SimulatedStoragePatchSubmit7.txt, SimulatedStoragePatchSubmit8.txt
>
>
> Proposal is to add an implementation for a Simulated Data Node.
> This will 
>   - allow one to test certain parts of the system (especially the Name Node, protocols) much more easily and efficiently.
>   - allow one to run performance benchmarks on the Name node without having a large cluster.
>   - Inject faults for testing (e.g. one can add random faults based probability parameters).
> The idea is that the Simulated Data Node will
>  - discard any data written to blocks (but remember the blocks and their sizes)
>  - generate fixed data on the fly when blocks are read (e.g. block is fixed set of bytes or repeated sequence of strings).
> The Simulated Data Node can also be used for fault injection.
> The data node can be parameterized with probabilities that allow one to control:
>   - Delays on reads and writes, creates, etc
>   - IO Exceptions
>  - Loss of blocks 
>  - Failures

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.