[ https://issues.apache.org/jira/browse/HADOOP-1989?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Sanjay Radia updated HADOOP-1989: --------------------------------- Attachment: SimulatedStoragePatchSubmit5.txt The attached patch addresses Konstantine's feedback on the previous patch. It also add a new class DataNodeCluster that allows one to run a DataNode cluster in a single address space (the name node can be in a separate address space). This class allows one to run multiple instances of the simulated data node in a single VM; this is useful for benchmarking with a real Name node and a large number of simulated data nodes. The hadoop command has been modified to allow one to run this as: bin/hadoop datanodecluster > 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 > Reporter: Sanjay Radia > Priority: Minor > Attachments: SimulatedStoragePatchSubmit.txt, > SimulatedStoragePatchSubmit5.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.