What is difference between cp and DistCp?

2) distcp runs a MR job behind and cp command just invokes the FileSystem copy command for every file. 3) If there are existing jobs running, then distcp might take time depending memory/resources consumed by already running jobs.In this case cp would be better. 4) Also, distcp will work between 2 clusters.

Is DistCp faster than cp?

DistCp (distributed copy) is a tool used for large inter/intra-cluster copying. DistCp is very efficient because it uses MapReduce to copy the files or datasets and this means the copy operation is distributed across multiple nodes in your cluster and hence it is very effective as opposed to a hadoop fs -cp operation.

What is hadoop DistCp?

DistCp (distributed copy) is a tool used for large inter/intra-cluster copying. It uses MapReduce to effect its distribution, error handling and recovery, and reporting. It expands a list of files and directories into input to map tasks, each of which will copy a partition of the files specified in the source list.

Can we use DistCp within same cluster?

Copying Data Within a Cluster This represents the hostname of the machine designated as your cluster’s namenode. The first command is good for moving of manageable files, while DistCP is more for moving big ol’ data. Best of all, it submits and executes to the job tracker as a Map-Reduce job. Truly a parallel copy.

What is the difference between put and copyFromLocal in Hadoop?

-copyFromLocal this command can copy only one source ie from local file system to destination file system. -put command can copy single and multiple sources from local file system to destination file system.

How can I improve my DistCp performance?

Improving DistCp Performance

Working with Local Stores.
Accelerating File Listing.
Controlling the Number of Mappers and Their Bandwidth.

How can I make my DistCp faster?

You can run the DistCp job with a ‘-strategy dynamic’ flag that will “dynamically” size maps enabling the faster or more responsive nodes to copy more data than slower or busy nodes.

Is DistCp secure?

Security settings dictate whether DistCp should be run on the source cluster or the destination cluster. The general rule-of-thumb is that if one cluster is secure and the other is not secure, DistCp should be run from the secure cluster — otherwise there may be security- related issues.

What is difference between GET and copyToLocal?

The get command copies HDFS-based files to the local Linux file system. The get command is similar to copyToLocal, except that copyToLocal must copy to a local Linux file system based file. This example copies the HDFS-based file agent2. cfg to the local Linux directory (” .

What file system does put and copyFromLocal belong to *?

The first argument of copyFromLocal is restricted to a location in the location filesystem whereas you are not restricted to the local file system with the put command. With put you can specify the filesystem scheme (file:// or hdfs://) to distinguish between local filesystem and HDFS.

Does DistCp overwrite?

The DistCp -overwrite option overwrites target files even if they exist at the source, or if they have the same contents. The -update and -overwrite options warrant further discussion, since their handling of source-paths varies from the defaults in a very subtle manner.

What are HDFS commands?

HDFS Commands

ls: This command is used to list all the files.
mkdir: To create a directory.
touchz: It creates an empty file.
copyFromLocal (or) put: To copy files/folders from local file system to hdfs store.
cat: To print file contents.
copyToLocal (or) get: To copy files/folders from hdfs store to local file system.

What is distcp in Hadoop?

Certify and Increase Opportunity. DistCP is the shortform of Distributed Copy in context of Apache Hadoop. It is basically a tool which can be used in case we need to copy large amount of data/files in inter/intra-cluster setup.

What is copylisting in distcp Hadoop?

They examine the contents of the source-paths (files/directories, including wild-cards), and record all paths that need copy into a SequenceFile, for consumption by the DistCp Hadoop Job. The main classes in this module include: CopyListing: The interface that should be implemented by any copy-listing-generator implementation.

What is distcp version 2 (distributed copy)?

DistCP takes a list of files (in case of multiple files) and distribute the data between multiple Map tasks and these map tasks copy the data portion assigned to them to the destination. DistCp Version 2 (distributed copy) is a tool used for large inter/intra-cluster copying.

What is the difference between HFTP and distcp?

The default port for HFTP is 50070 and the default port for HDFS is 8020. HFTP is a read-only protocol, which could be used for source cluster not for destination cluster. HFTP cannot be used for to copy the data from insecure to secure cluster. Distcp has one disadvantage of not having the option to merge the data.