I've tried running
hadoop fs -getmerge
on a directory of .deflate files. The result is a compressed file on my local machine.
What is the easiest way to download the entire directory in uncompressed format on to my local machine?
Try this:
hadoop fs -text /some/where/job-output/part-*
Related
After running a sqoop jobs I got the files .deflate extension (compression is configured by default). I know that I can show the file content using following command:
hadoop fs -text <file>
How can I copy this result to my local folder?
Just redirect output to some local file
hadoop fs -text hdfs_path > local_file.txt
I have some snappy compressed Snappy files in a directory in HDFS. I need to decompress each file and load into a Text file. Any Hadoop DFS commands are available? I am new here. Kindly help.
Thanks,
Praveen.
One way you can achieve it is via -text hadoop command
hadoop fs -text /hdfs_path/hdfs_file.snappy > some_unix_file.txt
hadoop fs -put some_unix_file.txt /hdfs_path
i'm beginner in hadoop, when i use
Hadoop fs -ls /
And
Hadoop fs - mkdir /pathname
Every thing is ok, but i want to use my csv file in hadoop, my file is in c drive, i used -put and wget and copyfromlocal commands like these:
Hadoop fs -put c:/ path / myhadoopdir
Hadoop fs copyFromLoacl c:/...
Wget ftp://c:/...
But in two of above it errors in no such file or directory /myfilepathinc:
And for the third
Unable to resolve host address"c"
Thanks for your help
Looking at your command, it seems that there could be couple of reasons for this issue.
Hadoop fs -put c:/ path / myhadoopdir
Hadoop fs copyFromLoacl c:/...
Use hadoop fs -copyFromLocal correctly.
Check your local file permission. You have to give full access to that file.
You have to give your absolute path location both in local and in hdfs.
Hope it will work for you.
salmanbw's answer is exact. To be more clear.
Suppose your file is "c:\testfile.txt", use the command below.
And also make sure you have write permission to your directory in HDFS.
hadoop fs -copyFromLocal c:\testfile.txt /HDFSdir/testfile.txt
How to copy file from HDFS to the local file system . There is no physical location of a file under the file , not even directory . how can i moved them to my local for further validations.i am tried through winscp .
bin/hadoop fs -get /hdfs/source/path /localfs/destination/path
bin/hadoop fs -copyToLocal /hdfs/source/path /localfs/destination/path
Point your web browser to HDFS WEBUI(namenode_machine:50070), browse to the file you intend to copy, scroll down the page and click on download the file.
In Hadoop 2.0,
hdfs dfs -copyToLocal <hdfs_input_file_path> <output_path>
where,
hdfs_input_file_path maybe obtained from http://<<name_node_ip>>:50070/explorer.html
output_path is the local path of the file, where the file is to be copied to.
you may also use get in place of copyToLocal.
In order to copy files from HDFS to the local file system the following command could be run:
hadoop dfs -copyToLocal <input> <output>
<input>: the HDFS directory path (e.g /mydata) that you want to copy
<output>: the destination directory path (e.g. ~/Documents)
Update: Hadoop is deprecated in Hadoop 3
use hdfs dfs -copyToLocal <input> <output>
you can accomplish in both these ways.
1.hadoop fs -get <HDFS file path> <Local system directory path>
2.hadoop fs -copyToLocal <HDFS file path> <Local system directory path>
Ex:
My files are located in /sourcedata/mydata.txt
I want to copy file to Local file system in this path /user/ravi/mydata
hadoop fs -get /sourcedata/mydata.txt /user/ravi/mydata/
If your source "file" is split up among multiple files (maybe as the result of map-reduce) that live in the same directory tree, you can copy that to a local file with:
hadoop fs -getmerge /hdfs/source/dir_root/ local/destination
This worked for me on my VM instance of Ubuntu.
hdfs dfs -copyToLocal [hadoop directory] [local directory]
1.- Remember the name you gave to the file and instead of using hdfs dfs -put. Use 'get' instead. See below.
$hdfs dfs -get /output-fileFolderName-In-hdfs
if you are using docker you have to do the following steps:
copy the file from hdfs to namenode (hadoop fs -get output/part-r-00000 /out_text).
"/out_text" will be stored on the namenode.
copy the file from namenode to local disk by (docker cp namenode:/out_text output.txt)
output.txt will be there on your current working directory
bin/hadoop fs -put /localfs/destination/path /hdfs/source/path
I have an Elastic Map Reduce job which is writing some files in S3 and I want to concatenate all the files to produce a unique text file.
Currently I'm manually copying the folder with all the files to our HDFS (hadoop fs copyFromLocal), then I'm running hadoop fs -getmerge and hadoop fs copyToLocal to obtain the file.
is there anyway to use hadoop fs directly on S3?
Actually, this response about getmerge is incorrect. getmerge expects a local destination and will not work with S3. It throws an IOException if you try and responds with -getmerge: Wrong FS:.
Usage:
hadoop fs [generic options] -getmerge [-nl] <src> <localdst>
An easy way (if you are generating a small file that fits on the master machine) is to do the following:
Merge the file parts into a single file onto the local machine (Documentation)
hadoop fs -getmerge hdfs://[FILE] [LOCAL FILE]
Copy the result file to S3, and then delete the local file (Documentation)
hadoop dfs -moveFromLocal [LOCAL FILE] s3n://bucket/key/of/file
I haven't personally tried the getmerge command myself but hadoop fs commands on EMR cluster nodes support S3 paths just like HDFS paths. For example, you can SSH into the master node of your cluster and run:
hadoop fs -ls s3://<my_bucket>/<my_dir>/
The above command will list of out all the S3 objects under the specified directory path.
I would expect hadoop fs -getmerge to work the same way. So, just use full S3 paths (starting with s3://) instead of HDFS paths.