Setting Static IP in Raspberry PI

Setting static IP for Raspberry PI devices:

  1. Open the interfaces file
    • sudo nano /etc/network/interfaces
  2. You will find something written as
    • iface eth0 inet manual
    • change it to – iface eth0 inet static
  3.  Add the following after iface eth0 inet static as per the values:
    • dns-nameservers 8.8.8.8
    • address 192.168.1.81
    • netmask 255.255.255.0
    • broadcast 192.168.1.255
    • gateway 192.168.1.254
  4. Add the DNS server configs as below:
    • sudo nano /etc/dhcpcd.conf
    • Add the following : static domain_name_servers=172.26.1.50 8.8.8.8

Single node hadoop cluster using Cloudera Manager

  1. Launch an EC2 instance with minimum of 8/16GB RAM. (m4.large/m4.xlarge)
  2. Add the yum repository inside /etc/yum.repos.d/cloudera.repo like below:
    • Choose appropriate CDH version as per your requirement from RHEL6 / RHEL7
    • [cloudera-cdh5]
      # Packages for Cloudera Manager for Hadoop, Version 5.8.2, on RedHat or CentOS 6 x86_64
      name=Cloudera Manager for Hadoop, Version 5.8.2
      baseurl=http://archive.cloudera.com/cm5/redhat/6/x86_64/cm/5.8.2/
      gpgkey=http://archive.cloudera.com/cm5/redhat/6/x86_64/cm/RPM-GPG-KEY-cloudera
      gpgcheck=1
  3. Clean YUM repo : sudo yum clean all
  4. Java Installation
    • sudo yum install oracle-j2sdk1.7-1*
  5. Mysql install
    • yum install mysql-server
    • service mysqld start
    • /usr/bin/mysql_secure_installation – Set password
  6. Create cmdb,hivedb,huedb and whatever required as per the services you need
    1. create database cmdb;
      create user 'cmuser' identified by 'myPass@123';
      grant all on cmdb.* to 'cmuser' identified by 'myPass@123';
      grant all on cmdb.* to 'cmuser'@'localhost' identified by 'myPass@123';
      grant all on cmdb.* to 'cmuser'@'%' identified by 'myPass@123';
      grant all on cmdb.* to 'cmuser'@'<<hostname>>' identified by 'myPass@123';
      
      create database hivedb;
      create user 'hive' identified by 'myPass@123';
      grant all on hivedb.* to 'hive' identified by 'myPass@123';
      grant all on hivedb.* to 'hive'@'localhost' identified by 'myPass@123';
      grant all on hivedb.* to 'hive'@'%' identified by 'myPass@123';
      grant all on hivedb.* to 'hive'@'<<hostname>>' identified by 'myPass@123';
  7. Install cloudera-manager-server
    1. yum install cloudera-scm-sever
  8. Install cloudera-manager-agent
    1. yum install cloudera-scm-agent
  9. Edit db.properties like below – sudo vi /etc/cloudera-scm-server/db.properties
    1. # Copyright (c) 2012 Cloudera, Inc. All rights reserved.
      #
      # This file describes the database connection.
      #
      # The database type
      # Currently 'mysql', 'postgresql' and 'oracle' are valid databases.
      com.cloudera.cmf.db.type=mysql
      # The database host
      # If a non standard port is needed, use 'hostname:port'
      com.cloudera.cmf.db.host=localhost
      # The database name
      com.cloudera.cmf.db.name=cmdb
      
      # The database user
      com.cloudera.cmf.db.user=cmuser
      
      # The database user's password
      com.cloudera.cmf.db.password=myPass@123

       

  10. sudo yum install mysql-connector-java
  11. Start the scm-server
    1. sudo service cloudera-scm-server start
      sudo service cloudera-scm-server start
  12. Start the scm-agent
    1. sudo service cloudera-scm-server start
      sudo service cloudera-scm-server start
  13. http://<<hostname/ipaddress>&gt;:7180/ (check inbound rules/disable firewall if not opening)
  14. Continue the steps mentioned and complete the installation.
  15. Below are some commands which might be helpful for setting proper permissions for directories if something gets wrong during installation.
    1. chown -R yarn:yarn hadoop-yarn
      chown -R mapred:mapred hadoop-mapreduce
      chown -R hdfs:hdfs hadoop-hdfs
      chown -R httpfs:httpfs hadoop-httpfs
      chown -R kms:kms hadoop-kms
      chmod 770 /var/lib/hadoop-yarn
      chmod 770 /var/lib/hadoop-hdfs
      chmod 770 spark/
      chmod 770 oozie/
      chmod 770 hive/
      chmod 770 impala
      chmod 770 hbase

       

  16. This is completely verified, please let me know in the comments if you face any issues or need any help.

 

 

Hadoop commands

Overview

The File System (FS) shell includes various shell-like commands that directly interact with the Hadoop Distributed File System (HDFS) as well as other file systems that Hadoop supports, such as Local FS, HFTP FS, S3 FS, and others. The FS shell is invoked by:

bin/hadoop fs <args>

All FS shell commands take path URIs as arguments. The URI format is scheme://authority/path. For HDFS the scheme is hdfs, and for the Local FS the scheme is file. The scheme and authority are optional. If not specified, the default scheme specified in the configuration is used. An HDFS file or directory such as /parent/child can be specified as hdfs://namenodehost/parent/child or simply as /parent/child (given that your configuration is set to point to hdfs://namenodehost).

Most of the commands in FS shell behave like corresponding Unix commands. Differences are described with each of the commands. Error information is sent to stderr and the output is sent to stdout.

appendToFile

Usage: hdfs dfs -appendToFile <localsrc> ... <dst>

Append single src, or multiple srcs from local file system to the destination file system. Also reads input from stdin and appends to destination file system.

  • hdfs dfs -appendToFile localfile /user/hadoop/hadoopfile
  • hdfs dfs -appendToFile localfile1 localfile2 /user/hadoop/hadoopfile
  • hdfs dfs -appendToFile localfile hdfs://nn.example.com/hadoop/hadoopfile
  • hdfs dfs -appendToFile - hdfs://nn.example.com/hadoop/hadoopfile Reads the input from stdin.

Exit Code:

Returns 0 on success and 1 on error.

cat

Usage: hdfs dfs -cat URI [URI ...]

Copies source paths to stdout.

Example:

  • hdfs dfs -cat hdfs://nn1.example.com/file1 hdfs://nn2.example.com/file2
  • hdfs dfs -cat file:///file3 /user/hadoop/file4

Exit Code:

Returns 0 on success and -1 on error.

chgrp

Usage: hdfs dfs -chgrp [-R] GROUP URI [URI ...]

Change group association of files. The user must be the owner of files, or else a super-user. Additional information is in the Permissions Guide.

Options

  • The -R option will make the change recursively through the directory structure.

chmod

Usage: hdfs dfs -chmod [-R] <MODE[,MODE]... | OCTALMODE> URI [URI ...]

Change the permissions of files. With -R, make the change recursively through the directory structure. The user must be the owner of the file, or else a super-user. Additional information is in the Permissions Guide.

Options

  • The -R option will make the change recursively through the directory structure.

chown

Usage: hdfs dfs -chown [-R] [OWNER][:[GROUP]] URI [URI ]

Change the owner of files. The user must be a super-user. Additional information is in the Permissions Guide.

Options

  • The -R option will make the change recursively through the directory structure.

copyFromLocal

Usage: hdfs dfs -copyFromLocal <localsrc> URI

Similar to put command, except that the source is restricted to a local file reference.

Options:

  • The -f option will overwrite the destination if it already exists.

copyToLocal

Usage: hdfs dfs -copyToLocal [-ignorecrc] [-crc] URI <localdst>

Similar to get command, except that the destination is restricted to a local file reference.

count

Usage: hdfs dfs -count [-q] [-h] <paths>

Count the number of directories, files and bytes under the paths that match the specified file pattern. The output columns with -count are: DIR_COUNT, FILE_COUNT, CONTENT_SIZE FILE_NAME

The output columns with -count -q are: QUOTA, REMAINING_QUATA, SPACE_QUOTA, REMAINING_SPACE_QUOTA, DIR_COUNT, FILE_COUNT, CONTENT_SIZE, FILE_NAME

The -h option shows sizes in human readable format.

Example:

  • hdfs dfs -count hdfs://nn1.example.com/file1 hdfs://nn2.example.com/file2
  • hdfs dfs -count -q hdfs://nn1.example.com/file1
  • hdfs dfs -count -q -h hdfs://nn1.example.com/file1

Exit Code:

Returns 0 on success and -1 on error.

cp

Usage: hdfs dfs -cp [-f] [-p | -p[topax]] URI [URI ...] <dest>

Copy files from source to destination. This command allows multiple sources as well in which case the destination must be a directory.

‘raw.*’ namespace extended attributes are preserved if (1) the source and destination filesystems support them (HDFS only), and (2) all source and destination pathnames are in the /.reserved/raw hierarchy. Determination of whether raw.* namespace xattrs are preserved is independent of the -p (preserve) flag.

Options:

  • The -f option will overwrite the destination if it already exists.
  • The -p option will preserve file attributes [topx] (timestamps, ownership, permission, ACL, XAttr). If -p is specified with no arg, then preserves timestamps, ownership, permission. If -pa is specified, then preserves permission also because ACL is a super-set of permission. Determination of whether raw namespace extended attributes are preserved is independent of the -p flag.

Example:

  • hdfs dfs -cp /user/hadoop/file1 /user/hadoop/file2
  • hdfs dfs -cp /user/hadoop/file1 /user/hadoop/file2 /user/hadoop/dir

Exit Code:

Returns 0 on success and -1 on error.

du

Usage: hdfs dfs -du [-s] [-h] URI [URI ...]

Displays sizes of files and directories contained in the given directory or the length of a file in case its just a file.

Options:

  • The -s option will result in an aggregate summary of file lengths being displayed, rather than the individual files.
  • The -h option will format file sizes in a “human-readable” fashion (e.g 64.0m instead of 67108864)

Example:

  • hdfs dfs -du /user/hadoop/dir1 /user/hadoop/file1 hdfs://nn.example.com/user/hadoop/dir1

Exit Code: Returns 0 on success and -1 on error.

dus

Usage: hdfs dfs -dus <args>

Displays a summary of file lengths.

Note: This command is deprecated. Instead use hdfs dfs -du -s.

expunge

Usage: hdfs dfs -expunge

Empty the Trash. Refer to the HDFS Architecture Guide for more information on the Trash feature.

get

Usage: hdfs dfs -get [-ignorecrc] [-crc] <src> <localdst>

Copy files to the local file system. Files that fail the CRC check may be copied with the -ignorecrc option. Files and CRCs may be copied using the -crc option.

Example:

  • hdfs dfs -get /user/hadoop/file localfile
  • hdfs dfs -get hdfs://nn.example.com/user/hadoop/file localfile

Exit Code:

Returns 0 on success and -1 on error.

getfacl

Usage: hdfs dfs -getfacl [-R] <path>

Displays the Access Control Lists (ACLs) of files and directories. If a directory has a default ACL, then getfacl also displays the default ACL.

Options:

  • -R: List the ACLs of all files and directories recursively.
  • path: File or directory to list.

Examples:

  • hdfs dfs -getfacl /file
  • hdfs dfs -getfacl -R /dir

Exit Code:

Returns 0 on success and non-zero on error.

getfattr

Usage: hdfs dfs -getfattr [-R] -n name | -d [-e en] <path>

Displays the extended attribute names and values (if any) for a file or directory.

Options:

  • -R: Recursively list the attributes for all files and directories.
  • -n name: Dump the named extended attribute value.
  • -d: Dump all extended attribute values associated with pathname.
  • -e encoding: Encode values after retrieving them. Valid encodings are “text”, “hex”, and “base64”. Values encoded as text strings are enclosed in double quotes (“), and values encoded as hexadecimal and base64 are prefixed with 0x and 0s, respectively.
  • path: The file or directory.

Examples:

  • hdfs dfs -getfattr -d /file
  • hdfs dfs -getfattr -R -n user.myAttr /dir

Exit Code:

Returns 0 on success and non-zero on error.

getmerge

Usage: hdfs dfs -getmerge <src> <localdst> [addnl]

Takes a source directory and a destination file as input and concatenates files in src into the destination local file. Optionally addnl can be set to enable adding a newline character at the end of each file.

ls

Usage: hdfs dfs -ls [-R] <args>

Options:

  • The -R option will return stat recursively through the directory structure.

For a file returns stat on the file with the following format:

permissions number_of_replicas userid groupid filesize modification_date modification_time filename

For a directory it returns list of its direct children as in Unix. A directory is listed as:

permissions userid groupid modification_date modification_time dirname

Example:

  • hdfs dfs -ls /user/hadoop/file1

Exit Code:

Returns 0 on success and -1 on error.

lsr

Usage: hdfs dfs -lsr <args>

Recursive version of ls.

Note: This command is deprecated. Instead use hdfs dfs -ls -R

mkdir

Usage: hdfs dfs -mkdir [-p] <paths>

Takes path uri’s as argument and creates directories.

Options:

  • The -p option behavior is much like Unix mkdir -p, creating parent directories along the path.

Example:

  • hdfs dfs -mkdir /user/hadoop/dir1 /user/hadoop/dir2
  • hdfs dfs -mkdir hdfs://nn1.example.com/user/hadoop/dir hdfs://nn2.example.com/user/hadoop/dir

Exit Code:

Returns 0 on success and -1 on error.

moveFromLocal

Usage: hdfs dfs -moveFromLocal <localsrc> <dst>

Similar to put command, except that the source localsrc is deleted after it’s copied.

moveToLocal

Usage: hdfs dfs -moveToLocal [-crc] <src> <dst>

Displays a “Not implemented yet” message.

mv

Usage: hdfs dfs -mv URI [URI ...] <dest>

Moves files from source to destination. This command allows multiple sources as well in which case the destination needs to be a directory. Moving files across file systems is not permitted.

Example:

  • hdfs dfs -mv /user/hadoop/file1 /user/hadoop/file2
  • hdfs dfs -mv hdfs://nn.example.com/file1 hdfs://nn.example.com/file2 hdfs://nn.example.com/file3 hdfs://nn.example.com/dir1

Exit Code:

Returns 0 on success and -1 on error.

put

Usage: hdfs dfs -put <localsrc> ... <dst>

Copy single src, or multiple srcs from local file system to the destination file system. Also reads input from stdin and writes to destination file system.

  • hdfs dfs -put localfile /user/hadoop/hadoopfile
  • hdfs dfs -put localfile1 localfile2 /user/hadoop/hadoopdir
  • hdfs dfs -put localfile hdfs://nn.example.com/hadoop/hadoopfile
  • hdfs dfs -put - hdfs://nn.example.com/hadoop/hadoopfile Reads the input from stdin.

Exit Code:

Returns 0 on success and -1 on error.

rm

Usage: hdfs dfs -rm [-f] [-r|-R] [-skipTrash] URI [URI ...]

Delete files specified as args.

Options:

  • The -f option will not display a diagnostic message or modify the exit status to reflect an error if the file does not exist.
  • The -R option deletes the directory and any content under it recursively.
  • The -r option is equivalent to -R.
  • The -skipTrash option will bypass trash, if enabled, and delete the specified file(s) immediately. This can be useful when it is necessary to delete files from an over-quota directory.

Example:

  • hdfs dfs -rm hdfs://nn.example.com/file /user/hadoop/emptydir

Exit Code:

Returns 0 on success and -1 on error.

rmr

Usage: hdfs dfs -rmr [-skipTrash] URI [URI ...]

Recursive version of delete.

Note: This command is deprecated. Instead use hdfs dfs -rm -r

setfacl

Usage: hdfs dfs -setfacl [-R] [-b|-k -m|-x <acl_spec> <path>]|[--set <acl_spec> <path>]

Sets Access Control Lists (ACLs) of files and directories.

Options:

  • -b: Remove all but the base ACL entries. The entries for user, group and others are retained for compatibility with permission bits.
  • -k: Remove the default ACL.
  • -R: Apply operations to all files and directories recursively.
  • -m: Modify ACL. New entries are added to the ACL, and existing entries are retained.
  • -x: Remove specified ACL entries. Other ACL entries are retained.
  • –set: Fully replace the ACL, discarding all existing entries. The acl_spec must include entries for user, group, and others for compatibility with permission bits.
  • acl_spec: Comma separated list of ACL entries.
  • path: File or directory to modify.

Examples:

  • hdfs dfs -setfacl -m user:hadoop:rw- /file
  • hdfs dfs -setfacl -x user:hadoop /file
  • hdfs dfs -setfacl -b /file
  • hdfs dfs -setfacl -k /dir
  • hdfs dfs -setfacl --set user::rw-,user:hadoop:rw-,group::r--,other::r-- /file
  • hdfs dfs -setfacl -R -m user:hadoop:r-x /dir
  • hdfs dfs -setfacl -m default:user:hadoop:r-x /dir

Exit Code:

Returns 0 on success and non-zero on error.

setfattr

Usage: hdfs dfs -setfattr -n name [-v value] | -x name <path>

Sets an extended attribute name and value for a file or directory.

Options:

  • -b: Remove all but the base ACL entries. The entries for user, group and others are retained for compatibility with permission bits.
  • -n name: The extended attribute name.
  • -v value: The extended attribute value. There are three different encoding methods for the value. If the argument is enclosed in double quotes, then the value is the string inside the quotes. If the argument is prefixed with 0x or 0X, then it is taken as a hexadecimal number. If the argument begins with 0s or 0S, then it is taken as a base64 encoding.
  • -x name: Remove the extended attribute.
  • path: The file or directory.

Examples:

  • hdfs dfs -setfattr -n user.myAttr -v myValue /file
  • hdfs dfs -setfattr -n user.noValue /file
  • hdfs dfs -setfattr -x user.myAttr /file

Exit Code:

Returns 0 on success and non-zero on error.

setrep

Usage: hdfs dfs -setrep [-R] [-w] <numReplicas> <path>

Changes the replication factor of a file. If path is a directory then the command recursively changes the replication factor of all files under the directory tree rooted at path.

Options:

  • The -w flag requests that the command wait for the replication to complete. This can potentially take a very long time.
  • The -R flag is accepted for backwards compatibility. It has no effect.

Example:

  • hdfs dfs -setrep -w 3 /user/hadoop/dir1

Exit Code:

Returns 0 on success and -1 on error.

stat

Usage: hdfs dfs -stat URI [URI ...]

Returns the stat information on the path.

Example:

  • hdfs dfs -stat path

Exit Code: Returns 0 on success and -1 on error.

tail

Usage: hdfs dfs -tail [-f] URI

Displays last kilobyte of the file to stdout.

Options:

  • The -f option will output appended data as the file grows, as in Unix.

Example:

  • hdfs dfs -tail pathname

Exit Code: Returns 0 on success and -1 on error.

test

Usage: hdfs dfs -test -[ezd] URI

Options:

  • The -e option will check to see if the file exists, returning 0 if true.
  • The -z option will check to see if the file is zero length, returning 0 if true.
  • The -d option will check to see if the path is directory, returning 0 if true.

Example:

  • hdfs dfs -test -e filename

text

Usage: hdfs dfs -text <src>

Takes a source file and outputs the file in text format. The allowed formats are zip and TextRecordInputStream.

touchz

Usage: hdfs dfs -touchz URI [URI ...]

Create a file of zero length.

Example:

  • hdfs dfs -touchz pathname

Exit Code: Returns 0 on success and -1 on error.

Kafka partitions deletion

Kafka way:

  • delete.topic.enable=true
  • bin/kafka-topics.sh --delete --zookeeper localhost:2181 --topic <topic_name>
  • The Kafka way of deleting topics wont work sometimes as it will just mark the topic for deletion.
  • So we must delete the topics and partitions manually and remove their data from Zookeeper also.

Manual way: Check this link

  1. Stop all the Kafka brokers
    1. sudo supervisorctl stop kafka-broker
  2. Login to all Kafka broker nodes and delete the topics/partitions manually
    • sudo rm -rf <kafka_data_dir>/<topic_name>*
    • The Kafka topic location will be mentioned in Kafka service configs
  3. Now lets delete from Zookeeper
    • Connect to any of the zookeeper node using any of commands below
    • rmr /config/topics/<topic_name>
      rmr /brokers/topics/<topic_name>
      rmr /admin/delete_topics/<topic_name>
  4. Verify the topic directory is deleted in zookeeper:
    • ls <path>
      
  5. Start the Kafka brokers back up:
    1. sudo supervisorctl start kafka-broker
  6. Command to create a Kafka topic again:
    1. bin/kafka-topics.sh --zookeeper ${zookeeper_server} --create --topic $topic --partitions=$pars --replication-factor $rep --config retention.ms=$ret