To use Mesos from Spark, you need a Spark binary package available in a place accessible by Mesos, and a Spark driver program configured to connect to Mesos. Uploading Spark Package:
Download a Spark binary package from the Spark download page
Upload to hdfs/http/s3 To host on HDFS, use the Hadoop fs put command: hadoop fs -put spark-2.0.1.tar.gz /path/to/spark-2.0.1.tar.gz Using a Mesos Master URL:
The Master URLs for Mesos are in the form mesos://host:5050 for a single-master Mesos cluster, or mesos://zk://host1:2181,host2:2181,host3:2181/mesos for a multi-master Mesos cluster using ZooKeeper. Client Mode:
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val conf = newSparkConf()
.setMaster("mesos://HOST:5050")
.setAppName("My app")
.set("spark.executor.uri", "<path to spark-2.0.1.tar.gz uploaded above>")
The Read and Write operations from Client into Hfile can be shown in below diagram.
Step 1) Client wants to write data and in turn first communicates with Regions server and then regions
Step 2) Regions contacting memstore for storing associated with the column family
Step 3) First data stores into Memstore, where the data is sorted and after that it flushes into HFile. The main reason for using Memstore is to store data in Distributed file system based on Row Key. Memstore will be placed in Region server main memory while HFiles are written into HDFS.
Step 4) Client wants to read data from Regions
Step 5) In turn Client can have direct access to Mem store, and it can request for data.
Step 6) Client approaches HFiles to get the data. The data are fetched and retrieved by the Client.
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:
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bin/hadoop fs <args>
All FS shell commands take path URIs as arguments. The URI format is
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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 ).
[-setBalancerBandwidth <bandwidth in bytes per second>]
设定负载均衡时使用的带宽
appendToFile
Usage: hadoop fs -appendToFile …
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.
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: hadoop fs -chmod [-R] 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: hadoop fs -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: hadoop fs -copyFromLocal 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: hadoop fs -copyToLocal [-ignorecrc] [-crc] URI
Similar to get command, except that the destination is restricted to a local file reference.
count
Usage: hadoop fs -count [-q] [-h] [-v]
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, PATHNAME
The output columns with -count -q are: QUOTA, REMAINING_QUATA, SPACE_QUOTA, REMAINING_SPACE_QUOTA, DIR_COUNT, FILE_COUNT, CONTENT_SIZE, PATHNAME
The -h option shows sizes in human readable format.
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.
Note: This command is deprecated. Instead use hadoop fs -du -s.
expunge
Usage: hadoop fs -expunge
Empty the Trash. Refer to the HDFS Architecture Guide for more information on the Trash feature.
find
Usage: hadoop fs -find … …
Finds all files that match the specified expression and applies selected actions to them. If no path is specified then defaults to the current working directory. If no expression is specified then defaults to -print.
The following primary expressions are recognised:
-name pattern
-iname pattern Evaluates as true if the basename of the file matches the pattern using standard file system globbing. If -iname is used then the match is case insensitive.
-print
-print0Always evaluates to true. Causes the current pathname to be written to standard output. If the -print0 expression is used then an ASCII NULL character is appended.
The following operators are recognised:
expression -a expression
expression -and expression
expression expression Logical AND operator for joining two expressions. Returns true if both child expressions return true. Implied by the juxtaposition of two expressions and so does not need to be explicitly specified. The second expression will not be applied if the first fails.
Example:
hadoop fs -find / -name test -print
Exit Code:
Returns 0 on success and -1 on error.
get
Usage: hadoop fs -get [-ignorecrc] [-crc]
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.
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:
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hadoop fs -getfattr -d /file
hadoop fs -getfattr -R -n user.myAttr /dir
Exit Code:
Returns 0 on success and non-zero on error.
getmerge
Usage: hadoop fs -getmerge [-nl]
Takes a source directory and a destination file as input and concatenates files in src into the destination local file. Optionally -nl can be set to enable adding a newline character (LF) at the end of each file.
Similar to put command, except that the source localsrc is deleted after it’s copied.
moveToLocal
Usage: hadoop fs -moveToLocal [-crc]
Displays a “Not implemented yet” message.
mv
Usage: hadoop fs -mv URI [URI …]
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.
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.
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.
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.
Usage: hadoop fs -setfattr -n name [-v value] | -x name
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.
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:
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hadoop fs -setrep -w 3 /user/hadoop/dir1
Exit Code:
Returns 0 on success and -1 on error.
stat
Usage: hadoop fs -stat [format] …
Print statistics about the file/directory at in the specified format. Format accepts filesize in blocks (%b), type (%F), group name of owner (%g), name (%n), block size (%o), replication (%r), user name of owner(%u), and modification date (%y, %Y). %y shows UTC date as “yyyy-MM-dd HH:mm:ss” and %Y shows milliseconds since January 1, 1970 UTC. If the format is not specified, %y is used by default.
Example:
hadoop fs -stat “%F %u:%g %b %y %n” /file
Exit Code: Returns 0 on success and -1 on error.
tail
Usage: hadoop fs -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:
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hadoop fs -tail pathname
Exit Code: Returns 0 on success and -1 on error.
test
Usage: hadoop fs -test -[defsz] URI
Options:
-d: f the path is a directory, return 0.
-e: if the path exists, return 0.
-f: if the path is a file, return 0.
-s: if the path is not empty, return 0.
-z: if the file is zero length, return 0.
Example:
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hadoop fs -test -e filename
text
Usage: hadoop fs -text
Takes a source file and outputs the file in text format. The allowed formats are zip and TextRecordInputStream.
touchz
Usage: hadoop fs -touchz URI [URI …]
Create a file of zero length.
Example:
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hadoop fs -touchz pathname
Exit Code: Returns 0 on success and -1 on error.
truncate
Usage: hadoop fs -truncate [-w]
Truncate all files that match the specified file pattern to the specified length.
Options:
The -w flag requests that the command waits for block recovery to complete, if necessary. Without -w flag the file may remain unclosed for some time while the recovery is in progress. During this time file cannot be reopened for append.
