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excludeOlder Versions|Additional Resources|Related Links|Related Information

Snap type:

Write

Description:

This Snap reads a binary data stream from the input view and writes it to a specified file destination. Possible file destinations include: SLDB, HTTP, S3, FTP, SFTP, FTPS, or HDFS. If File permissions for the file are provided, the Snap set those permissions to the file.

  • Expected upstream Snaps: Any Snap with a binary output view can be connected upstream, such as CSV Formatter, JSON Formatter, XML Formatter, or File Reader.
  • Expected downstream Snaps: Downstream Snap is optional. Any Snap with a document input view can be connected downstream.
  • Expected input: Any binary data stream
  • Expected output: The output view for this Snap is optional. If an output view is open and the file write action is successful, the output view provides a document with information on the filename, result, and original data. An example is:
Code Block
{
        "filename": "ftp://ftp.Snaplogic.com/home/qatest/user_manual.pdf",
        "result": "overwritten",
        "original": {
            "content-type" : "application/json"
        }
    }
The value of the "result" field can be "overwritten", "created", "ignored", or "appended". The value "ignored" indicates that the Snap did not overwrite the existing file because the value of the File action property is "IGNORE".


Prerequisites:

Multiexcerpt include macro
nameEC2Prerequisite
pageFile Reader

Support and limitations:
  • Works in Ultra Pipelines.

  • Files uploaded to SLFS have a 100-MB per file limit. 

    Note
    titleNote

    This limit does not apply when writing to external storage. 


Known Issues:This Snap does not create an output file when using the input from SAS Generator Snap configured with only the DELETE SAS permission. This is not the case when the target file exists.
Account: 

This Snap uses account references created on the Accounts page of SnapLogic Manager to handle access to this endpoint. This Snap supports several account types, as listed in the table below, or no account.

 See 

 See Configuring Binary

Account

Accounts for information on setting up

these types of accounts. Account

accounts that work with this Snap.

Account types supported by each protocol are as follows:

Protocol Account types
sldbno account
s3AWS S3, S3 Dynamic
ftpBasic Auth
sftpBasic Auth, SSH Auth 
ftpsBasic Auth
hdfsno account
webhdfsno account
httpno account
httpsoptional account
smbSMB
fileno account
wasbAzure Storage
wasbs

Azure Storage

gs

Google Storage

adl

Azure Data lake 


Note

The FTPS file protocol works only in explicit mode. The implicit mode is not supported.

Required settings for account types are as follows:

 Account Type Settings
Basic Auth

Username, Password

AWS S3Access-key ID, Secret key, Server-side encryption
S3 DynamicAccess-key ID, Secret key, Security token, Server-side encryption
SSH AuthUsername, Private key, Key Passphrase
SMBDomain, Username, Password
Azure StorageAccount name, Primary access key
Google StorageApproval prompt, Application scope, Auto-refresh token
Azure Data Lake Tenant ID, Access ID, Secret Key

  

Note

SnapLogic automatically appends "azuredatalakestore.net" to the store name you specify when using Azure Data Lake; therefore, you do not need to add 'azuredatalakestore.net' to the URI while specifying the directory.


Views:


InputThis Snap has exactly one binary input view, where it gets the binary data to be written to the file specified in the File Name property.
OutputThis Snap has at most one document output view.
ErrorThis Snap has at most one document error view and produces zero or more documents in the view.


Settings

Label



Excerpt

Required. The name for the Snap. You can modify this to be more specific, especially if you have more than one of the same Snap in your Pipeline.


File name 

Required. This property specifies the URL for the destination file, which the binary data read from the input view is written to. It may start with one of the following protocols:

  • http:
  • https:
  • s3:
  • sftp:
  • ftp:
  • ftps:
  • hdfs:
  • webhdfs:
  • sldb:
  • smb:

  • file: (only for use with a Groundplex)

  • wasb:

  • wasbs:

  • gs:

  • adl: 

For SLDB files, if you enter:

  • just a file name, such as file.csv, then it writes the file to: /<org>/projects/<pipeline project>/file1.csv (where <org> is your organization name and <pipeline project> is the project where the pipeline is stored) if the pipeline is in a project other than the shared project.

  • shared/file1.csv, then it writes the file to: /<org>/shared/file1.csv.

The Snap can write a file to its own project directory or the shared project, and cannot write it to another project directory.

For S3, your account must have full access.
The File property can be a JavaScript expression with the "=" button pressed.
For example, if the "File" property is:
                "sldb:///out_" + Date.now() + ".csv"
then the evaluated filename can be:

sldb:///out_2013-11-13T00:22:31.880Z.csv

Fields in the binary header can be also be accessed when computing a file name. For example, if a File Reader Snap was directly connected to a File Writer, you could access the "content-location" header field to get the original path to the file.

You could then compute a new file name based on the old one, for instance, to make a backup file:
    $['content-location'].match('/([^/]+)$')[1] + '.backup'

For http: and https: protocols, the Snap uses http PUT method only. This property should have the syntax:

        [protocol]://[host][:port]/[path]

Please note "://" is a separator between the file protocol and the rest of the URL and the host name and the port number should be between "://" and "/". If the port number is omitted, a default port for the protocol is used. The hostname and port number are omitted in the sldb and s3 protocols. 


This property should be an absolute path for all protocols except sldb.

The file:/// protocol is supported only on Groundplex. In Cloudplex configurations, please use sldb or other file protocols. When using the file:/// protocol, the file access is conducted using the permissions of the user in whose name the Snaplex is running (by default Snapuser). File system access is to be used with caution, and it is the customer's own responsibility to ensure that file system is cleaned up after use. 

For HDFS, if you want to be able to suggest information, use the HDFS Writer Snap. 

For webhdfs, make sure webhdfs is enabled on your hdfs server and use the file protocol "webhdfs://" instead of "hdfs://". Everything else is the same as hdfs.

Examples: 

  • s3:///<S3_bucket_name>@s3.<region_name>.amazonaws.com/<path>

    For region names and their details, see AWS Regions and Endpoints.
    Example: s3:///mybucket@s3.eu-west-1.amazonaws.com/test.json

  • sftp://ftp.snaplogic.com:22/dir/filename
  • smb://smb.Snaplogic.com:445/test_files/csv/input.csv
  • _filename (A key/value pair with "filename" key should be defined as a pipeline parameter.)
  • file:///D:/testFolder/  (if the Snap is executed in the Windows Groundplex and needs to access D: drive)
  • wasb:///snaplogic/testDir/sampl/csv (to write 'sample.csv' file into the 'testDir' folder in the 'Snaplogic' container)
  • gs:///mybucket/csv/test.csv (to read 'test.csv' file in the 'csv/' folder of the 'mybucket' bucket)
  • adl://storename/folder/filename (to read the file from a location of the storage) 

Default value:  [None]

Note

When using expressions to build a file name, ensure that the resulting file name does not contain characters that are not supported by the target platform. For example, a file name that contains the special character ":" is not supported in SMB.


File action


Required. The action to perform if the file already exists. The available options include:

  • Overwrite - If Overwrite is selected, the Snap attempts to write the file without checking for the file's existence for a better performance, and the "fileAction" field will be "overwritten" in the output view data.
  • Append - Append is supported for file, FTP, FTPS and SFTP protocols only.
  • Ignore - If Ignore, it will not overwrite the file and will do nothing but write the status and file name to its output view.
  • Error -  If Error is selected, the error displays in the Pipeline Run Log. If an error view is defined, the error will be written there as well.


Note
For wasb:// and wasbs:// file protocols, only the Overwrite file action is supported.

Default value: Overwrite

Write empty file

If selected, an empty file is written when the incoming binary document has empty data. If there is no incoming document at the input view of the Snap, no file is written regardless of the value of the property.

Default value: Not selected.

Write header file


The binary data stream in the input view may contain header information about the binary data in the form of a document with key-value-pair map data. If this property is checked, the Snap writes a header file whose name is generated by appending ".header" to the value of the File name property. The same header information is also included in the output view data, as shown in the "Expected output" section above, under the key "original". Note that if the header has no keys other than Content-Type or Content-Encoding, the .header file will not be written

Default value: Not selected 


Validate after write


If selected, the Snap checks if the file exists after the completion of the file write. This may delay a few more seconds for the validation.

Default value: Not selected 

Number of retries

Specifies the maximum number of retry attempts when the Snap fails to write. If the value is larger than 0, the Snap first stores the input data in a temporary local file before writing to the target file.


Info

Ensure that the local drive has sufficient free disk space as large as the expected target file size.

Example:  3

Minimum value: 0

Default value: 0

Multiexcerpt include macro
nameretries
pageFile Reader

Retry interval (seconds)

Specifies the minimum number of seconds for which the Snap must wait before attempting recovery from a network failure.

Example:  3

Minimum value: 1

Default value: 1

File permissions for various users


File permission sets to be assigned to the file.
Note:

  • Supported for sftp, ftp, ftps, file, hdfs and webhdfs protocols only.
  • FTP/FTPS servers on Windows machines may not be supported.


User type

It should be 'owner' or 'group' or 'others'. Each row can have only one user type and each user type should appear only once. Please select one from the suggested list.

Example:  owner, group, others

File permissions

It can be any combination of {read, write, execute} separated by '+' character. Please select one from the suggested list.

Example:  read, write, execute, read+write, read+write+execute
 


User type


The user type to assign the permissions. This field is case-insensitive. Suggestible options are:

  • owner
  • group
  • others
Note

Specify at most one row per user type.


File permissions


Specify any combination of {read, write, execute}, separated by a plus sign (+).  This field is case-insensitive. Suggestible options are:

  • read
  • write
  • execute
  • read+write
  • read+execute
  • write+execute
  • read+write+execute

Create directory if not present  


When selected, checks if the specified directory path exists and if it does not exist, creates a new directory. This property is not supported for HTTP, HTTPS, SLDB and SMB file protocols.

Default value: Not selected

Flush interval (kB)

Flush interval in kilobytes during the file upload. The Snap can flush a given size of data output stream written to the target file server. If the value is zero, the Snap flushes in maximum frequency after each byte block is written. Larger the value is, the less frequent flushes the Snap performs. Leave the property at default -1 for no flush during the upload. This property may help if the file upload experiences an intermittent failure. However, more frequent flushes will result in a slower file upload.

Example:   100

Default value:  -1

Multiexcerpt include macro
nameSASURI_Name
pageFile Reader
Multiexcerpt include macro
nameSASURI_Description
pageFile Reader

Multiexcerpt include macro
nameSnap Execution
pageSOAP Execute


Multiexcerpt include macro
nameExecution_Detail_Write
pageSOAP Execute

Examples

  • For SFTP files, if you attempt to write a file into a directory where you do not have a write access right, the write operation will fail with "access denied" error. When you get an SFTP account credential, it is also important to know where your home directory is, for example, 

    sftp://ftp.snaplogic.com/home/mrtest for username "mrtest"
     

  • HDFS Example

For HDFS file access, please use a SnapLogic on-premises Groundplex and make sure that its instance is within the Hadoop cluster and SSH authentication has already been established. You can access HDFS files in the same way as other file protocols in File Reader and File Writer Snaps. There is no need to use any account in the Snap. The Snap also supports the webhdfs protocol, which does not require a Groundplex and works for all versions of Hadoop. 

Note

HDFS 2.4.0 is supported for the hdfs protocol.


An example for HDFS is: 

Code Block
hdfs://<hostname>:<port number>/<path to folder>/<filename>


If Cloudera Hadoop Namenode is installed in AWS EC2 and its hostname is "ec2-54-198-212-134.compute-1.amazonaws.com" and its port number is 8020, then you would enter:

Code Block
hdfs://ec2-54-198-212-134.compute-1.amazonaws.com:8020/user/john/input/sample.csv


Expand
titleExample pipeline file for an sldb file write

Example pipeline file for an sldb file write as shown below: 

Image Modified

Common Error Messages

MessageCause

Reason:

Could not evaluate expression: filepath


Mismatched input ':' expecting {<EOF>, '||', '&&', '^', '==', '!=', '>', '<', '>=', '<=', '+', '-', '*', '/', '%', '?', '[', PropertyRef}.

Resolution:

Please check expression syntax

The expression toggle (=) is selected on the File name field, so it is trying to evaluate the filepath as an expression.


Click on the toggle to take the field out of expression mode.

Reason:

Failure:
filename is undefined

filename was not found in the containing object.

Resolution:

Please check expression syntax and data types.

The expression toggle (=) is selected on the File name field, so it is trying to evaluate the filename as an expression.


Click on the toggle to take the field out of expression mode.

Downloads

Attachments
uploadfalse
oldfalse
patterns*.slp, *.zip

See Also

Insert excerpt
Binary Snap Pack
Binary Snap Pack
nopaneltrue