Multi File Reader
In this article
Overview
You can use this read type Snap to read binary data from various sources such as SLDB, HTTP, S3, SFTP, HDFS, and produces a binary data stream at the output. Unlike the File Reader Snap, this Snap can read more than one file in the given directory and its subdirectories recursively.
Important
We plan to introduce additional S3 features exclusively in Amazon S3 Snaps, while Binary Snaps with S3 support will not contain these updates. Therefore, we recommend you to use the Amazon S3 Snap Pack for all your S3 operations within your pipelines. However, Binary Snaps will be retained as is to maintain backward compatibility, but be aware that we will no longer provide S3 support for the Binary Snaps.
Learn more: Migration from Binary Snaps to Amazon S3 Snaps.
Snap Type
Multi File Reader is a READ-type Snap.
Prerequisites
IAM Roles for Amazon EC2
The 'IAM_CREDENTIAL_FOR_S3' feature is used to access S3 files from EC2 Groundplex, without Access-key ID and Secret key in the AWS S3 account in the Snap. The IAM credential stored in the EC2 metadata is used to gain access rights to the S3 buckets. To enable this feature, set the Global properties (Key-Value parameters) and restart the JCC:jcc.jvm_options = -DIAM_CREDENTIAL_FOR_S3=TRUE
This feature is supported in the EC2-type Groundplex only. Learn more.
Connect to FTP server:
To connect to the FTP server that needs to reuse the session for data transfer over TLS protocol, add:
-DFTPS_SSL_TLS_PROTOCOL=TLSV1.2 (or) TLSV1.3
property as a JVM
option under the Global properties of the Node Properties tab:
Support for Ultra Pipelines
Works in Ultra Pipelines.
Limitations
- For most file protocols, the Snap behaves the same way in both Snaplex and Groundplex. However, the HDFS protocol works only in a Groundplex. The Hadoop cluster must open to the Groundplex server instance without any authentication.
- Do not use
sldb
as a file system or storage. File Assets are intended only for specialized files that a pipeline uses to reference specific data, such as accounts, expressions, or JAR files. Use a Cloud storage provider to store production data. File Assets should not be used as a file source or as a destination in production pipelines. When you configure the Multi File Reade, set the file path to a cloud provider or external file system.
Known Issues
This Snap Pack no longer natively supports RSA-SHA1 authentication with the Secure File Transfer Protocol (SFTP). To enable support for RSA-SHA1 authentication, set the following property from the Node Properties section of the Snaplex UI:
-Djsch.server_host_key=ssh-rsa -Djsch.client_pubkey=ssh-rsa
With the 4.33 GA release of the Binary Snap Pack, support for some algorithms for SFTP connection negotiation is removed for improved security and because we’ve updated the library used to connect to SFTP sources. If you want to revert to the previous settings, you can set the following jcc.jvm_options
from the Node Properties section of the Snaplex UI. To update Cloudplexes, contact SnapLogic Support.
-Djsch.kex=ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group14-sha1,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group1-sha1
-Djsch.server_host_key=ssh-rsa,ssh-dss,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521
-Djsch.client_pubkey=ssh-rsa,ssh-dss,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521
-Djsch.cipher=aes128-ctr,aes128-cbc,3des-ctr,3des-cbc,blowfish-cbc,aes192-ctr,aes192-cbc,aes256-ctr,aes256-cbc
-Djsch.check_ciphers=aes256-ctr,aes192-ctr,aes128-ctr,aes256-cbc,aes192-cbc,aes128-cbc,3des-ctr,arcfour,arcfour128,arcfour256
-Djsch.check_kexes=diffie-hellman-group14-sha1,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521
-Djsch.check_signatures=ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521
Snap Views
Type | Format | Number of Views | Examples of Upstream and Downstream Snaps | Description |
---|---|---|---|---|
Input | Document |
| N/A | N/A |
Output | Binary |
|
| Binary data read from the source specified in the Selected files property. |
Error | Error handling is a generic way to handle errors without losing data or failing the Snap execution. You can handle the errors that the Snap might encounter while running the Pipeline by choosing one of the following options from the When errors occur list under the Views tab. The available options are:
Learn more about Error handling in Pipelines. |
Account
This Snap uses account references created on the Accounts page of SnapLogic Manager to handle access to this endpoint. This Snap supports a Basic auth account, an AWS S3 auth account, SSH Auth account, SMB account, or no account. See Configuring Binary Accounts for information on setting up accounts that work with this Snap. Account types supported by each protocol are as follows:
Protocol | Account types |
---|---|
sldb | no account |
s3 | AWS S3 |
ftp | Basic Auth |
sftp | Basic Auth, SSH Auth |
ftps | Basic Auth |
hdfs | no account |
http | no account |
https | no account |
smb | SMB |
wasb | Azure Storage |
wasbs | Azure Storage |
gs | Google Storage |
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 S3 | Access-key ID, Secret key |
SSH Auth | Username, Private key, Key Passphrase |
SMB | Domain, Username, Password |
Azure Storage | Account name, Primary access key |
Google Storage | Approval prompt, Application scope, Auto-refresh token (Read-only properties are Access token, Refresh token, Access token expiration, OAuth2 Endpoint, OAuth2 token and Access type.) |
Snap Settings
Asterisk (*): Indicates a mandatory field.
Suggestion icon (): Indicates a list that is dynamically populated based on the configuration.
Expression icon ( ): Indicates whether the value is an expression (if enabled) or a static value (if disabled). Learn more about Using Expressions in SnapLogic.
Add icon ( ): Indicates that you can add fields in the fieldset.
Remove icon (): Indicates that you can remove fields from the fieldset.
Field Name | Field Type | Description | ||
---|---|---|---|---|
Label* Default Value: Multi File Reader | String | Specify 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. | ||
Selected Files | Use this field set to define data sources. All selected files must be under the same protocol. | |||
Folder/File Default Value: [None] Example:
| String/Expression | Specify the URL for the data source, which can be a directory or a file. It should begin with a file protocol. The supported file protocols are:
This Snap supports S3 Virtual Private Cloud (VPC) endpoint. For example, s3://my-bucket@bucket.vpce-028b7814794578709-vu0vvauy.s3.us-west-2.vpce.amazonaws.com The File property should have the syntax: [protocol]://[host][:port]/[path]
"://" 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.
In the SnapLogic 4.3.2 release, WASB (Windows Azure Storage Blob) or WASBS protocol (wasb:/// or wasbs:///) support has been added to the Binary Snaps.
| ||
Wildcard Default Value: [None]
| String/Expression | Specify the wildcard pattern, if the URL in the Folder/File property is for a directory. All files matching the wildcard pattern are selected. This property is not supported for the sldb, http, and https protocols. The asterisk pattern character ("*", also called "star") and the question mark ("?") are supported. The "*" character matches zero or more characters. The "?" matches exactly one character. | ||
Include Subfolders Default Value: Not selected | Checkbox | Select to search subfolders for the specified Wildcard if Folder/File is set to a directory. If you select this checkbox and the Folder/File property is a folder, all files in the subfolders matching the given wildcard pattern are selected. This checkbox is not supported for the sldb, http, and https protocols. | ||
Number of retries Default Value: 0 | Integer/Expression | Specify the maximum number of retry attempts the Snap must make in case there is a network failure, and the Snap is unable to read the target file. If the value is larger than 0, the Snap first downloads the target file to a temporary local file. If any error occurs during the download, the Snap waits for the time specified in the Retry interval and attempts to download the file again from the beginning. When the download is successful, the Snap starts to stream the data from the temporary file to the downstream pipeline. All temporary local files are deleted when they are no longer needed.
Minimum value: 0 | ||
Retry interval (seconds) Default value: 1 | Integer/Expression | Specify the minimum number of seconds for which the Snap must wait before attempting recovery from a network failure. Minimum value: 1 | ||
Advanced Properties | Use this field set to define additional properties. | |||
SAS URI | Dropdown list | Specify the URI of the Shared Access Storage (SAS) you need to access. You can generate the SAS URI either from the SAS Generator Snap or from the Azure portal → Shared access signature. The supported SAS types are:
Example: https://myaccount.blob.core.windows.net/sascontainer/sasblob.txt?sv=2015-04-05&st=2015-04- If the SAS URI value is provided in the Snap settings, then the settings provided in the account (if any account is attached) are ignored. | ||
Values | String/Expression | Specify the value for the property. | ||
Snap Execution | Dropdown list | Select one of the three modes in which the Snap executes. Available options are:
|
Output Fields for the Different Protocols
The output fields that the Multi File Reader Snap generates depends on the protocol you select. The following table lists the output fields for the different protocols supported by the Snap:
Protocol | Output Fields |
---|---|
S3 |
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SLDB |
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|
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