OpenStack Swift Object Store - Technical Preview - Import - 7.1

Talend Data Catalog Bridges

author
Talend Documentation Team
EnrichVersion
7.1
EnrichProdName
Talend Big Data Platform
Talend Data Fabric
Talend Data Management Platform
Talend Data Services Platform
Talend MDM Platform
Talend Real-Time Big Data Platform
EnrichPlatform
Talend Data Catalog

Bridge Specifications

Vendor OpenStack
Tool Name Swift Object Store
Tool Version 1.0
Tool Web Site https://www.openstack.org/software/releases/queens/components/swift
Supported Methodology [File System] Multi-Model, Data Store (NoSQL / Hierarchical) via REST API
Data Profiling
Multi-Model Harvesting
Incremental Harvesting
Remote Repository Browsing for Model Selection

SPECIFICATIONS
Tool: OpenStack Swift Object Store version 1.0 via REST API
See https://www.openstack.org/software/releases/queens/components/swift
Metadata: [File System] Multi-Model, Data Store (NoSQL / Hierarchical)
Bridge: OpenStackSwift version 11.0.0

OVERVIEW
This bridge crawls a data lake implemented on a OpenStack Swift to detect (reverse engineer) metadata from all the data files (for data catalog purpose).

SUPPORTED FILES

This bridge supports the following file formats:
- Delimited (Flat) files such as CSV (see details below)
- Positional (Fixed Length) files typically from mainframe (see details below)
- COBOL COPYBOOK files typically from mainframe (see details below)
- Open Office Excel XML .XSLX (see details below)
- W3C XML
- JSON (JavaScript Object Notation)
- Apache Avro
- Apache Parquet
- Apache ORC

as well as the compressed versions of the above formats:
- ZIP (as a compression format, not as archive format)
- BZIP
- GZIP
- LZ4
- Snappy (as standard Snappy format, not as Hadoop native Snappy format)

DELIMITED FILES

This bridge detects (reverse engineer) the metadata from a data file of type Delimited File (also known as Flat File).
The detection of such Delimited File is not based on file extensions (such as .CSV, .PSV) but rather by sampling the file content.

The bridge can detect a header row, and use it to create the field name, otherwise generic filed names are created.

The bridge samples up to 1000 rows in order to automatically detect the field separators which by default include:
', (comma)' , '; (semicolon)', ': (colon)', '\t (tab)', '| (pipe)', '0x1 (ctrl+A)'
More separators can be added in the auto detection process (including double characters), see the Miscellaneous parameter.

During the sampling, the bridge also detects the file data types, such as DATE, NUMBER, STRING.

POSITIONAL FILES

This bridge creates metadata for data files of type Positional File (also known as Fixed Length File).
Such metadata cannot be automatically detected (reverse engineered) by sampling the data files (e.g. customers.dat or even just customers with no extension).
Therefore, this bridge imports a 'Positional File Definition' file which must be with extension .positional_file_definition format file
(e.g. customers.dat.positional_file_definition format file will create the metadata of a file named file customers with the fields defined inside)
This is the equivalent of a RDBMS DDL for positional files. With such a long extension, this data definition file can coexist with the actual data files in the each file system directory containing them.

The 'Positional File Definition' file format is defined as follows:
- Format file must start with the following header:
column name, position, width, data type, comment
- All positions must be unique and greater than or equal to 1.
a,1
b,5
- The file format is invalid when some columns have positions and others don't.
a,1
b,
c,5
- When all columns do not have positions but have widths the application assumes that columns are ordered and calculates positions based on widths.
a,,4 -> a,1,4
b,,25 -> b,5,25
- When the position is present the application uses widths for documentation only.
a,1,4
b,5,25
- Types and comments are used as documentation only.
a,1,4,int
b,5,25,char[25],identifier

COBOL COPYBOOK FILES

This bridge can only import the COBOL COPYBOOK files (which contain the data definitions), therefore does not detect (reverse engineer) metadata from actual COBOL data files.
The detection of such COBOL COPYBOOK File is not based on file extensions (such as .CPY) but rather by sampling the file content.

This bridges creates a 'Physical Hierarchical Model' which reflects a truly flat, byte-position defined, record structure, which is useful for stitching to the DI/ETL processes. Therefore, the physical model has all the physical elements required to define a flat record, which is ONE table with all the elements (including multiple columns for OCCURS elements when the proper bridge parameter is set).

Note that this bridge does not currently support the COPY verb, and reports a parsing error at the line and position at which the COPY statement begins. In order to import Copybooks with the Copy Statement, create an expanded Copybook file with the included sections already in place (replacing the COPY verb). Most COBOL compilers have the option to output only the preprocessed Copybooks with the COPY and REPLACE statements expanded.

Frequently Asked Questions:
Q: Why is the default start column '6' (six) and the default end column '72' (seventy-two)?
A: The bridge parser counts columns starting at 0 (zero), rather than 1 (one). Thus, the defaults leave the standard first six columns for line numbers, next column for comment indicators, and last 8 columns (out of 80) for additional line comment information.

EXCEL (XLSX) FILES

This bridge detects (reverse engineer) the metadata from a data file of type Excel XML format (XLSX).
The detection of such Excel File is based on file extension .XLSX.

The bridge can detect a header row, and use it to create the field name, otherwise generic filed names are created.

The bridge samples up to 1000 rows to detect the file data types, such as DATE, NUMBER, STRING.

If an Excel file has multiple sheets, each sheet is imported as the equivalent of a file/table with the same sheet name.

The bridge uses the machine's local to read files and allows you to specify the character set encoding files use.

MORE INFORMATION

Please refer to the individual parameter's tool tips for more detailed examples.


Bridge Parameters

Parameter Name Description Type Values Default Scope
REST Endpoint: Your REST Endpoint to sign programmatic requests to the service. STRING      
Auth V1 Endpoint: Your Auth V1 Endpoint to authenticate the bridge. STRING      
User User name STRING      
Password Password PASSWORD      
Container CONTAINER name STRING      
Miscellaneous Specify miscellaneous options identified with a -option followed by a value if required:

GENERAL OPTIONS
-m <Java Memory's maximum size>
1G by default on 64bits JRE or as set in conf/conf.properties, e.g.
-m 8G
-m 2500M

-j <Java Runtime Environment command line options>
This option must be the last one in the Miscellaneous parameter as all the text after -j is passed "as is" to the JRE, e.g.
-j -Dname=value -Xms1G

-jre <Java Runtime Environment full path name>
It can be an absolute path to javaw.exe on Windows or a link/script path on Linux, e.g.
-jre "c:\Program Files\Java\jre1.8.0_211\bin\javaw.exe"

-v <Environment variable value>
None by default, e.g.
-v var1=value1 -v var2="value2 with spaces"

-model.name <model name>
Override the model name, e.g.
-model.name "My Model Name"

-prescript <script name>
The script must be located in the bin directory, and have .bat or .sh extension.
The script path must not include any parent directory symbol (..).
The script should return exit code 0 to indicate success, or another value to indicate failure.
For example:
-prescript \"script.bat\"

FILE SYSTEM OPTIONS
-tps <Processing Thread Pool Size's maximum count>
By default 1, for e.g.
-tps 10

-tl <Processing Time Limit duration>
No limits by default. Time can be specified in seconds, minutes, or hours, e.g.
-tl 3600s
-tl 60m
-tl 1h

-fl <Processing File Limit count>
No limits by default, e.g.
-fl 100

-hadoop <Hadoop configuration options>
None by default, e.g.
-hadoop key1=val1;key2=val2

-fresh.partition.models
Use to import latest modified files when processing partitions defined in Partitioned directories parameter.

-subst <path> <new path>
Use to associate a root path part with a drive or another path, e.g.
-subst K: C:/test

-skip.download
Use to disable dependencies downloading and use only download cache

-disable.partitions.autodetection
Use this option to disable automatic partitions detection(when "Partition directories" option is empty)

DELIMITED FILE OPTIONS
-delimited.no_header
Delimited File's header by default, bridge automatically tries to detect headers while processing csv files(basing on header columns types), use this option to disable headers import(f.e. to hide sensitive data)

-delimited.top_rows_skip <number>
Delimited file's number of rows to skip while processing (0 by default), e.g.
-delimited.top_rows_skip 1

-delimited.extra_separators <comma separated separators>
Delimited file's extra delimiters (separators by default are ), e.g.
-delimited.extra_separators ~,||,|~

PARQUET FILE OPTIONS
-parquet.compressed.max.size=<value>
Ignore parquet archives with size bigger then defined with this option value (Default value is 10 000 000 bytes), e.g.
-parquet.compressed.max.size=10000000
STRING      

 

Bridge Mapping

Meta Integration Repository (MIR)
Metamodel
(based on the OMG CWM standard)
"OpenStack Swift Object Store - New Beta Bridge"
Metamodel
File System (File)
Mapping Comments
     
Attribute Array Elementary Item, Field, Attribute, Array Field, Elementary Item, Fixed Width Field, Partition Field  
Name Name  
Position Position, Offset  
Class Array Element, Group Item, Array Group Item, Array Object, Element, Object, Sheet  
Name Name  
PropertyElementTypeScope UDPs  
Name Name  
Scope Scope  
PropertyType UDP  
DataType Data Type  
DesignLevel Design Level  
Name Name  
Position Position  
StoreModel Cobol File, Parquet File, Delimited File, Avro File, Json File, Collection, Orc File, Xml File, Excel File, File, Fixed Width File  
Name Name  
TypeValue Condition Name  
Name Name  
Value Value