mssql_to_redshift_data_transfer_tool

MSSQL to AWS Redshift data transfer tool written in Python 3.7

• Introduction
• How this tool works
• How to install and run the tool
• How to setup a new MSSQL to Redshift data migration project

Introduction

This tool is able to migrate data from your MSSQL Database to AWS Redshift. It consumes arguments defining:

• --databasename or -dn ( the name of the database with the tables in MSSQL you wish to migrate over, this argument needs to be aligned with the values in the column DatabaseName inside the configuration table MSSQL_to_Redshift.mngmt.ControlTable )
• --schemaname or -sn ( the name of the database schema with the tables in MSSQL you wish to migrate over, this argument needs to be aligned with the values in the column SchemaName inside the configuration table MSSQL_to_Redshift.mngmt.ControlTable )
• --generated_csv_files_target_directory or -td ( the local folder where you wish to store your .csv files, if the folder not exists, it will be created for you during the runtime)
• --dryrun or -dr ( True | False allowed ,this argument let's you run a dry run for testing purposes, filtering SQL Server data to 0 rows)

How this tool works

How to install and run the tool

To install:

• git clone https://www.github.com/datahappy1/mssql_to_redshift_data_transfer_tool mssql_to_redshift_data_transfer_tool
• cd c:\mssql_to_redshift_data_transfer_tool
• create and activate a virtual environment
• download Windows Postgres Driver from https://www.enterprisedb.com/downloads/postgres-postgresql-downloads
• pip3 install -r requirements.txt
• run the database build script using mssql_database_buildscript.sql located here

Setup these environment variables:

• odbc_mssql_dsn_name - mandatory MSSQL DSN name for PyODBC
• odbc_mssql_uid - optional MSSQL DSN user name, not needed if you set the user in Windows ODBC connection
• odbc_mssql_pwd - optional MSSQL DSN password, not needed if you set the password in Windows ODBC connection
• aws_access_key_id -mandatory AWS Access key ID
• aws_secret_access_key -mandatory AWS Secret access key
• redshift_host -mandatory AWS Redshift host name ( for example redshift-cluster-1.xxx.us-east-1.redshift.amazonaws.com )
• redshift_port -mandatory AWS Redshift port ( integer )
• redshift_user -mandatory AWS Redshift user name
• redshift_pass -mandatory AWS Redshift password

First run on Windows:

You need to set the PYTHONPATH like this: set PYTHONPATH=%PYTHONPATH%;C:\mssql_to_redshift_data_transfer_tool\

A permanent solution is to:

1. Go to the Windows menu, right-click on “Computer” and select “Properties”
2. From the computer properties dialog, select “Advanced system settings” on the left
3. From the advanced system settings dialog, choose the “Environment variables” button
4. In the Environment variables dialog, click the “New” button in the top half of the dialog, to make a new user variable
5. Give the variable name as PYTHONPATH and the value is the path to the code directory. Choose OK and OK again to save this variable
6. Now open a cmd Window (Windows key, then type cmd and press Return). Type: echo %PYTHONPATH% to confirm the environment variable is correctly set

https://bic-berkeley.github.io/psych-214-fall-2016/using_pythonpath.html

First run on Linux:

You need to set the PYTHONPATH like this: export PYTHONPATH=$PYTHONPATH:/home/your_user/your_git_projects/mssql_to_redshift_data_transfer_tool/

A permanent solution is to:

1. Open your favorite terminal program
2. Open the file ~/.bashrc in your text editor – e.g. atom ~/.bashrc
3. Add the following line to the end: export PYTHONPATH=/home/my_user/code
4. Save the file
5. Close your terminal application
6. Start your terminal application again, to read in the new settings, and type this: echo $PYTHONPATH , you should see something like /home/my_user/code

To run:

You need to set the required arguments :

• --databasename or -dn
• --schemaname or -sn
• --generated_csv_files_target_directory or td
• --dryrun or -dr

Run these commands to execute:

1. cd mssql_to_redshift_data_transfer_tool
2. python mssql_to_redshift_data_transfer_tool.py -dn AdventureWorksDW2016 -sn dbo -td C:\mssql_to_redshift_data_transfer_tool\files -dr False

How to setup a new MSSQL to Redshift data migration project

1. Setup the database tables with their columns that you need to transfer over to AWS Redshift in the MSSQL Configuration table MSSQL_to_Redshift.mngmt.ControlTable

Note that this tool's internal database MSSQL_to_Redshift has to be installed at the same host where your source MSSQL databases are located. Another option is to use Linked Servers

2. Don't forget to setup the project-scoped settings like the AWS S3 bucket name, the maximum csv filesize in MB, database names, logging level and others using settings.py

Allowed logging level values in settings.py are 'DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL'

3. Make sure you've got your AWS Redshift tables ready

Redshift tables need to be named exactly like the tables configured in MSSQL_to_Redshift.mngmt.ControlTable MSSQL table

4. Set the Pythonpath env.variable
5. Try running this tool with the --Dryrun argument first set to true
6. Now you can go and configure the databases, schemas and table names that will be transferred over to AWS Redshift in the MSSQL_to_Redshift.mngmt.ControlTable MSSQL table