This is part 2 of 4 in a series of articles with information about migrating Databricks projects from Compose for Data Lakes 6.6 (C4DL 6.6) to Qlik Compose 2021.8 (Gen2)
Different Migration Modules for customers
- Migration Pre-Requisites
- Hive to Hive supported version
- Spark to Spark supported version
Module 2: Migrate Databricks projects from C4DL 6.6 to Gen2
In C4DL 6.6, we have only option to create ODS project and Gen2 we can also create HDS, you can decide now to change the project type in Gen2. Please reach out to support if you have any questions.
There are two paths for data bricks ODS project, you can choose one of the paths to finish migration:
Path 1: You can clean up storage database and replicate landing database (including underlaying files for attrep_cdc_partition). Reload replicate task and start the compose tasks as it is new project. It was covered in first demo.
Path 2: You can follow migration path, and I explained all the required steps in this document.
Here are the migration steps (Path 2) if you don’t want to reload the replicate task. You are going to completely migrate your project definition and data to Gen2.
- Install Qlik Compose 2021.8 on a dedicated machine\the same machine where FDL 6.6 exist.
- Select a project in C4DL 6.6 and run the CDC task last time with verbose.
- Create the deployment package - Suresh_Databricks_deployment_<datetime>.zip
- Run the CDC task last time before migrate data and disable if there are any schedules on the tasks.
- Create new project in 2021.8 with the same name and project type as it is in FDL 6.6. you have to migrate data also so create new a storage database with different name (we can’t use same database which is using in C4DL project) and provide it in Data Lake connection. Do the test connection to make sure you have correct drivers installed for your data lake. Now we have an empty project in gen2 with storage connection.
- Deploy the projects on Qlik Compose 2021.8 and migrate the data
- Migrate the project definitions
- Login to Qlik Compose 2021.8 cli and run below command to create compatible package.
ComposeCli.exe adjust_cfdl_project --project Suresh_Databricks_ODS --infile “C:\Program Files\Qlik\C4DL66\Suresh_Databricks_ODS_deployment_<datetime>.zip”
à C:\Program Files\Qlik\Compose\data\projects\Suresh_Databricks_ODS\deployment_package \Suresh_Databricks_ODS__<datetime>__QlikComposeDLMigration.zip
- Deploy adjusted deployment package on gen2 project.
- Validate model and create the storage tables.
- Generate tasks then execute a data migration SQL script from notebook.
- Generate 'create data migration script’ using below cli (Qlik Compose 2021.8 cli) command and run it on storage database from Notebook.
ComposeCli.exe create_cfdl_data_migration_script --project Suresh_Databricks_ODS --infile “C:\Program Files\Qlik\C4DL66\Suresh_Databricks_ODS_deployment_<datetime>.zip”
- verify the data is correct
NOTE:
- We must use new storage database in path 2 because we are going to run select * from C4DL 6.6 storage database and insert into Qlik Compose 2021.8 storage database in the migrate data step (3 (b)).
- If you want, you can run C4DL project and Gen2 project parallelly for few days.
After migration you can check\run
- ODS and HDS live views before running CDC
- CDC with updates\inserts\deletes
- CDC with reload event
- schema evolution - you should run schema evolution and skip all detected changes - to set the context
also set
- workflow
- scheduler
- notification
- work with multiple replicate servers
You can watch demo video How to Migrate Databricks ODS projects.
Environment
- From Compose for Data Lakes 6.6
- To Qlik Compose 2021.8
The information in this article is provided as-is and to be used at own discretion. Depending on tool(s) used, customization(s), and/or other factors ongoing support on the solution below may not be provided by Qlik Support.
Related Content
Migration paths for Qlik Compose
