What do you do if your database migration project fails and all your data is at risk?

In many ways cutting over to new database after parallel runs is a better strategy than a big bang cutover. That will alleviate the risks in data migration projects totally. People have weird reasons including cost , time, effort as the reason to not parallel run. I think that is worth the insurance premium to avoid any data migration failure related losses

Backup strategy is something you should plan before migrating. Be prepared for it so that if you undertake a big project, you are also ready for potential big failures.

When a database migration project fails, the initial step is to evaluate the extent of the issue. This includes assessing data integrity, identifying failed migration segments, and gauging the impact on system performance. If there’s a backup strategy, ensure backups are viable. This assessment provides clarity on the situation and aids in devising a recovery plan to restore data and system functionality.

Project Data often supports organisation who are encountering issues with migrations. Skilled SMEs and adequate project management would see a swift and methodical approach to mitigate the situation. Assess & Isolating: Identify the root cause. Was it due to a technical glitch, misconfiguration, or other. Isolate the affected systems to prevent further damage. Infrastructure restore or backups: If you have recent backups, restore the database to the state before the migration. Rollback the Migration: If the migration process is reversible, roll back to the previous state. Engage Experts: Involve experts such as DBAs, Devs, and data SMEs Data Recovery: If data loss has occurred, explore data recovery Communication: Inform stakeholders

When performing a migration I always have a backup strategy in place so that there is little disruption in system performance if the migration fails. This means continuing to run the 'old' processes in parallel behind the scenes until.you have performed all post migration validation. Have a testing strategy and a post migration checklist that can help you identify if something does not migration properly. Plan how you will back out of the migration and fall back to using the old database if something goes wrong and the migration cannot be completed.

Remember to always have documentation even for simple everyday tasks. In case of a disaster, your mind could get stuck so that time won't be for to do search. Be prepared for that.

In my experience, having a back out or roll back plan can never be taken for granted. So, before starting the database migration, I would ensure that a current backup is taken and verified to be restorable to avoid the risk of losing the system and data. Therefore, if the migration fails, the natural course of action would be to restore from the backup data and validate the accuracy and completeness of the restore. This would be followed by a review of the reason for the failed migration with a view to addressing it and retrying the migration process.

After assessing the damage, the next step is to promptly initiate the restoration process from backups. Verify that the backups are recent and encompass all essential data before proceeding. Having a comprehensive backup and recovery strategy, which involves regular backups and test restores, is vital for minimizing downtime and data loss. If backups are compromised, explore alternative recovery methods like point-in-time recovery if supported by your system.

Keep your backup files in different places. Once our production server crashed and we lost the whole server and storages. Fortunately, I had my backup files on a second server and another copy on tape.

If possible, restore data from a backup taken before the migration attempt. This step requires caution to avoid overwriting any new data or creating data inconsistencies.

You can simulate the situation after the incident to reassess yourself with preparation. Would it be possible to react better if you knew something? It helps you to make a progress day after day.

I usually plan the migration and do it on a similar test server to find out if there is any problems. In this case I know the problem before putting my production data in risk and I am one step ahead of the imposed scenario here.

After ensuring your data's security, dedicate time to analyze the reasons behind the migration failure. Review logs, system reports, and error messages generated during the process. Understanding the failure's causes is crucial for averting similar issues in future migrations. It could stem from flaws in the migration script, unexpected data formats, or hardware incompatibilities. Pinpointing the root cause will guide adjustments to your migration plan.

Usually there are others with the same problems. Use their experience to get to the solutions faster and save time. I had colleagues spent a lot of time to find a problem and the relevant solution which was right in the first result of google search.

In the event of a failed database migration and data risk, fast action is very important . Immediately stop the migration process, assess the situation, and prioritize data recovery measures. Use backups and rollback procedures to restore data integrity and minimize potential loss. Consider using incremental migration methods and maintain backup and disaster recovery procedures. Test migration and rollback processes rigorously to ensure they work as expected It is also very important to document the process in case of next time and execute it on a pre-production database environment. it's crucial to plan and test very well, ensuring extensive data validation and quality checks.

With insights into the failure's causes, you can begin crafting your recovery plan. This may entail refining migration scripts, upgrading hardware, or adjusting data formats for compatibility. It's crucial to test these alterations in a controlled setting before executing another migration. The aim is to devise a resilient migration plan that tackles past failure points and guarantees a seamless transition.

To prevent database migration failures, it's crucial to plan and test thoroughly, ensuring extensive data validation and quality checks. Consider using incremental migration methods and maintain backup and disaster recovery procedures. Test migration and rollback processes rigorously to ensure they work as expected. Also, document the entire process and execute it on a pre-production database environment.

Once you've finalized your revised plan, start implementing the required fixes. This may involve modifying your database schema, rewriting sections of your code, or enhancing infrastructure reliability. Regardless of the solution, proceed cautiously and closely monitor the changes. A phased approach can be advantageous, migrating smaller data sets initially to validate the fixes before progressing to larger batches.

Once the immediate risks are mitigated, apply necessary fixes to prevent similar issues in the future. This may involve updating migration scripts, improving backup strategies, or enhancing system redundancy.

After implementing the fixes and restarting the migration process, meticulous monitoring is crucial. Monitor system performance, data integrity, and any potential errors closely. Continuous monitoring enables prompt resolution of new issues and adjustment of your strategy as required. Documenting the entire process is also essential for future reference and for enhancing your migration procedures in subsequent endeavors.

At this point, you should feed your mind with new things to ponder and research. Be adventurous in discovering what is new or which challenges you will address.

Encourage feedback from team members involved in the migration process to identify areas for improvement and ensure that lessons learned are incorporated into future projects.

I would like to say my data is NEVER at risk. I never "roll the dice" on my data. In my opinion, losing data is the most unforgivable sin in a migration of any kind. If a migration doesn't work, then we just drop back to what worked yesterday. Alive to migrate another day.