Frequently Asked Questions

Zero Downtime Migration (ZDM) means the ability for you to reliably migrate client applications and data between CQL clusters with no interruption of service.

ZDM lets you accomplish migrations without the need to change your client application code, and with only minimal configuration changes. While in some cases you may need to make some minor changes at the client application level, these changes will be minimal and non-invasive, especially if your client application uses an externalized property configuration for contact points.

The suite of ZDM tools enables you to migrate the real-time activity generated by your client applications, as well as transfer your existing data, always with a simple rollback strategy that does not require any downtime.

It is important to note that the Zero Downtime Migration process requires you to be able to perform rolling restarts of your client applications during the migration.

Here’s a high-level view:

Here are the phases of a migration from start to finish:

For more, see Introduction to Zero Downtime Migration.

DataStax Zero Downtime Migration includes the following:

ZDM Proxy is a component designed to seamlessly handle the real-time client application activity while a migration is in progress. See here for an overview.

Migrating client applications between clusters is a need that arises in many scenarios. For example, you may want to:

Bottom line: You want to migrate your critical database infrastructure without risk or concern that your users' experiences will be affected.

Overall, you can use ZDM Proxy to migrate:

Here are just a few examples of migration scenarios that are supported when moving from one type of CQL-based database to another:

Before DataStax Zero Downtime Migration was available, migrating client applications between clusters involved granular and intrusive client application code changes, extensive migration preparation, and a window of downtime to the client application’s end users.

ZDM allows you to leverage mature migration tools that have been used with large scale enterprises and applications to make migrations easy and transparent to end users.

The suite of Zero Downtime Migration tools from DataStax is free and open-sourced.

If needed, ZDM Proxy and related software tools in the migration suite include technical assistance by DataStax Support.

For any observed problems with the ZDM Proxy, submit a GitHub Issue in the ZDM Proxy GitHub repo.

Additional examples serve as templates, from which you can learn about migrations. DataStax does not assume responsibility for making the templates work for specific use cases.

All the DataStax Zero Downtime Migration GitHub repos are public. You are welcome to read the source and submit feedback via GitHub Issues per repo.

Yes, and here’s a summary:

For TLS details, see Configure Transport Layer Security (TLS).

When moving your client applications and data from on-premise Cassandra Query Language (CQL) based data stores (Cassandra or DSE) to a cloud-native database (CNDB) like Astra DB, it’s important to acknowledge the fundamental differences ahead. With on-premise infrastructure, of course, you have total control of the datacenter’s physical infrastructure, software configurations, and your custom procedures. At the same time, with on-premise clusters you take on the cost of infrastructure resources, maintenance, operations, and personnel.

Ranging from large enterprises to small teams, IT managers, operators, and developers are realizing that the Total Cost of Ownership (TCO) with cloud solutions is much lower than continuing to run on-prem physical data centers.

A CNDB like Astra DB is a different environment. Running on proven cloud providers like AWS, Google Cloud, and Azure, Astra DB greatly reduces complexity and increases convenience by surfacing a subset of configurable settings, providing a well-designed UI known as Astra Portal, and a set of APIs to interact programmatically with your Astra DB organizations and databases.