Updating database configuration
You can change the configuration of a Redis Enterprise Software database at any time.
To edit the configuration of a database:
- Click the relevant database row on the Databases page. The selected database page appears.
- Select the Configuration tab.
- Click Edit at the bottom of the page.
- The database settings appear. You can edit any of the configurable parameters. For explanation, refer to Creating a new database.
- Click Update.
Updating CRDB configuration
A Conflict-Free Replicated Database (CRDB) is a global database that spans multiple Redis Enterprise clusters called Participating Clusters and is made up of individual database instances. When creating a new CRDB you must configure which Participating Clusters are to host instances of the CRDB. However when updating database configurations with CRDB, most database settings only apply to the local CRDB instance configuration. Changes done to "Memory limit", "Data persistence", "Redis password", "Number of Shards", or "TLS Mode" and "Periodic backup" are only applied to the local CRDB instance and not applied to all Participating Clusters.
If the CRDB topology needs to change, you can add and remove Participating Clusters of a CRDB. Use the Participating Clusters list to manage the changes to CRDB topology in the UI. You can make one or more changes at any one time to the Participating Cluster list. The changes you make to the list are committed when the database configuration is saved.
When adding new Participating Clusters, a CRDB requires that all existing participating clusters are online and in a syncing state. If you need to remove one or more offline Participating Clusters, all remaining Participating Clusters need to be online and in a syncing state.
After any new Participating Clusters are added to an existing CRDB, the new CRDB instance does allow connections and read operations, however it does not allow write operations until it catches up to the syncing state.
It is recommended that removals are done when all Participating Clusters of the CRDB are online. However it is possible to remove offline Participating Clusters using forced removal. Participating Cluster removed forcefully may later resurrect back to life. However the forcefully removed Participating Cluster are shown as out of date on CRDB membership. Even though, it still thinks it is part of the CRDB. After a Participating Cluster is removed, all updates received by remaining CRDB Instances from the removed CRDB instance, are rejected.
TLS Authentication and Encryption
To prevent unauthorized access to your data, you can configure RS to secure communications with TLS protocol (the more secure successor to SSL). When you create CRDBs, you can specify TLS in two ways:
- Require TLS for All Communications - This configures the CRDB to support TLS for both data access operations performed on the database as well as inter-cluster CRDB communications.
- Require TLS for CRDB Communications Only - This configures the CRDB to support TLS for only inter-cluster CRDB communications.