Number Ranges
The Redis storage and the configuration options for this have been introduced with Shopware version
Number Ranges provide a consistent way to generate a consecutive number sequence that is used for order numbers, invoice numbers, etc. The generation of the number ranges is an atomic operation, this guarantees that the generated sequence is consecutive and no number is generated twice.
By default, the number range states are stored in the database. In scenarios where a high throughput is required (e.g. thousands of orders per minute), the database can become a performance bottleneck, because of the requirement for atomicity. Redis offers better support for atomic increments than the database, therefore the number ranges should be stored in Redis in such scenarios.

Using Redis as storage

To use Redis, create a config/packages/shopware.yml file with the following content:
increment_storage: "Redis"
redis_url: 'redis://host:port/dbindex'

Migrating between storages

You can migrate the current state of the number ranges from your current storage to a new one by running the following CLI command:
bin/console number-range:migrate {fromStorage} {toStorage}
For example if ou want to migrate from the default SQL storage, to the high-performing Redis storage the command is:
bin/console number-range:migrate SQL Redis
If you want to migrate from or to Redis, please ensure that the shopware.number_range.redis_url is correctly configured, regardless if Redis is currently configured as the increment_storage.
Note that the migration of the number ranges between different storages is not atomic, this means that if you migrate the number ranges, and simultaneously new number increments are being generated this may lead to the same number being generated twice. Therefore, this command should normaly not run during normal operations of the shop, but rather during part of a deployment or maintenance.