Snapshot Priority — Snapshot-specific priority is a simple control that increases or decreases the frequency with which snapshot tasks are added to the queue. You control the snapshot priority by setting the deployment.systemsettings.snapshot.priority property as an integer value. The larger the value, the longer the interval between snapshot tasks.

Queue Priority — You can assign snapshots a priority for queueing the same way you can for other user and operational tasks. This means you set the priority relative to other activities such as XDCR, export, or user tasks. You can even set the priority for individual user transactions using the Client2 API. You set the queue priority for snapshots by assigning the deployment.systemsettings.priorities.snapshot.piority property an integer value between 1 and 8. Again, the higher the number, the lower the priority. Note the snapshot-specific priority and queue priority are mutually exclusive. If queue priorities are enabled, the snapshot-specific prioritization will be disabled.

Autotuning — Finally, you can choose to let the system select the best option for the frequency and size of snapshot tasks by enabling snapshot autotuning. Rather than setting fixed values, autotuning uses the current workload, measured as the size of the transaction queue, to decide how frequently to run snapshot tasks each time. The busier the queue, the less frequently snapshot tasks will run and the smaller the tasks will be. Resulting in slower snapshots but less impact on latency. On the other hand, because the adjustments are sensitive to the current queue size, when the workload is low the snapshot tasks can be larger and run more frequently. So snapshot performance is not negatively affected during lulls in the database workload. You enable autotuning by setting the deployment.systemsettings.snapshot.autotune.enabled property to true, which can be done either when configuring the database or on the fly while the database is running.