Join us at ScyllaDB LIVE, instructor-led NoSQL training sessions | June 18
Register now

Service Level Options

7 min to complete

Service level – a session-specific configuration that defines some key aspects of the workload.
It is determined by the logged-in role and its hierarchy of inherited roles.
Allows for session tweaking on the administrative level (instead of the client application level).
Service level options: Workload type – one of interactive or batch
Timeout – the default timeout for the session
Scylla has a default timeout in the static configuration (scylla.yaml / command line options)
It also has a “USING TIMEOUT” syntax in CQL
The session timeout will be the default if “USING TIMEOUT” is not specified and will override the static configuration.
Workload type only exists as a session parameter (service level option)
“Hints” ScyllaDB about how to deal with overload.
For Interactive:
Drops request early with an overloaded exception
Prevents “Live Lock” (Little’s law)
Prevents starting a request that is likely to timeout (better system utilization)
For batch – higher tolerance for large queues since slow responses are a “Natural Throttling” due to the bounded concurrency and typically larger timeouts