Join attributes & policy
Join attributes to control and optimise performance
Last updated
Join attributes to control and optimise performance
Last updated
These attributes define how the join is performed with respect to the expression, how to create the emitted event structure etc.
Attribute | Description | Data Type | Required |
---|---|---|---|
Fine grained control can be applied to how joins are handled through the use of the policy attribute.
This becomes relevant for large and fast event stream with respect to memory and processing overhead.
Default configuration
delete on join is set to false and therefore will join events until the time to live setting is honoured.
time to live is set for 60 minutes per stored event. This is refreshed every time a new event is received with the same join attribute value.
Attribute | Description | Data Type | Required |
---|---|---|---|
expression
Simple join expression that evaluates two streams
String
merge events
Flag that either merge event attributes into a flattened event structure or places each event
Boolean Default: true
event type
User defined type of emitted event
String Default: left type - right type (i.e. typeA-typeB)
left / right join
See Join attribute section
Policy attribute Default
delete on join
Delete event from state management on a successful join
Boolean Default: false
time to live
Expire configuration for event stored within the state management system. Supported time units include nanoseconds, microseconds, milliseconds, seconds, hours and days
Formatted string Default: 60 minutes