Before integrating KijiScoring into your application, you'll want to spend some time on the system-wide design to make sure that freshening adds value and doesn't delay results unnecessarily. Here are some considerations:
As with any time-sensitive operation, you'll want to design your system to do as little as possible between the request and getting data to the application. For example, consider asynchronous processes to update the data to reduce the likelihood of triggering freshening. KijiScoring allows you to set a timeout value for each freshening: how long can the freshening process take before the read simply takes the existing stale value. You'll want to experiment to understand typical response times and determine what your application can tolerate in terms of waiting for refreshed data.
Freshening multiple columns in a single read request
KijiScoring allows you to specify if the freshened result needs to include refreshed values from all columns involved in the request, or if results for each column can be provided as they are available. Use Partial Freshening if your application uses the values from individual columns in the request results independently.
Per-request configuration information
Apply additional information to the scoring process beyond what's stored in the Kiji table.
Data read as input to the freshening process will not itself be freshened. This kind of cascading freshening would make it very difficult to guarantee desirable performance.
- Scoring Tutorial Overview
- KijiScoring Setup
- Freshness Policy
- Score Function
- Registering a FreshnessPolicy and ScoreFunction
- Accessing the Refreshed Data
- Next Steps