Cache invalidation
Document how to bypass the cache safely
The receiving team needs a way to inspect authoritative data and recover stale entries without turning a diagnostic action into a production outage.
In this article
Explain what each cache is for
List the browser, edge, process-local and shared caches used by the application. For each, identify the stored representation, key scope, expiry policy and source of truth.
Include the business reason for any permitted staleness. A future maintainer should know why a catalogue preview can lag while an order confirmation cannot.
Keep this inventory close to the service documentation. A diagram showing only the database and API leaves operators guessing when a response remains old after the database has changed.
Provide a controlled diagnostic path
Document how an authorised operator can compare a normal response with an authoritative read. Explain which layers the diagnostic path bypasses and which it still uses.
Restrict access and rate. An unrestricted bypass can become an expensive public endpoint that defeats the cache's protection of the source.
Return useful provenance such as revision and load time where appropriate, while avoiding unnecessary sensitive data. The goal is to identify the stale layer, not to create a second unrestricted reporting interface.
Make purge scope visible
Give examples of invalidating one resource, one tenant and a whole namespace. Show how the operator confirms the selected scope before running a broad action.
Explain the expected refill load and the controls that protect the source. A purge command that succeeds instantly may cause several minutes of expensive downstream work.
Include recovery from failed invalidation and from incorrect key construction. These are different incidents. Repeating a purge cannot fix a key that omits the caller's tenant or language.
Practise a stale-data investigation
Seed a synthetic outdated value in a non-production environment. Ask the receiving team to locate it, compare it with the source and repair the correct scope.
Then simulate an empty cache and observe source load. This verifies that the team understands the operational consequence of its recovery tools.
Record owners for the application policy and the cache infrastructure. The platform team may restore availability, while the application team must decide whether serving stale data is acceptable. Both responsibilities need a clear contact during an incident.
Primary sources
Microsoft: cache-aside patternReferences checked 11 September 2026.