Jaeger remote sampling: strategy file updates not picked up by clients after collector ConfigMap change

Remote sampling configuration scope

I am configuring centralized remote sampling for Jaeger, where client libraries poll the collector's /sampling endpoint for their strategy. The strategy is defined in a file mounted into the collector (via a ConfigMap in a Kubernetes/Operator deployment), and the goal is for all services to adopt updated per-service probabilistic rates without redeploying applications.

Observed uncertainty

Two constraints are unclear from the documentation. First, whether the collector reloads the strategy file when the underlying ConfigMap changes, or whether a collector restart is mandatory before new rates are served. Second, how strategy document versions interact: older and newer client libraries appear to expect different strategy formats, and it is not documented what a newer client does when the collector serves a format it does not recognize — whether it errors visibly or silently falls back to a default probabilistic rate.

Assume a collector in the 1.4x range with mixed client library versions across services; exact behavior may be version-dependent and needs verification against the collector's /sampling response.

Questions

• Does a strategy file change require a collector restart to take effect, and if so, is there any supported hot-reload mechanism?
• What is the defined client-side fallback when the served strategy document version is unsupported, and is it logged?
• In a mixed-version fleet, is there a recommended strategy format that all supported clients can parse?