Instana enforces a default rate limit on its Web REST API to ensure service stability and fair usage across all tenants. This limit is set at 5,000 calls per hour for each individual API token. When an API call is made, Instana checks the usage associated with the token provided in the Authorization header. If the number of calls exceeds this limit within the hour, subsequent requests will be rejected with an HTTP 429 Too Many Requests status code until the rate limit window resets.

A. 10,000: This value is incorrect; the default hourly limit is half of this amount.

C. 6,000: This is not the specified default rate limit in the official Instana documentation.

D. 1,000: This value is significantly lower than the actual default limit of 5,000 calls per hour.

1. IBM Documentation for Instana Observability. "Web REST API". Section: Rate Limiting. The documentation states, "The rate limit for API calls is 5000 calls per hour per API token." This is the primary source defining the default value.