#throttling 6 articles
A column called MyField0 appears — a throttled existence check or two web parts provisioning at once gotchas / rest-api POST /fields with a taken name succeeds with a numeric suffix; 429 read as "missing", a cached check or two concurrent web parts each make a twin — three-state check, single run per site, name check after the create A throttled permission probe must not downgrade — and cache — the role gotchas / rest-api A 429/403 on currentuser/groups resolves to the lowest role; cache it and the user is stuck read-only for the TTL; only persist a confirmed (200) result Retrying a throttled call is safe for GET only gotchas / rest-api 429 means "not now", not "nothing happened"; no idempotency key exists, so a retried write duplicates the row (+ RateLimit-* headers are not guaranteed for delegated calls) Search REST returns 500 "unknown error" and 429 "low resources" for minutes at a time — retry the read, don't fix the query gotchas / search SharePoint Search REST can fail for a few minutes with HTTP 500 SearchServiceException (no Retry-After) and HTTP 429 low-resources errors; the same query succeeds seconds later, so retry reads briefly with a fixed… Title and Created are the fields you filter on — and the ones your provisioning code never indexes gotchas / lists Provisioning indexes only the columns it creates, so the most-filtered fields stay unindexed; past 5,000 items the read throttles and a swallowed error in a write path stops all writes silently Unbounded Promise.all fan-out over a customer-sized collection invites HTTP 429 gotchas / rest-api Fan-out is safe when YOUR code decides the count, dangerous when the customer's data does; bounded batch and worker-pool patterns