alamb opened a new issue, #800: URL: https://github.com/apache/arrow-rs-object-store/issues/800
**Is your feature request related to a problem or challenge? Please describe what you are trying to do.** Reported by @emilk on https://github.com/apache/arrow-rs-object-store/pull/781: `AzureClient::signer()` calls `get_user_delegation_key()` — a `GetUserDelegationKey` network round-trip (`POST /?restype=service&comp=userdelegationkey`) — on **every** `signed_url` / `signed_urls` call. A user delegation key is reusable until its expiry, so re-fetching it per request is wasteful and, under load, gets throttled by Azure (HTTP 503 `ServerBusy`). Notably the other backends do **not** make an uncached network call while signing: the AWS signer signs locally from its cached credential, and GCP caches its signing credentials. Azure is the outlier — it makes a `GetUserDelegationKey` call on top of the already-cached AAD token. We hit this in production: a workload issuing many presigned-URL requests against Azure Blob drove ~100k `GetUserDelegationKey` POSTs in 2h (~840/min), ~35% of which returned 503. The retry client backed off 10× (~10s) and then surfaced the error to the caller. **Describe the solution you'd like** <!-- A clear and concise description of what you want to happen. --> **Describe alternatives you've considered** <!-- A clear and concise description of any alternative solutions or features you've considered. --> **Additional context** <!-- Add any other context or screenshots about the feature request here. --> -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
