Transaction Limits

[Yitzhak Magoon]

Are there transaction limits to the number of times you can hit FHIR endpoints? If I pull 40k patients from a bulk load and need to hit additional resources for each patient, can I just send 100k+ transactions or do they need to be spaced out? 

[Aaron McGinn (Oracle Cerner)]

There are transaction limits that will cause 429 errors if this occurs. The limit can be different at each client. Our guidance is to have no more than 8 concurrent transactions at any given time. This reduces the server load and avoids needing to retry requests.

For bulk, it does not require requests to every resource for every patient. See our documentation [1] for more details.

[1] https://fhir.cerner.com/millennium/bulk-data/

-Aaron (Oracle Cerner)

[Yitzhak Magoon]

To clarify my question - say we use bulk to pull 20k patients, but the content of the request is not everything we need (e.g. coverage information, appointments, etc). We would need to call each of these resources for each patient (2 resources 20k patients = 40k calls). 

Just trying to figure out the best way to architect this to not overwhelm the servers and hit transaction limits, especially if every client can be different. 

[Aaron McGinn (Oracle Cerner)]

A bulk request would begin with a single request. All 20k patients' information would be processed together across resources. You would then query the status of the request and pull the results once the processing had completed. You should configure your app to pull all of the necessary information in the bulk request.

https://fhir.cerner.com/millennium/bulk-data/group-export/

-Aaron (Oracle Cerner)