"Concept ID" is the unique identified assigned, by the CMR, to each of its holdings, Collections, Granules, etc. By convention, the ID indicates the type of concept by the first character: 'C' - Collection, 'G' - Granule, etc. So, in your case, a granule search, constrained to a specific CMR Collection, would more accurately specify the 'collection_concept_id' of the search space, as no granule would, itself, have a concept id of 'C*'. The CMR assumes your intent, however, and interprets the indicated concept_id as collection_concept_id, based on the naming convention. It's simply more accurate, and less prone to possible confusion or error, to scope the granule query to a collection via 'collection_concept_id'.
See: https://cmr.earthdata.nasa.gov/search/s ... h/api.html
, Find all granules for a collection.
No, there is no defined limit on the concurrent number of queries initiated from a single client source. We want to be flexible to support the client's needs, while monitoring the system for any issues.
The system is designed and provisioned in order to accommodate the need for clients to define their request rate as required, subject to overall performance considerations. Naturally there are finite resources available to the platform and services, and performance and stability of the entire system may be degraded for all users if the system were to be placed under "excessive" load for long periods of time.
How many concurrent threads are wanting to be able to use? You said "hundreds"...can you be more specific?
What is your expected or measured rate of overall queries per sec/min/hour?
Do you have an acceptable error rate?
Do you have an acceptable search latency per request (average and/or 95th percentile)?
Do you supply a Client-ID in the header of your search requests? While the Client ID is not required, it is helpful and we encourage its use. If you haven't done so, please reference the https://wiki.earthdata.nasa.gov/display ... -Client-Id
which describes its use and usefulness:
Client-Id is an additional header that allows the client to specify their name. Client Partners are strongly encouraged to use this header for the following reasons:
Helps the CMR operations team monitor query performance per client
Aids the CMR operations team in identifying clients who are attempting to contact them for assistance with a request.
Facilitates NASA in collecting information on how much traffic flows through a client provider and what kind of data interests their users.
Note this value is provided as part of the header for each request.
curl -v -H "Client-Id: Client Partner Name" -i https://cmr.uat.earthdata.nasa.gov/search/collections
If you are already providing the Client-Id, I can use it to examine your search history to quantify the volume and error-rate of use.