The Résif data centre updates its fdsn-dataselect webservice to version 1.1.1
The main change concerns the evaluation of response sizes to dataselect requests.
When the user makes a request to obtain data with the dataselect webservice, the data centre must check that it can deliver the requested data in a reasonable time and without affecting the rest of the activity.
If the webservice estimates that the request will require too much data to be sent, then it returns the error code 413 with a “too much data” message to the user.
The evaluation of this limit was not very satisfactory, but it allowed to roughly filter out too large requests. In particular, it penalised requests short in duration but involving many channels.
We have implemented a new method to evaluate the size of the request taking into account for each requested trace its time interval and the sampling frequency of the concerned channels. The limit is expressed in number of measurement points (samples) and set to 10 billions, which corresponds to about 8GB of data. The evaluation does not take into account possible gaps in the time series.
We hope that this update (v1.1.1) will better meet users’ expectations.