I found that if the ranges in the list is too close may cause the isochrones request becomes very very slow.
Good case:
It takes less than 1 second.
curl -X POST \
'https://api.openrouteservice.org/v2/isochrones/cycling-regular' \
-H 'Content-Type: application/json; charset=utf-8' \
-H 'Accept: application/json, application/geo+json, application/gpx+xml, img/png; charset=utf-8' \
-H 'Authorization: XXX' \
-d '{"locations":[[120.59444062859512,24.154027643310602]],"range":[15709.283,18851.139,19851.139],"range_type":"distance"}'
Slow case:
It takes 17 seconds.
curl -X POST \
'https://api.openrouteservice.org/v2/isochrones/cycling-regular' \
-H 'Content-Type: application/json; charset=utf-8' \
-H 'Accept: application/json, application/geo+json, application/gpx+xml, img/png; charset=utf-8' \
-H 'Authorization: XXX \
-d '{"locations":[[120.59444062859512,24.154027643310602]],"range":[15709.283,18851.139,19751.139],"range_type":"distance"}'
The only different is the range parameter:
Good case: [15709.283,18851.139,19851.139]
Slow case: [15709.283,18851.139,19751.139]
It seems that if the range is too close (in this case, less than 100 metres between the ranges) will cause the request becomes very slow.
Originally it works. However we found it becomes slow after 2020/12.
Is there any constraint of isochrones API?