In the MARS activity you can see only the requests that are currently "active" on the Web API level. A "queued" request is not visible in MARS activity.

You can use it for these reasons:
  1. It can give you a good insight of your current request status and of your request details (like number of fields, number of tapes accessed etc)
  2. It can give you a very good indication of why your request is slow
  3. It can provide you a lot of information that you need to improve the efficiency of your request like
    • how many tapes your request is accessing (in the MARS log output)
    • the reason why a requests is queued.
    • other users requests.

See Guidelines to write efficient MARS requests.

Other users requests

(lightbulb)Many requests submitted by other users may be running in parallel consuming the services resources (MARS slots, Web-API slots, Tapes access slots etc). These requests may be very useful  to understand the efficiency factors.

  • Compare the activity of your requests to the other users activity using the MARS activity page.
  • See the reason that some requests are "queued" and how long they have been "queued".
  • Have a look on the MARS logs about limitations like:
    • "In marsod-core, the total number of Requests from ECMWF Web API with 1 tape mount [source] is limited to 6"
    • etc