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Orbital drop requests are starved by other requests

Posted: Sat Oct 26, 2024 6:50 pm
by Linsanga
[2.0.11]

If a Cargo Landing Pad is constantly demanding a specific item, all drop pods sent down will be dedicated to that item, leading to starvation of other requests which are never sent down. This can even lead to starvation of manual drop slots, I've manually put an item into an orbital drop slot to have it delivered to the surface, only to find a few minutes later it hasn't been sent down due to a constant stream of drop pods all containing a small amount of iron plates.

Instead of sending down 20 iron plates every five seconds, I want it to send down 100 iron plates every thirty seconds, so it has time to send the other items I've requested.

There are two cases where I've seen this happen:
  • Constant use on planetside. The Landing Pad is requesting 800 iron plates and has almost 800, but there is an inserter constantly removing iron plates from the Landing Pad. Every time a drop pod is getting sent, it will see iron plates are at 780/800 requested and send an iron plate drop pod with 20 iron plates.
  • Constant production on platform. The Landing Pad has a large unmet request for iron plates, and the Platform is manufacturing a small trickle of them. Every time a drop pod is getting sent, 5 more iron plates have been inserted into the Space Platform Hub, so a drop pod gets sent with those 5 iron plates. Instead of first sending a drop pod for a different request, and then sending 10 iron plates in the following drop pod.
As far as I can tell, there is no reasonable way for me to avoid this issue. I've resorted to manually disabling inserters occasionally to allow other requests to catch up.

Several possible solutions (any one of these would fix my issue):
  • Cycle through all requests/items before re-sending an item. If iron plates were just delivered, give all other requests (and manual drop slots) a chance to send a drop pod before giving iron plates another drop pod.
  • Randomly select which request will be sent each time.
  • Allow a "custom minimum payload" selection, similar to the rocket requests going in the other direction. E.g. "I'm requesting 800 iron plates from orbit, but only send down a drop pod if you can send at least 200 plates. Don't send a drop pod if it will only contain 20 plates."
Save file is attached, the pioneer is just below a Cargo Landing Pad that should be getting steel and iron, but is only getting iron (a ton of wastefully small iron shipment).

Re: Orbital drop requests are starved by other requests

Posted: Sat Oct 26, 2024 9:25 pm
by Muche
How many Cargo bays do you have? I believe building more of them should help in this situation.

Re: Orbital drop requests are starved by other requests

Posted: Sat Oct 26, 2024 10:51 pm
by doktorstick
I have only two anecdotes, but it appears that the ordering of the logistic sections has priority from top to bottom. For instance, I often send excess iron ore to the planet, but it was starving other drops--as you noted--so on the landing platform I dragged the iron ore to the bottom.

Re: Orbital drop requests are starved by other requests

Posted: Sat Oct 26, 2024 11:04 pm
by Linsanga
I edited the original post to include a save file that demonstrates the problem. Only iron is being sent down when steel is also requested. The Platform has six cargo bays attached, and is certainly sending down enough drop pods to keep both iron and steel supplied.

Reordering so steel is prioritized would then just starve iron. If you have two resources being dropped, both of which are being inserted in/out at a constant rate, this will affect one of those resources.

Re: Orbital drop requests are starved by other requests

Posted: Sun Oct 27, 2024 6:07 am
by Linsanga
Oh, I just realized cargo bays can also be built planetside, which is maybe what you meant. My previous save file only had cargo bays on the platform, but here's a new save file with 6 cargo bays on each side, still starved of steel.

I do think this has increased the drop pod rate, which gives steel more chances to find a window of opportunity where no iron is being requested depending on the timing of the drops, but it's still pretty easy to end up in a situation where steel is locked out (e.g. attached save file).

Re: Orbital drop requests are starved by other requests

Posted: Mon Oct 28, 2024 9:02 pm
by martinvw
I've also noticed this problem. I think it would be useful if we could limit requests to only deliver full rockets.

Re: Orbital drop requests are starved by other requests

Posted: Mon Oct 28, 2024 11:25 pm
by DragoonGXG
Hello there,

your question has already been asked and answered.

You can find those link(s) here:
viewtopic.php?f=6&t=116921

If you are interested in more tips and tricks, try checking out viewtopic.php?f=18&t=117167.