[2.1.12] Saturated Cargo Landing Pad on Fulgora + infinite space-platform output spawns unbounded deconstruction-marked

[fishblade2592]

Version: 2.1.12 (win64, steam, Space Age, no mods) — verify against factorio-current.log first line

Save file: SorryfortooLATE
not attached. Issue was resolved in-place by console-clearing ground items, so I am not uploading the save. Repro path below is enough to trigger from a clean save.

What I expected:

When a Cargo Landing Pad is saturated and a space platform keeps dispatching cargo pods, overflow should be rejected at orbital logistics or bounded. It should not silently create an ever-growing set of ground items auto-marked for deconstruction. UPS should stay 60.

What happened (on Fulgora):

Cargo Landing Pad had downstream consumption stopped (production line halted).
- A space platform was set to continuously send one item type to that pad.

Pad inventory saturated, pods kept arriving → pad ejected items onto ground next to it → those ground items were automatically marked for robot pickup / deconstruction (red markers).
- Because platform output is effectively infinite, ground items accumulated without bound (thousands of decon-marked  item-on-ground  entities).
- F4 → show-time-usage: Construction manager low average, but max ~100 ms/tick periodically. UPS and FPS dropped together at those moments (not GPU/render).
- I first suspected an oversized deconstruction blueprint, removed it → spikes persisted.

Inspecting the pad I found the ground around it covered in decon-marked overflow items from the landing pad.
- I then ran the standard console clear:
 /c for _, i in pairs(game.player.surface.find_entities_filtered{name="item-on-ground"}) do i.destroy() end 
Immediately after the clear, Construction manager max-time dropped to normal (<1 ms), UPS and FPS returned to 60/60, and the periodic spikes never came back while the platform was still stopped.
- Later re-enabling platform dispatch made the pile grow again and spikes returned, confirming direction.

Root cause (analysis):

Performance leak via feedback loop with no back-pressure:

saturated Cargo Landing Pad + still-producing orbital source → items ejected to ground → auto-marked for deconstruction → Construction manager must scan/re-evaluate a monotonically growing ground-item ghost set every tick. The set only grows while the platform sends cargo; it is not bounded by pad inventory, robot count, or logistic network state. Scales with runtime, not factory size. Clearing ground items removes the symptom; the leak is in the overflow→decon-mark path.

Steps to reproduce (clean save):

2.1.12 experimental, Space Age, no mods.

On Fulgora build a Cargo Landing Pad; do NOT consume its output.
3. Space platform loops sending that item to the pad.

Wait until pad saturates and ground items appear + get red decon markers.
5. F4 → show-time-usage: Construction manager max climbs to ~100ms periodically; UPS/FPS dip together.
6. Run the console clear above → UPS/FPS recover instantly.

Resume platform dispatch → pile regrows → spikes return.

Debug data I can provide if asked:

factorio-current.log (version line)

F4 show-time-usage screenshot during spike (Construction manager max ~100ms, only the 5 required toggles on)
- F4 screenshot at 60/60 after console clear

(no save attached, see note above)

Notes:

Not the 2.0.8 ground-item-on-platform crash, not the 2.0.14 cargo-bay GUI UPS issue — both fixed. This is specifically unbounded deconstruction-marked ground-item creation from a saturated landing pad with infinite orbital input, on 2.1.x experimental. Suggested direction: cap/reject pad overflow when downstream saturated, or do not auto-mark ejected overflow items for deconstruction.

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[Rseding91]

Thanks for the report. Could you provide a save file where this is happening?

[fishblade2592]

Thanks for the report. Could you provide a save file where this is happening?

Thanks for the follow-up. Unfortunately, I have already deleted the platform and overwritten the save file while fixing it manually.

However, you can easily reproduce this by building a dedicated test setup. Here is the recipe:

1.On Fulgora:​ Place a Cargo Landing Pad.

2.Orbit:​ Build a Space Platform Hub and set up a loop sending a large amount of item to that pad constantly.

I use request like this,cause lot of item dorp to planet

07-29-2026, 23-26-05.png (28.19 KiB) Viewed 430 times

3.Ground Setup:​ Surround the pad with a few Cargo Bays set to "Remove unrequested items." This ensures the pad continuously receives and clears items.

set like this

07-29-2026, 23-25-07.png (149.43 KiB) Viewed 430 times

4.Observe:​ Once the pad inventory is full and construction robots stall, it will start spilling items onto the ground. These items will immediately get marked for deconstruction (red markers).

In my save, the planet blacked out, which stopped the items from being consumed.

07-29-2026, 23-27-21.png (3.04 MiB) Viewed 430 times

Result:​ With the infinite input, the number of these marked ground entities will grow indefinitely, causing the Construction manager to spike in performance usage (as seen in the F4 debug menu).

This setup should reliably trigger the feedback loop bug.

[fishblade2592]

Thanks for the report. Could you provide a save file where this is happening?

07-30-2026, 18-16-28.png (1.32 MiB) Viewed 358 times

I found a screenshot after canceling the item redmap.

[boskid]

Ref 134798 (i will not call it duplicate because i do not know if its the same and since it appeared again it may be worth investigating).

[Rseding91]

It looks like the platform auto trash logic does not account for the available space in the landing pad when sending trash down. It likely should to avoid this situation. The spill onto ground logic is mostly meant as a backup to avoid deleting items and not a scenario that’s supposed to just happen when the inventory is regularly full.