Idempotency: Use special cache, keep for 6 hours.

lib/pleroma/application.ex

@@ -23,6 +23,18 @@ defmodule Pleroma.Application do
             limit: 2500
           ]
         ]),
+        worker(
+          Cachex,
+          [
+            :idempotency_cache,
+            [
+              default_ttl: :timer.seconds(6 * 60 * 60),
+              ttl_interval: :timer.seconds(60),
+              limit: 2500
+            ]
+          ],
+          id: :cachex_idem
+        ),
         worker(Pleroma.Web.Federator, []),
         worker(Pleroma.Gopher.Server, []),
         worker(Pleroma.Stats, [])

lib/pleroma/web/mastodon_api/mastodon_api_controller.ex

@@ -283,13 +283,11 @@ defmodule Pleroma.Web.MastodonAPI.MastodonAPIController do
 
     {:ok, activity} =
       Cachex.get!(
-        :user_cache,
-        "idem:#{idempotency_key}",
+        :idempotency_cache,
+        idempotency_key,
         fallback: fn _ -> CommonAPI.post(user, params) end
       )
 
-    Cachex.expire(:user_cache, "idem:#{idempotency_key}", :timer.seconds(5 * 60))
-
     render(conn, StatusView, "status.json", %{activity: activity, for: user, as: :activity})
   end