Fix: use GiB for balance computations (#485)

Problem: we now which to use powers of two for memory resources.

Author: odesenfans

deployment/migrations/versions/0018_7bcb8e5fe186_fix_vm_cost_view.py

@@ -135,7 +135,7 @@ def upgrade() -> None:
              LATERAL ( SELECT file_volumes_size.file_volumes_size +
                               other_volumes_size.other_volumes_size::numeric AS required_disk_space) used_disk,
              LATERAL ( SELECT ceil(GREATEST(ceil((vms.resources_vcpus / 1)::double precision),
-                                            (vms.resources_memory / 2000)::double precision)) AS compute_units_required) cu,
+                                            (vms.resources_memory / 2048)::double precision)) AS compute_units_required) cu,
              LATERAL ( SELECT CASE
                                   WHEN COALESCE(vms.persistent, true)
                                       THEN '21474836480'::bigint::double precision * cu.compute_units_required

src/aleph/services/cost.py

@@ -78,7 +78,7 @@ def get_additional_storage_price(
 
 def _get_nb_compute_units(content: ExecutableContent) -> int:
     cpu = content.resources.vcpus
-    memory = math.ceil(content.resources.memory / 2000)
+    memory = math.ceil(content.resources.memory / 2048)
     nb_compute_units = cpu if cpu >= memory else memory
     return nb_compute_units