Design 47: the bus module is wanted like any module, and only a put replaces its server (issue 774, the operator 2026-11-03)

Claude-Session: https://claude.ai/code/session_01NcbgfJ9Gum47zkFKWRaovL
2026-11-03 01:37:31 +01:00
parent 4d4524cda3
commit ae4c90f990
1 changed files with 11 additions and 0 deletions
@@ -845,6 +845,17 @@ backup holder backs up nothing, and the have says so.
  fingerprint, the digest, the phase and the health after the module's start window. A failed apply is loud,
  retried by the next change of the want or the composition, never by a clock, and fixed forward (ADR 0360 §8,
  ADR 0539 §9).
+- **The bus module is wanted like any module; its server moves only by a put.** "The bus moves" (ADR 0539 §15,
+  ADR 0546 §8) means its server is replaced. So the assigner writes the bus module's want by the same rules as
+  every module's, and the node agent applies what that want brings (its files, its processes' bus accounts and
+  secrets, its tools) while it keeps the server's container as it runs. Only a want written by a put, on the
+  operator's warrant after the streams' snapshot, replaces the server. mesh-sdk names the resources the bus's
+  server holds, so the assigner and the node agent read one list; a node agent that does not know the list yet is
+  never sent a want for the bus module, so the node agent's hold is delivered before the assigner's change. Until
+  then nothing writes the bus module's process accounts, and its tools that write to the bus fail (issue 774, the
+  operator, 2026-11-03). How it is checked: a node agent unit test applies a bus module's new want and shows the
+  server's container untouched and the tools' account written; an assigner unit test writes the bus module's want
+  by the rules and holds the server's replacement for a put.
 - **Every want is owed.** The watchman mirrors every want as a pulse owed by that node's agent until its have
  names the want's fingerprint, so a node that does not move is a stall (ADR 0539 §19).
 - **A move a person must allow is judged by the node and asked by the assigner.** The node agent applies ADR 0377