balancing improvements

packages/node/meshnet_node/startup.py

@@ -482,7 +482,7 @@ def _warn_virtual_network_ip(ip: str | None) -> None:
 def run_startup(
     tracker_url: str,
     port: int = 0,
-    model: str = "stub-model",
+    model: str | None = None,
     model_id: str | None = None,
     shard_start: int | None = None,
     shard_end: int | None = None,
@@ -755,8 +755,9 @@ def run_startup(
     # query below (/v1/nodes/assign?model=…) is authoritative there, and a fresh
     # tracker would otherwise print a scary 503 for the model-less auto-join.
     net_assignment: dict = {}
-    if model and model != "stub-model":
-        print(f"Model {model!r} requested explicitly — skipping network auto-join.", flush=True)
+    if model_id or (model and model != "stub-model"):
+        if model:
+            print(f"Model {model!r} requested explicitly — skipping network auto-join.", flush=True)
     else:
         print("Querying tracker for network assignment...", flush=True)
         assign_qs = urllib.parse.urlencode({"device": device, "vram_mb": assignment_vram_mb, "ram_mb": ram_mb})
@@ -767,17 +768,25 @@ def run_startup(
     assigned_hf_repo: str | None = net_assignment.get("hf_repo")
     _gap_found: bool = bool(net_assignment.get("gap_found", False))
 
-    if assigned_hf_repo and _gap_found:
+    if assigned_hf_repo:
         assigned_shard_start: int = net_assignment["shard_start"]
         assigned_shard_end: int = net_assignment["shard_end"]
         assigned_num_layers: int = net_assignment["num_layers"]
         assigned_model_sources: list[dict] = net_assignment.get("model_sources", [])
-        print(
-            f"  Assigned: {assigned_hf_repo} "
-            f"layers {assigned_shard_start}–{assigned_shard_end} "
-            f"(of {assigned_num_layers})",
-            flush=True,
-        )
+        if _gap_found:
+            print(
+                f"  Assigned gap: {assigned_hf_repo} "
+                f"layers {assigned_shard_start}–{assigned_shard_end} "
+                f"(of {assigned_num_layers})",
+                flush=True,
+            )
+        else:
+            print(
+                f"  Assigned redundant copy: {assigned_hf_repo} "
+                f"layers {assigned_shard_start}–{assigned_shard_end} "
+                f"(of {assigned_num_layers})",
+                flush=True,
+            )
         full_sources = [] if tracker_source_disabled else _full_model_sources(assigned_model_sources)
         if full_sources:
             print("Downloading assigned model snapshot...", flush=True)
@@ -874,10 +883,16 @@ def run_startup(
         )
         return node
 
-    # 3b. Shard assignment from tracker (stub-model / preset-based path)
+    if model != "stub-model":
+        raise RuntimeError(
+            "Tracker did not assign a model. Join a network that already serves one, "
+            "or start with --model <HF_REPO>."
+        )
+
+    # 3b. Stub preset path (tests / explicit stub-model only)
     print("Querying tracker for shard assignment...", flush=True)
     assign_qs = urllib.parse.urlencode({
-        "model": model,
+        "model": model or "stub-model",
         "device": device,
         # CPU-mode nodes must be sized by RAM: a detected-but-unusable GPU's
         # VRAM would otherwise cap the shard (e.g. 8 GB VRAM → 3 layers on a