Lumbridge Compute: telemetry and four-lane operations

tools/scrape_vllm_metrics.py

@@ -0,0 +1,94 @@
+#!/usr/bin/env python3
+"""Scrape vLLM's own Prometheus /metrics on each locally-served model and append
+one JSON snapshot line per reachable model to vllm_snapshots.jsonl.
+
+vLLM counters (prompt_tokens_total, generation_tokens_total, request_success_total)
+reset to zero on every process restart -- this is what turns them into a durable
+history. A model that's down is skipped for this tick, not an error: run this
+every few minutes from cron and it just accumulates whatever was actually up.
+"""
+import json
+import os
+import re
+import time
+import urllib.request
+
+USAGE_DIR = os.path.expanduser("~/lumbridge/compute/.compute/usage")
+SNAPSHOT_FILE = os.path.join(USAGE_DIR, "vllm_snapshots.jsonl")
+
+# model_name -> port, per registry/models.yaml
+MODELS = {
+    "brain": 8001,
+    "embed": 8012,
+    "ocr": 8013,
+}
+
+# Prometheus exposition line: metric{labels} value
+# vLLM metric names contain a colon (vllm:prompt_tokens_total), which \w does not match.
+LINE_RE = re.compile(r'^([\w:]+)(\{[^}]*\})?\s+([0-9eE+\-.]+)\s*$')
+
+COUNTERS = (
+    "vllm:prompt_tokens_total",
+    "vllm:generation_tokens_total",
+    "vllm:num_requests_running",
+)
+# request_success_total is split by finished_reason -- sum all reasons.
+SUCCESS_METRIC = "vllm:request_success_total"
+
+
+def _fetch(port):
+    url = f"http://127.0.0.1:{port}/metrics"
+    with urllib.request.urlopen(url, timeout=3) as resp:
+        return resp.read().decode()
+
+
+def _parse(text):
+    values = {name: 0.0 for name in COUNTERS}
+    success_total = 0.0
+    for line in text.splitlines():
+        if not line or line.startswith("#"):
+            continue
+        m = LINE_RE.match(line)
+        if not m:
+            continue
+        name, value = m.group(1), m.group(3)
+        try:
+            value = float(value)
+        except ValueError:
+            continue
+        if name in values:
+            values[name] = value
+        elif name == SUCCESS_METRIC:
+            success_total += value
+    values[SUCCESS_METRIC] = success_total
+    return values
+
+
+def main():
+    os.makedirs(USAGE_DIR, exist_ok=True)
+    ts = time.time()
+    lines = []
+    for model, port in MODELS.items():
+        try:
+            text = _fetch(port)
+        except Exception:
+            continue  # model is down -- skip silently, not an error
+        parsed = _parse(text)
+        record = {
+            "ts": ts,
+            "model": model,
+            "prompt_tokens_total": parsed["vllm:prompt_tokens_total"],
+            "generation_tokens_total": parsed["vllm:generation_tokens_total"],
+            "request_success_total": parsed[SUCCESS_METRIC],
+            "num_requests_running": parsed["vllm:num_requests_running"],
+        }
+        lines.append(json.dumps(record))
+    if lines:
+        with open(SNAPSHOT_FILE, "a") as f:
+            for line in lines:
+                f.write(line + "\n")
+    print(f"scraped {len(lines)}/{len(MODELS)} models reachable")
+
+
+if __name__ == "__main__":
+    main()