proc_stats: moonraker process tracking

Track Moonraker CPU Usage, Rss Memory Usage, and Raspberry Pi Throttled State.

Signed-off-by:  Eric Callahan <arksine.code@gmail.com>

moonraker/moonraker.py

@@ -29,8 +29,8 @@ LOG_ATTEMPT_INTERVAL = int(2. / INIT_TIME + .5)
 MAX_LOG_ATTEMPTS = 10 * LOG_ATTEMPT_INTERVAL
 
 CORE_PLUGINS = [
-    'database', 'file_manager', 'klippy_apis',
-    'machine', 'data_store', 'shell_command']
+    'database', 'file_manager', 'klippy_apis', 'machine',
+    'data_store', 'shell_command', 'proc_stats']
 
 class Sentinel:
     pass

moonraker/plugins/proc_stats.py

@@ -0,0 +1,137 @@
+# Moonraker Process Stat Tracking
+#
+# Copyright (C) 2021 Eric Callahan <arksine.code@gmail.com>
+#
+# This file may be distributed under the terms of the GNU GPLv3 license.
+import time
+import re
+import os
+import pathlib
+import logging
+from collections import deque
+from tornado.ioloop import IOLoop, PeriodicCallback
+
+VC_GEN_CMD_FILE = "/usr/bin/vcgencmd"
+STATM_FILE_PATH = "/proc/self/smaps_rollup"
+STAT_UPDATE_TIME_MS = 1000
+REPORT_QUEUE_SIZE = 30
+THROTTLE_CHECK_INTERVAL = 10
+
+THROTTLED_FLAGS = {
+    1: "Under-Voltage Detected",
+    1 << 1: "Frequency Capped",
+    1 << 2: "Currently Throttled",
+    1 << 3: "Temperature Limit Active",
+    1 << 16: "Previously Under-Volted",
+    1 << 17: "Previously Frequency Capped",
+    1 << 18: "Previously Throttled",
+    1 << 19: "Previously Temperature Limited"
+}
+
+class ProcStats:
+    def __init__(self, config):
+        self.server = config.get_server()
+        self.ioloop = IOLoop.current()
+        self.stat_update_cb = PeriodicCallback(
+            self._handle_stat_update, STAT_UPDATE_TIME_MS)
+        self.vcgencmd = None
+        if os.path.exists(VC_GEN_CMD_FILE):
+            logging.info("Detected 'vcgencmd', throttle checking enabled")
+            shell_command = self.server.load_plugin(config, "shell_command")
+            self.vcgencmd = shell_command.build_shell_command(
+                "vcgencmd get_throttled")
+            self.server.register_notification("proc_stats:cpu_throttled")
+        else:
+            logging.info("Unable to find 'vcgencmd', throttle checking "
+                         "disabled")
+        self.smaps = pathlib.Path(STATM_FILE_PATH)
+        self.server.register_endpoint(
+            "/machine/proc_stats", ["GET"], self._handle_stat_request)
+        self.server.register_event_handler(
+            "server:klippy_shutdown", self._handle_shutdown)
+        self.proc_stat_queue = deque(maxlen=30)
+        self.last_update_time = time.time()
+        self.last_proc_time = time.process_time()
+        self.throttled = False
+        self.update_sequence = 0
+        self.stat_update_cb.start()
+
+    async def _handle_stat_request(self, web_request):
+        ts = None
+        if self.vcgencmd is not None:
+            ts = await self._check_throttled_state()
+        return {
+            'moonraker_stats': list(self.proc_stat_queue),
+            'throttled_state': ts
+        }
+
+    async def _handle_shutdown(self):
+        msg = "\nMoonraker System Usage Statistics:"
+        for stats in self.proc_stat_queue:
+            msg += f"\n{self._format_stats(stats)}"
+        logging.info(msg)
+        if self.vcgencmd is not None:
+            ts = await self._check_throttled_state()
+            logging.info(f"Throttled Flags: {' '.join(ts['flags'])}")
+
+    async def _handle_stat_update(self):
+        update_time = time.time()
+        proc_time = time.process_time()
+        time_diff = update_time - self.last_update_time
+        usage = round((proc_time - self.last_proc_time) / time_diff * 100, 2)
+        mem, mem_units = self._get_memory_usage()
+        self.proc_stat_queue.append({
+            "time": update_time,
+            "cpu_usage": usage,
+            "memory": mem,
+            "mem_units": mem_units
+        })
+        self.last_update_time = update_time
+        self.last_proc_time = proc_time
+        self.update_sequence += 1
+        if self.update_sequence == THROTTLE_CHECK_INTERVAL:
+            self.update_sequence = 0
+            if self.vcgencmd is not None:
+                ts = await self._check_throttled_state()
+                cur_throttled = ts['bits'] & 0xF
+                if cur_throttled and not self.throttled:
+                    logging.info(
+                        f"CPU Throttled State Detected: {ts['flags']}")
+                    self.server.send_event("proc_stats:cpu_throttled", ts)
+                self.throttled = cur_throttled
+
+    async def _check_throttled_state(self):
+        try:
+            resp = await self.vcgencmd.run_with_response(
+                timeout=.5, quiet=True)
+            ts = int(resp.strip().split("=")[-1], 16)
+        except Exception:
+            return {'bits': 0, 'flags': ["?"]}
+        flags = []
+        for flag, desc in THROTTLED_FLAGS.items():
+            if flag & ts:
+                flags.append(desc)
+        return {'bits': ts, 'flags': flags}
+
+    def _get_memory_usage(self):
+        try:
+            mem_data = self.smaps.read_text()
+            rss_match = re.search(r"Rss:\s+(\d+)\s+(\w+)", mem_data)
+            if rss_match is None:
+                return None, None
+            mem = int(rss_match.group(1))
+            units = rss_match.group(2)
+        except Exception:
+            return None, None
+        return mem, units
+
+    def _format_stats(self, stats):
+        return f"System Time: {stats['time']:2f}, " \
+               f"Usage: {stats['cpu_usage']}%, " \
+               f"Memory: {stats['memory']} {stats['mem_units']}"
+
+    def close(self):
+        self.stat_update_cb.stop()
+
+def load_plugin(config):
+    return ProcStats(config)