more exception safe

miscellaneous/monitor-client.service

@@ -5,6 +5,7 @@ After=network.target
 [Service]
 User=cloud
 Group=cloud
+SyslogIdentifier=monitor-client
 WorkingDirectory=/home/cloud/monitor-client
 ExecStart=/bin/bash -c "source /etc/profile; workon monitor-client; exec python manage.py run"
 Restart=always

src/client.py

@@ -156,53 +156,69 @@ class Client:
         now = time.time()
         running_vms = []
 
-        try:
-            for entry in psutil.process_iter():
-                if entry.name() in ('kvm', 'qemu-system-x86_64'):
         parser = argparse.ArgumentParser(add_help=False)
         parser.add_argument('-name')
-                    # FONTOS: nincs szóköz a '-m' végén, és saját parse függvényt használunk
+        # '-m ' (with trailing space) is intentional to avoid collision with '-machine'
         parser.add_argument('--memory-size', '-m ', dest='memory_size',
                         type=parse_memory_size)
-                    args, unknown = parser.parse_known_args(entry.cmdline()[1:])
+        try:
+            for entry in psutil.process_iter(attrs=['pid', 'name', 'cmdline']):
+                info = entry.info
+                pid = info.get('pid')
+                name = info.get('name')
+                cmdline = info.get('cmdline')
+                if not name or name not in ('kvm', 'qemu-system-x86_64'):
+                   continue
+                if not cmdline or len(cmdline) < 2:
+                    logger.debug('Pid %s: empty or too short cmdline: %r', pid, cmdline)
+                    continue
 
-                    # for Red Hat style parametering of kvm
+                try:
+                    args, unknown = parser.parse_known_args(cmdline[1:])
+                except SystemExit:
+                    logger.warning("Argparse failed pid=%s cmdline=%r", pid, cmdline)
+                    continue
                 if isinstance(args.name, str):
                     args.name = re.sub(r"^guest=", "", args.name)
                     args.name = re.sub(r",debug-threads=.*$", "", args.name)
 
-                        process = self.processes.get(entry.pid, None)
-                        if not process or process.cmdline() != entry.cmdline():
-                            process = psutil.Process(entry.pid)
+                    process = self.processes.get(pid, None)
+                    if not process:
+                        process = psutil.Process(pid)
                         logger.info('New process: %s', process)
-                            self.processes[entry.pid] = process
+                        self.processes[pid] = process
+                        # no cpu_perc info when process appears first
+                    else: 
+                        cpu_perc = process.cpu_percent()
+                        metrics.append('vm.%(name)s.cpu.percent %(value)f %(time)d' % {
+                            'name': args.name,
+                            'value': cpu_perc,
+                            'time': now,
+                        })
 
                     if args.memory_size:
                         # args.memory_size MiB-ben van
                         rss_bytes = float(process.memory_info().rss)
                         mem_bytes_total = args.memory_size * 1024 ** 2
                         mem_perc = (rss_bytes / mem_bytes_total) * 90.0
-                
                         metrics.append('vm.%(name)s.memory.usage %(value)f %(time)d' % {
                             'name': args.name,
                             'value': mem_perc,
                             'time': now,
                         })
                     else:
-                            logger.warning('Pid %d: no memory size found for VM %s', entry.pid, args.name)
+                        logger.warning('Pid %d: no memory size found for VM %s', pid, args.name)
 
-                        cpu_perc = process.cpu_percent()
-                        metrics.append('vm.%(name)s.cpu.percent %(value)f %(time)d' % {
-                            'name': args.name,
-                            'value': cpu_perc,
-                            'time': now,
-                        })
                     running_vms.append(args.name)
                 else:
-                        logger.warning('Pid: %d args.name is empty?: %s %s',
-                                       entry.pid, entry.name(), entry.cmdline())
-        except (psutil.NoSuchProcess, TypeError):
-            logger.warning('Process %d lost. Entry: %s', entry.pid, entry.cmdline()[0:])
+                    logger.warning('Pid: %d args.name is empty?: %s %s', pid, name, cmdline)
+        except Exception:
+            logger.exception(
+                "collect_vms failed: pid=%s name=%r cmdline=%r",
+                locals().get("pid", "?"),
+                locals().get("name", None),
+                locals().get("cmdline", None),
+            )
 
         interfaces = psutil.net_io_counters(pernic=True)
         for interface, data in interfaces.items():
@@ -243,8 +259,10 @@ class Client:
         metricCollectors parameter that should be provided by the collectables
         modul to work properly.
         """
+        CACHE_TTL = 1 * 24 * 3600  # One day
         self.connect()
         self.processes = {}
+        self.last_cache_cleaup = time.time()
         try:
             while True:
                 metrics = self.collect_node() + self.collect_vms()
@@ -253,7 +271,11 @@ class Client:
                         self.send(chunk)
                     logger.debug("metrics: %r", metrics)
                     logger.info("%d metrics sent", len(metrics))
+                if time.time() - self.last_cache_cleaup > CACHE_TTL:
+                    self.processes.clear()
+                    self.last_cache_cleaup = time.time()
                 time.sleep(10)
+
         except KeyboardInterrupt:
             logger.info("Reporting has stopped by the user. Exiting...")
         finally: