perf: use two-second minimum Raspberry Pi collection cadence

plugin/manifest.json

@@ -1,7 +1,7 @@
 {
   "id": "pigway-agent",
   "name": "PIGWay Raspberry Pi Agent",
-  "version": "1.3.0",
+  "version": "1.3.1",
   "protocol_version": 1,
   "entrypoint": "worker.py",
   "runtime": "python3",
@@ -40,6 +40,6 @@
   },
   "legacy_connection_fields": true,
   "collection": {
-    "interval_seconds": 1
+    "interval_seconds": 2
   }
 }

plugin/worker.py

@@ -56,6 +56,14 @@ def request(device, endpoint, method='GET', payload=None, query=None):
         raise AdapterError('RESULT_UNKNOWN' if method == 'PUT' else 'DEVICE_UNAVAILABLE') from None
 
 
+def collection_interval(value):
+    declaration = value.get('collection', {})
+    interval = declaration.get('interval_seconds') if isinstance(declaration, dict) else None
+    if not isinstance(interval, (int, float)) or isinstance(interval, bool) or not math.isfinite(interval) or not 1 <= interval <= 3600:
+        interval = MANIFEST['collection']['interval_seconds']
+    return max(MANIFEST['collection']['interval_seconds'], interval)
+
+
 def collect(device):
     value = request(device, '/status')
     if not isinstance(value.get('system'), dict) or not isinstance(value.get('machine'), dict):
@@ -88,7 +96,7 @@ def collect(device):
     return {'schema_version': 1, 'observed_at': value.get('timestamp'),
             'identity': {'reported_name': value['machine'].get('name'), 'category': 'host',
                          'details': value.get('device', {})},
-            'collection': value.get('collection', MANIFEST['collection']),
+            'collection': {'interval_seconds': collection_interval(value)},
             'capabilities': MANIFEST['capabilities'], 'metrics': metrics,
             'resources': [{'id': 'host', 'type': 'host'}],
             'alerts': value.get('display', {}).get('alerts', []),

tests/test_metrics.py

@@ -21,9 +21,14 @@ class MetricsTests(unittest.TestCase):
         self.assertEqual(values['network_rx_bytes_per_second'],0)
         self.assertEqual(values['network_tx_bytes_per_second'],1234)
         self.assertEqual(next(m['observed_at'] for m in result['metrics'] if m['key']=='network_tx_bytes_per_second'),120)
-        self.assertEqual(result['collection']['interval_seconds'],1)
+        self.assertEqual(result['collection']['interval_seconds'],2)
         self.assertTrue(result['alerts_complete'])
 
+    def test_collection_minimum_and_slower_device(self):
+        self.assertEqual(worker.collection_interval({'collection':{'interval_seconds':1}}),2)
+        self.assertEqual(worker.collection_interval({'collection':{'interval_seconds':5}}),5)
+        self.assertEqual(worker.collection_interval({'collection':{'interval_seconds':True}}),2)
+
     def test_absent_or_boolean_fields_not_invented(self):
         value={'system': {'cpu_percent': True}, 'machine':{}, 'network': {'link_speed_mbps': None, 'rx_bytes_per_second':float('nan'), 'tx_bytes_per_second':True}}
         with patch.object(worker,'request',return_value=value): result=worker.collect({})