Revize 957aac06

re #9359 Implemented storing/retrieving payloads into/from a diskcache

client/api_client.py

@@ -5 +5 @@
 from diskcache import Deque
 from requests import HTTPError, ConnectionError
 
-from config_manager import server_url, server_port, server_endpoint, cache_dir, cache_retry_period_seconds, cache_max_retries, cache_max_entries
+from config_manager import server_url, server_port, server_endpoint, cache_dir, \
+    cache_retry_period_seconds, cache_max_retries, cache_max_entries
 
 
 _cache = Deque(directory=cache_dir)
@@ -19 +20 @@
         logging.info(f"response text: {response.text}")
     except ConnectionError:
         logging.warning(f"sending payload = {payload} to {_uri} failed")
+        _cache_failed_payload(payload)
     except HTTPError as error:
         logging.error(f"HTTP Error ({_uri}) payload = {payload}, {error}")
+        _cache_failed_payload(payload)
+
+
+def _cache_failed_payload(payload: dict):
+    if len(_cache) >= cache_max_entries:
+        oldest_payload = _cache.pop()
+        logging.warning(f"cache is full - discarding payload = {oldest_payload}")
+
+    logging.info(f"adding payload = {payload} into cache")
+    _cache.append(payload)
 
 
 def api_client_run():
     while True:
+        retries = min(cache_max_retries, len(_cache))
+        logging.info(f"emptying the cache ({retries} records)")
+        for _ in range(0, retries):
+            payload = _cache.pop()
+            send_data(payload)
         sleep(cache_retry_period_seconds)