Refactored healthcheck and failure detector to extend default one (#3747)

Author: vladvildanov

redis/multidb/client.py

@@ -22,10 +22,17 @@ class MultiDBClient(RedisModuleCommands, CoreCommands):
     """
     def __init__(self, config: MultiDbConfig):
         self._databases = config.databases()
-        self._health_checks = config.default_health_checks() if config.health_checks is None else config.health_checks
+        self._health_checks = config.default_health_checks()
+
+        if config.health_checks is not None:
+            self._health_checks.extend(config.health_checks)
+
         self._health_check_interval = config.health_check_interval
-        self._failure_detectors = config.default_failure_detectors() \
-            if config.failure_detectors is None else config.failure_detectors
+        self._failure_detectors = config.default_failure_detectors()
+
+        if config.failure_detectors is not None:
+            self._failure_detectors.extend(config.failure_detectors)
+
         self._failover_strategy = config.default_failover_strategy() \
             if config.failover_strategy is None else config.failover_strategy
         self._failover_strategy.set_databases(self._databases)

redis/multidb/config.py

@@ -51,10 +51,10 @@ class MultiDbConfig:
         databases_config: A list of database configurations.
         client_class: The client class used to manage database connections.
         command_retry: Retry strategy for executing database commands.
-        failure_detectors: Optional list of failure detectors for monitoring database failures.
+        failure_detectors: Optional list of additional failure detectors for monitoring database failures.
         failure_threshold: Threshold for determining database failure.
         failures_interval: Time interval for tracking database failures.
-        health_checks: Optional list of health checks performed on databases.
+        health_checks: Optional list of additional health checks performed on databases.
         health_check_interval: Time interval for executing health checks.
         health_check_retries: Number of retry attempts for performing health checks.
         health_check_backoff: Backoff strategy for health check retries.

tests/test_multidb/conftest.py

@@ -94,7 +94,6 @@ def mock_multi_db_config(
      config = MultiDbConfig(
           databases_config=[Mock(spec=DatabaseConfig)],
           failure_detectors=[mock_fd],
-          health_checks=[mock_hc],
           health_check_interval=hc_interval,
           failover_strategy=mock_fs,
           auto_fallback_interval=auto_fallback_interval,