Add test cases for health monitor

Author: bomanaps

libp2p/__init__.py

@@ -365,28 +365,36 @@ def new_host(
         effective_connection_config = quic_transport_opt
 
         # If both connection_config and quic_transport_opt are provided,
-        # merge health monitoring settings
+        # merge ALL connection and health monitoring settings
         if connection_config is not None:
-            # Merge health monitoring settings from connection_config
-            # into quic_transport_opt
-            if hasattr(connection_config, "enable_health_monitoring"):
-                quic_transport_opt.enable_health_monitoring = (
-                    connection_config.enable_health_monitoring
-                )
-            if hasattr(connection_config, "health_check_interval"):
-                quic_transport_opt.health_check_interval = (
-                    connection_config.health_check_interval
-                )
-            if hasattr(connection_config, "load_balancing_strategy"):
-                quic_transport_opt.load_balancing_strategy = (
-                    connection_config.load_balancing_strategy
-                )
-            if hasattr(connection_config, "max_connections_per_peer"):
-                quic_transport_opt.max_connections_per_peer = (
-                    connection_config.max_connections_per_peer
-                )
+            # Merge all ConnectionConfig attributes from connection_config
+            # into quic_transport_opt (which inherits from ConnectionConfig)
+            connection_config_attrs = [
+                "max_connections_per_peer",
+                "connection_timeout",
+                "load_balancing_strategy",
+                "enable_health_monitoring",
+                "health_initial_delay",
+                "health_warmup_window",
+                "health_check_interval",
+                "ping_timeout",
+                "min_health_threshold",
+                "min_connections_per_peer",
+                "latency_weight",
+                "success_rate_weight",
+                "stability_weight",
+                "max_ping_latency",
+                "min_ping_success_rate",
+                "max_failed_streams",
+                "unhealthy_grace_period",
+            ]
+
+            for attr in connection_config_attrs:
+                if hasattr(connection_config, attr):
+                    setattr(quic_transport_opt, attr, getattr(connection_config, attr))
+
             logger.info(
-                "Merged health monitoring settings from "
+                "Merged all connection and health monitoring settings from "
                 "connection_config into QUIC config"
             )
     elif connection_config is not None:

newsfragments/915.feature.rst

@@ -0,0 +1,30 @@
+Add comprehensive connection health monitoring and intelligent load balancing to libp2p.
+
+**Connection Health Metrics:**
+- Implements ConnectionHealth dataclass with latency tracking, success rates, bandwidth monitoring, and error history
+- Provides weighted health scoring algorithm with configurable weights (latency, success rate, stability)
+- Tracks connection age, idle time, stream lifecycle, and performance trends
+- Monitors bandwidth usage with time-windowed tracking and peak/average calculations
+
+**Proactive Monitoring Service:**
+- Implements ConnectionHealthMonitor service with periodic health checks and automatic connection replacement
+- Performs non-intrusive ping-based health verification with configurable intervals
+- Supports warmup windows and grace periods to prevent premature connection replacement
+- Automatically maintains minimum connection count per peer while replacing unhealthy connections
+
+**Health-Aware Load Balancing:**
+- Adds four connection selection strategies: round_robin, least_loaded, health_based, and latency_based
+- Routes traffic to healthiest/lowest-latency connections for optimal performance
+- Provides fallback behavior when health data unavailable
+
+**API Consistency Fix:**
+- Extends new_host() to accept connection_config parameter, resolving previous API inconsistency
+- Maintains full backward compatibility with existing code
+- Supports health monitoring configuration through high-level host API
+- Properly merges health settings with QUIC transport configuration when both are provided
+
+**Configuration and Integration:**
+- Adds comprehensive ConnectionConfig options for health monitoring customization
+- Integrates health tracking throughout connection lifecycle (establishment, usage, closure)
+- Provides health summary and metrics export through host interface
+- Includes extensive test coverage with 80+ new tests covering all components