[model-gateway] Add Redis support as a history backend (#16300)

sgl-model-gateway/bindings/python/src/sglang_router/router.py

@@ -10,6 +10,7 @@ from sglang_router.sglang_router_rs import (
     PyJwtConfig,
     PyOracleConfig,
     PyPostgresConfig,
+    PyRedisConfig,
     PyRole,
 )
 from sglang_router.sglang_router_rs import Router as _Router
@@ -63,6 +64,8 @@ def history_backend_from_str(backend_str: Optional[str]) -> HistoryBackendType:
         return HistoryBackendType.Oracle
     elif backend_lower == "postgres":
         return HistoryBackendType.Postgres
+    elif backend_lower == "redis":
+        return HistoryBackendType.Redis
     else:
         raise ValueError(f"Unknown history backend: {backend_str}")
 
@@ -262,6 +265,20 @@ class Router:
             )
         args_dict["postgres_config"] = postgres_config
 
+        # Convert Redis config if needed
+        redis_config = None
+        if history_backend == HistoryBackendType.Redis:
+            retention_days = args_dict.get("redis_retention_days", 30)
+            # If retention_days is negative, it means persistent storage (None in Rust)
+            retention_arg = None if retention_days < 0 else retention_days
+
+            redis_config = PyRedisConfig(
+                url=args_dict.get("redis_url"),
+                pool_max=args_dict.get("redis_pool_max", 16),
+                retention_days=retention_arg,
+            )
+        args_dict["redis_config"] = redis_config
+
         # Build control plane auth config
         args_dict["control_plane_auth"] = build_control_plane_auth_config(args_dict)
 
@@ -278,6 +295,9 @@ class Router:
             "oracle_pool_timeout_secs",
             "postgres_db_url",
             "postgres_pool_max",
+            "redis_url",
+            "redis_pool_max",
+            "redis_retention_days",
             # Control plane auth fields (converted to control_plane_auth)
             "control_plane_api_keys",
             "control_plane_audit_enabled",

sgl-model-gateway/bindings/python/src/sglang_router/router_args.py

@@ -117,6 +117,9 @@ class RouterArgs:
     oracle_pool_timeout_secs: int = 30
     postgres_db_url: Optional[str] = None
     postgres_pool_max: int = 16
+    redis_url: Optional[str] = None
+    redis_pool_max: int = 16
+    redis_retention_days: int = 30
     # mTLS configuration for worker communication
     client_cert_path: Optional[str] = None
     client_key_path: Optional[str] = None
@@ -200,6 +203,9 @@ class RouterArgs:
         postgres_group = parser.add_argument_group(
             "PostgreSQL Database", "PostgreSQL database backend configuration"
         )
+        redis_group = parser.add_argument_group(
+            "Redis Database", "Redis database backend configuration"
+        )
         tls_group = parser.add_argument_group(
             "TLS/mTLS Security", "TLS certificates for server and worker communication"
         )
@@ -663,7 +669,7 @@ class RouterArgs:
             f"--{prefix}history-backend",
             type=str,
             default=RouterArgs.history_backend,
-            choices=["memory", "none", "oracle", "postgres"],
+            choices=["memory", "none", "oracle", "postgres", "redis"],
             help="History storage backend for conversations and responses (default: memory)",
         )
 
@@ -733,6 +739,28 @@ class RouterArgs:
             help="Maximum PostgreSQL connection pool size (default: 16, env: POSTGRES_POOL_MAX)",
         )
 
+        # Redis configuration
+        redis_group.add_argument(
+            f"--{prefix}redis-url",
+            type=str,
+            default=os.getenv("REDIS_URL"),
+            help="Redis connection URL (env: REDIS_URL)",
+        )
+        redis_group.add_argument(
+            f"--{prefix}redis-pool-max",
+            type=int,
+            default=int(os.getenv("REDIS_POOL_MAX", RouterArgs.redis_pool_max)),
+            help="Maximum Redis connection pool size (default: 16, env: REDIS_POOL_MAX)",
+        )
+        redis_group.add_argument(
+            f"--{prefix}redis-retention-days",
+            type=int,
+            default=int(
+                os.getenv("REDIS_RETENTION_DAYS", RouterArgs.redis_retention_days)
+            ),
+            help="Redis data retention in days (-1 for persistent, default: 30, env: REDIS_RETENTION_DAYS)",
+        )
+
         # TLS/mTLS configuration
         tls_group.add_argument(
             f"--{prefix}client-cert-path",