feat(routing): consistent_hash strategy + priority tiers; fold weighted into round_robin

README.md

@@ -154,10 +154,11 @@ Covered by 183 end-to-end scenario files (496 cases) that run against real gatew
 - **Anthropic Messages API** — `POST /v1/messages` as a first-class route, working against
   **any** configured upstream: requests and responses (including streaming) are translated
   both ways when a model points at a non-Anthropic provider.
-- **Routing & failover** — virtual/routing models with six strategies: `round_robin`,
-  `weighted` (with sticky/canary hashing), `failover`, plus metric-based `least_cost`,
-  `least_latency`, and `least_busy`. Retry budgets, cooldowns, tag-conditional targets,
-  and per-attempt timeouts.
+- **Routing & failover** — virtual/routing models with six strategies: `round_robin`
+  (smooth weighted round-robin), `consistent_hash` (session affinity keyed by header /
+  cookie / API key / client IP), `failover`, plus metric-based `least_cost`,
+  `least_latency`, and `least_busy`. Per-target `priority` tiers (active/backup pools),
+  retry budgets, cooldowns, tag-conditional targets, and per-attempt timeouts.
 - **Ensemble models** — fan one request out to a panel of models concurrently, then have a
   judge model synthesize a single answer, with a minimum-successful-responses threshold.
 - **Semantic routing** — one virtual model that dispatches by the *meaning* of each

crates/aisix-admin/src/openapi.rs

@@ -2234,13 +2234,17 @@ fn add_variant_titles(doc: &mut Value) {
             "/components/schemas/RoutingStrategy/oneOf",
             &[
                 "Round robin",
-                "Weighted",
+                "Consistent hash",
                 "Failover",
                 "Least cost",
                 "Least latency",
                 "Least busy",
             ],
         ),
+        (
+            "/components/schemas/HashOnType/oneOf",
+            &["Header", "Cookie", "API key", "Client IP"],
+        ),
         (
             "/components/schemas/SlsContentMode/oneOf",
             &["Metadata only", "Full content"],

crates/aisix-core/src/lib.rs

@@ -47,12 +47,13 @@ pub use models::{
     validate_rate_limit_policy, A2aAgent, A2aAuthType, A2aProtocolVersion, Adapter, AisixSnapshot,
     ApiKey, AppliedGuardrail, CachePolicy, CooldownConfig, ExporterKind, Guardrail,
     GuardrailExecution, GuardrailHookPoint, GuardrailKind, GuardrailMetricsSink,
-    GuardrailMonitorHit, KeywordConfig, KeywordPattern, McpAuthType, McpProtocolVersion,
-    McpRateLimit, McpServer, McpServerType, McpTransport, Model, ObservabilityExporter,
-    ParamConstraints, PassthroughAuthMode, PassthroughCredentialMode, PassthroughRoute,
-    PolicyScope, PolicyWindow, ProviderKey, RateLimit, RateLimitPolicy, RequestOverrides,
-    ResponseOverrides, Routing, RoutingStrategy, RoutingTarget, SchemaError, StreamDoneMarker,
-    TelemetryKind, TelemetryTags, WhenAllUnavailablePolicy, DEFAULT_COOLDOWN_TRIGGER_STATUSES,
+    GuardrailMonitorHit, HashOnSource, HashOnType, KeywordConfig, KeywordPattern, McpAuthType,
+    McpProtocolVersion, McpRateLimit, McpServer, McpServerType, McpTransport, Model,
+    ObservabilityExporter, ParamConstraints, PassthroughAuthMode, PassthroughCredentialMode,
+    PassthroughRoute, PolicyScope, PolicyWindow, ProviderKey, RateLimit, RateLimitPolicy,
+    RequestOverrides, ResponseOverrides, Routing, RoutingStrategy, RoutingTarget, SchemaError,
+    StreamDoneMarker, TelemetryKind, TelemetryTags, WhenAllUnavailablePolicy,
+    DEFAULT_COOLDOWN_TRIGGER_STATUSES,
 };
 pub use resource::{Resource, ResourceEntry};
 pub use snapshot::{ResourceTable, SnapshotHandle};

crates/aisix-core/src/models/mod.rs

@@ -76,7 +76,10 @@ pub use provider_key::{
 };
 pub use rate_limit::{McpRateLimit, RateLimit};
 pub use rate_limit_policy::{PolicyScope, PolicyWindow, RateLimitPolicy};
-pub use routing::{Routing, RoutingStrategy, RoutingTarget, WhenAllUnavailablePolicy};
+pub use routing::{
+    default_hash_on, HashOnSource, HashOnType, Routing, RoutingStrategy, RoutingTarget,
+    WhenAllUnavailablePolicy,
+};
 pub use schema::{
     validate_a2a_agent, validate_a2a_agent_lenient, validate_apikey, validate_apikey_lenient,
     validate_cache_policy, validate_cache_policy_lenient, validate_claim_mapping,