Add locality loadbalance to kmesh workload mode.

bpf/kmesh/workload/include/service.h

@@ -17,9 +17,16 @@ static inline int lb_random_handle(struct kmesh_context *kmesh_ctx, __u32 servic
     int ret = 0;
     endpoint_key endpoint_k = {0};
     endpoint_value *endpoint_v = NULL;
+    int rand_k = 0;
+
+    if (service_v->prio_endpoint_count[0] == 0)
+        return 0;
 
     endpoint_k.service_id = service_id;
-    endpoint_k.backend_index = bpf_get_prandom_u32() % service_v->endpoint_count + 1;
+    endpoint_k.prio = 0; // for random handle，all endpoints are saved with highest priority
+
+    rand_k = bpf_get_prandom_u32() % service_v->prio_endpoint_count[0] + 1;
+    endpoint_k.backend_index = rand_k;
 
     endpoint_v = map_lookup_endpoint(&endpoint_k);
     if (!endpoint_v) {
@@ -37,6 +44,50 @@ static inline int lb_random_handle(struct kmesh_context *kmesh_ctx, __u32 servic
     return 0;
 }
 
+static inline int
+lb_locality_failover_handle(struct kmesh_context *kmesh_ctx, __u32 service_id, service_value *service_v, bool is_strict)
+{
+    int ret = 0;
+    uint32_t rand_k = 0;
+    endpoint_key endpoint_k = {0};
+    endpoint_value *endpoint_v = NULL;
+    endpoint_k.service_id = service_id;
+    struct ip_addr zero_addr = {0};
+    __u32 zero_port = 0;
+
+    // #pragma unroll
+    for (int match_prio = 0; match_prio < PRIO_COUNT; match_prio++) {
+        endpoint_k.prio = match_prio; // 0->6
+        // if we have endpoints in this prio
+        if (service_v->prio_endpoint_count[match_prio] > 0) {
+            rand_k = bpf_get_prandom_u32() % service_v->prio_endpoint_count[match_prio] + 1;
+            endpoint_k.backend_index = rand_k;
+            endpoint_v = map_lookup_endpoint(&endpoint_k);
+            if (!endpoint_v) {
+                BPF_LOG(
+                    ERR, SERVICE, "find endpoint [%u/%u/%u] failed", service_id, match_prio, endpoint_k.backend_index);
+                return -ENOENT;
+            }
+            ret = endpoint_manager(kmesh_ctx, endpoint_v, service_id, service_v);
+            if (ret != 0) {
+                if (ret != -ENOENT)
+                    BPF_LOG(ERR, SERVICE, "endpoint_manager failed, ret:%d\n", ret);
+                return ret;
+            }
+            BPF_LOG(DEBUG, SERVICE, "locality loadbalance matched backend_uid %d\n", endpoint_v->backend_uid);
+            return 0; // find the backend successfully
+        }
+        if (is_strict) { // only match max priority in strict mode
+            kmesh_ctx->dnat_ip = zero_addr;
+            kmesh_ctx->dnat_port = zero_port;
+            BPF_LOG(DEBUG, SERVICE, "locality loadbalance match nothing in STRICT mode\n");
+            return -ENOENT;
+        }
+    }
+    // no backend matched
+    return -ENOENT;
+}
+
 static inline int service_manager(struct kmesh_context *kmesh_ctx, __u32 service_id, service_value *service_v)
 {
     int ret = 0;
@@ -55,15 +106,18 @@ static inline int service_manager(struct kmesh_context *kmesh_ctx, __u32 service
         return ret;
     }
 
-    if (service_v->endpoint_count == 0) {
-        BPF_LOG(DEBUG, SERVICE, "service %u has no endpoint", service_id);
-        return 0;
-    }
+    BPF_LOG(DEBUG, SERVICE, "service [%u] policy [%u] failed", service_id, service_v->lb_policy);
 
     switch (service_v->lb_policy) {
     case LB_POLICY_RANDOM:
         ret = lb_random_handle(kmesh_ctx, service_id, service_v);
         break;
+    case LB_POLICY_STRICT:
+        ret = lb_locality_failover_handle(kmesh_ctx, service_id, service_v, true);
+        break;
+    case LB_POLICY_FAILOVER:
+        ret = lb_locality_failover_handle(kmesh_ctx, service_id, service_v, false);
+        break;
     default:
         BPF_LOG(ERR, SERVICE, "unsupported load balance type:%u\n", service_v->lb_policy);
         ret = -EINVAL;

bpf/kmesh/workload/include/workload.h

@@ -10,6 +10,7 @@
 #define MAX_PORT_COUNT            10
 #define MAX_SERVICE_COUNT         10
 #define RINGBUF_SIZE              (1 << 12)
+#define PRIO_COUNT                7
 #define MAX_MEMBER_NUM_PER_POLICY 4
 
 #pragma pack(1)
@@ -28,8 +29,9 @@ typedef struct {
 } service_key;
 
 typedef struct {
-    __u32 endpoint_count;               // endpoint count of current service
-    __u32 lb_policy;                    // load balancing algorithm, currently only supports random algorithm
+    __u32 prio_endpoint_count[PRIO_COUNT]; // endpoint count of current service with prio
+    __u32 lb_policy; // load balancing algorithm, currently supports random algorithm, locality loadbalance
+                     // Failover/strict mode
     __u32 service_port[MAX_PORT_COUNT]; // service_port[i] and target_port[i] are a pair, i starts from 0 and max value
                                         // is MAX_PORT_COUNT-1
     __u32 target_port[MAX_PORT_COUNT];
@@ -40,6 +42,7 @@ typedef struct {
 // endpoint map
 typedef struct {
     __u32 service_id;    // service id
+    __u32 prio;          // 0 means heightest prio, match all scope, 6 means lowest prio.
     __u32 backend_index; // if endpoint_count = 3, then backend_index = 0/1/2
 } endpoint_key;
 

bpf/kmesh/workload/include/workload_common.h

@@ -22,6 +22,8 @@
 // loadbalance type
 typedef enum {
     LB_POLICY_RANDOM = 0,
+    LB_POLICY_STRICT = 1,
+    LB_POLICY_FAILOVER = 2,
 } lb_policy_t;
 
 #pragma pack(1)

pkg/controller/workload/bpfcache/endpoint.go

@@ -21,8 +21,13 @@
 	"istio.io/istio/pkg/util/sets"
 )
 
+const (
+	PrioCount = 7
+)
+
 type EndpointKey struct {
 	ServiceId    uint32 // service id
+	Prio         uint32
 	BackendIndex uint32 // if endpoint_count = 3, then backend_index = 1/2/3
 }
 
@@ -59,15 +64,17 @@
 }
 
 // EndpointSwap update the last endpoint index and remove the current endpoint
-func (c *Cache) EndpointSwap(currentIndex, lastIndex uint32, serviceId uint32) error {
+func (c *Cache) EndpointSwap(currentIndex, lastIndex uint32, serviceId uint32, prio uint32) error {
 	if currentIndex == lastIndex {
 		return c.EndpointDelete(&EndpointKey{
 			ServiceId:    serviceId,
+			Prio:         prio,
 			BackendIndex: lastIndex,
 		})
 	}
 	lastKey := &EndpointKey{
 		ServiceId:    serviceId,
+		Prio:         prio,
 		BackendIndex: lastIndex,
 	}
 	lastValue := &EndpointValue{}
@@ -77,6 +84,7 @@
 
 	currentKey := &EndpointKey{
 		ServiceId:    serviceId,
+		Prio:         prio,
 		BackendIndex: currentIndex,
 	}
 	currentValue := &EndpointValue{}

pkg/controller/workload/bpfcache/locality_cache.go

@@ -0,0 +1,100 @@
+/*
+ * Copyright The Kmesh Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package bpfcache
+
+import (
+	"sync"
+
+	"kmesh.net/kmesh/api/v2/workloadapi"
+)
+
+// localityInfo records local node workload locality info
+type localityInfo struct {
+	region    string // init from workload.GetLocality().GetRegion()
+	zone      string // init from workload.GetLocality().GetZone()
+	subZone   string // init from workload.GetLocality().GetSubZone()
+	nodeName  string // init from os.Getenv("NODE_NAME"), workload.GetNode()
+	clusterId string // init from workload.GetClusterId()
+	network   string // workload.GetNetwork()
+}
+
+type LocalityCache struct {
+	mutex        sync.RWMutex
+	LocalityInfo *localityInfo
+}
+
+func NewLocalityCache() LocalityCache {
+	return LocalityCache{
+		LocalityInfo: nil,
+	}
+}
+
+func (l *LocalityCache) SetLocality(nodeName, clusterId, network string, locality *workloadapi.Locality) {
+	l.mutex.Lock()
+	defer l.mutex.Unlock()
+	if l.LocalityInfo == nil {
+		l.LocalityInfo = &localityInfo{}
+	}
+
+	// notice: nodeName should set by processor or os.Getenv("NODE_NAME"),
+	l.LocalityInfo.region = locality.GetRegion()
+	l.LocalityInfo.zone = locality.GetZone()
+	l.LocalityInfo.subZone = locality.GetSubzone()
+	l.LocalityInfo.nodeName = nodeName
+	l.LocalityInfo.clusterId = clusterId
+	l.LocalityInfo.network = network
+}
+
+func (l *LocalityCache) CalcLocalityLBPrio(wl *workloadapi.Workload, rp []workloadapi.LoadBalancing_Scope) uint32 {
+	var rank uint32 = 0
+	for _, scope := range rp {
+		match := false
+		switch scope {
+		case workloadapi.LoadBalancing_REGION:
+			if l.LocalityInfo.region == wl.GetLocality().GetRegion() {
+				match = true
+			}
+		case workloadapi.LoadBalancing_ZONE:
+			if l.LocalityInfo.zone == wl.GetLocality().GetZone() {
+				match = true
+			}
+		case workloadapi.LoadBalancing_SUBZONE:
+			if l.LocalityInfo.subZone == wl.GetLocality().GetSubzone() {
+				match = true
+			}
+		case workloadapi.LoadBalancing_NODE:
+			if l.LocalityInfo.nodeName == wl.GetNode() {
+				match = true
+			}
+		case workloadapi.LoadBalancing_CLUSTER:
+			if l.LocalityInfo.clusterId == wl.GetClusterId() {
+				match = true
+			}
+		case workloadapi.LoadBalancing_NETWORK:
+			log.Debugf("l.LocalityInfo.network %#v, wl.GetNetwork() %#v", l.LocalityInfo.network, wl.GetNetwork())
+			if l.LocalityInfo.network == wl.GetNetwork() {
+				match = true
+			}
+		}
+		if match {
+			rank++
+		} else {
+			break
+		}
+	}
+	return uint32(len(rp)) - rank
+}