How to configure traffic routing

    After installation, you can see that the following two NSs have been added to the cluster, and the Dubbo and Thrift demo applications are installed in these two NSs. You can choose either of them to test.

    Istio uses TCP proxy to proxy non-HTTP client requests, and all requests from the same client TCP connection are sent to a single server instance. This leads to some problems: when clients use long connections, multiple server instances do not receive a balanced number of requests. Furthermore, when the server side is overloaded, the incoming requests that come into the existing connections can’t be redistributed to new server instances even though more instances are added to the pool of the server cluster to share the load.

    Aeraki supports layer-7(request level) load balancing for any protocols developed based on MetaProtocol, so the client-side sidecar proxy sends requests evenly to these two server instances, enven though the client is using a single long TCP connection to connect to the server.

    Let’s use the aerakictl command to view the client-side log, you’ll see that client requests are sent to two server pods in turn, v1 and v2, like the following:

    2. Hello Aeraki, response from thrift-sample-server-v2-6d5bcc885-wglpc/172.17.0.93
    3. Hello Aeraki, response from thrift-sample-server-v1-5c8476684-hr8hh/172.17.0.92
    4. Hello Aeraki, response from thrift-sample-server-v2-6d5bcc885-wglpc/172.17.0.93
    5. Hello Aeraki, response from thrift-sample-server-v1-5c8476684-hr8hh/172.17.0.92
    6. Hello Aeraki, response from thrift-sample-server-v2-6d5bcc885-wglpc/172.17.0.93
    7. Hello Aeraki, response from thrift-sample-server-v1-5c8476684-hr8hh/172.17.0.92

    Create a MetaRouter routing rule that routes the request to v1.

    1. kubectl apply -f- <<EOF
    2. apiVersion: metaprotocol.aeraki.io/v1alpha1
    3. kind: MetaRouter
    4. metadata:
    5.   name: test-metaprotocol-thrift-route
    6.   namespace: meta-thrift
    7. spec:
    8.   hosts:
    9.     - thrift-sample-server.meta-thrift.svc.cluster.local
    10.   routes:
    11.     - name: v1
    12.       match:
    13.         attributes:
    14.           method:
    15.             exact: sayHello
    16.       route:
    17.         - destination:
    18.             host: thrift-sample-server.meta-thrift.svc.cluster.local
    19.             subset: v1
    20. EOF

    Using the aerakictl command to view the client-side log, you can see that all requests from the client are routed to the v1 version.

    Use MetaRouter routing rules to send client requests to different versions of the service in specified proportions.

    1. kubectl apply -f- <<EOF
    2. apiVersion: metaprotocol.aeraki.io/v1alpha1
    3. kind: MetaRouter
    4. metadata:
    5.   name: test-metaprotocol-thrift-route
    6.   namespace: meta-thrift
    7. spec:
    8.   hosts:
    9.     - thrift-sample-server.meta-thrift.svc.cluster.local
    10.   routes:
    11.     - name: traffic-split
    12.       match:
    13.         attributes:
    14.           method:
    15.             exact: sayHello
    16.         - destination:
    17.             host: thrift-sample-server.meta-thrift.svc.cluster.local
    18.             subset: v1
    20.         - destination:
    21.             host: thrift-sample-server.meta-thrift.svc.cluster.local
    22.             subset: v2
    23.           weight: 80
    24. EOF
    1. ➜  ~ aerakictl_app_log client meta-thrift -f --tail 10
    2. Hello Aeraki, response from thrift-sample-server-v2-6d5bcc885-wglpc/172.17.0.93
    3. Hello Aeraki, response from thrift-sample-server-v2-6d5bcc885-wglpc/172.17.0.93
    4. Hello Aeraki, response from thrift-sample-server-v2-6d5bcc885-wglpc/172.17.0.93
    5. Hello Aeraki, response from thrift-sample-server-v2-6d5bcc885-wglpc/172.17.0.93
    6. Hello Aeraki, response from thrift-sample-server-v2-6d5bcc885-wglpc/172.17.0.93
    7. Hello Aeraki, response from thrift-sample-server-v2-6d5bcc885-wglpc/172.17.0.93
    8. Hello Aeraki, response from thrift-sample-server-v2-6d5bcc885-wglpc/172.17.0.93
    9. Hello Aeraki, response from thrift-sample-server-v2-6d5bcc885-wglpc/172.17.0.93
    10. Hello Aeraki, response from thrift-sample-server-v1-6d5bcc885-wglpc/172.17.0.93
    11. Hello Aeraki, response from thrift-sample-server-v1-5c8476684-hr8hh/172.17.0.92

    In the configuration sent to the Sidecar Proxy, Aeraki sets up the MetaProtocol Proxy in the FilterChain of the Outbound Listener corresponding to the service, and specifies Aeraki as the RDS server in the MetaProtocol Proxy configuration.

    Aeraki translates MetaRouter to MetaProtocol route configuration, and then distributes them to the MetaProtocol Proxy through Aeraki’s built-in RDS server.

    The configuration of the sidecar proxy can be viewed with the following command:

    The configuration of the MetaProtocol Proxy in the Outbound Listener of the Thrift service is shown below.

    1. {
    2.  "name": "envoy.filters.network.meta_protocol_proxy",
    3.  "typed_config": {
    4.   "@type": "type.googleapis.com/udpa.type.v1.TypedStruct",
    5.   "type_url": "type.googleapis.com/aeraki.meta_protocol_proxy.v1alpha.MetaProtocolProxy",
    6.   "value": {
    7.    "stat_prefix": "outbound|9090||thrift-sample-server.meta-thrift.svc.cluster.local",
    8.    "application_protocol": "thrift",
    9.    "rds": {
    10.     "config_source": {
    11.      "api_config_source": {
    12.       "api_type": "GRPC",
    13.       "grpc_services": [
    14.        {
    15.         "envoy_grpc": {
    16.          "cluster_name": "aeraki-xds"
    17.         }
    18.        }
    19.       ],
    20.       "transport_api_version": "V3"
    21.      },
    22.      "resource_api_version": "V3"
    23.     },
    24.     "route_config_name": "thrift-sample-server.meta-thrift.svc.cluster.local_9090"
    25.    },
    26.    "codec": {
    27.     "name": "aeraki.meta_protocol.codec.thrift"
    28.    "meta_protocol_filters": [
    30.      "name": "aeraki.meta_protocol.filters.router"
    31.     }
    32.    ]
    33.   }
    34.  }
    35. }
    1. {
    2. @type": "type.googleapis.com/aeraki.meta_protocol_proxy.admin.v1alpha.RoutesConfigDump",
    3. dynamic_route_configs": [
    4. {
    5.  "version_info": "1641896797",
    6.  "route_config": {
    7.   "@type": "type.googleapis.com/aeraki.meta_protocol_proxy.config.route.v1alpha.RouteConfiguration",
    8.   "name": "thrift-sample-server.meta-thrift.svc.cluster.local_9090",
    9.   "routes": [
    10.    {
    11.     "name": "traffic-split",
    12.     "match": {
    13.      "metadata": [
    14.       {
    15.        "name": "method",
    16.        "exact_match": "sayHello"
    17.       }
    18.      ]
    19.     },
    20.     "route": {
    21.      "weighted_clusters": {
    22.       "clusters": [
    23.        {
    24.         "name": "outbound|9090|v1|thrift-sample-server.meta-thrift.svc.cluster.local",
    25.         "weight": 20
    26.        },
    27.        {
    28.         "name": "outbound|9090|v2|thrift-sample-server.meta-thrift.svc.cluster.local",
    29.         "weight": 80
    30.        }
    31.       ],
    32.       "total_weight": 100
    33.      }
    34.     }
    35.    }
    36.   ]
    37.  },
    38.  "last_updated": "2022-01-11T10:26:37.357Z"
    39. }

    Last modified May 9, 2022: Update routing.md (cede715)