skywalking-java/docs/en/setup/backend/dynamic-config.md

Dynamic Configuration

SkyWalking Configurations are mostly set through application.yml and OS system environment variables. At the same time, some of them support dynamic settings from upstream management system.

Currently, SkyWalking supports the following dynamic configurations.

Config Key	Value Description	Value Format Example
agent-analyzer.default.slowDBAccessThreshold	Thresholds of slow Database statement. Overrides receiver-trace/default/slowDBAccessThreshold of application.yml.	default:200,mongodb:50
agent-analyzer.default.uninstrumentedGateways	The uninstrumented gateways. Overrides gateways.yml.	Same as gateways.yml.
alarm.default.alarm-settings	The alarm settings. Overrides alarm-settings.yml.	Same as alarm-settings.yml.
core.default.apdexThreshold	The apdex threshold settings. Overrides service-apdex-threshold.yml.	Same as service-apdex-threshold.yml.
core.default.endpoint-name-grouping	The endpoint name grouping setting. Overrides endpoint-name-grouping.yml.	Same as endpoint-name-grouping.yml.
core.default.log4j-xml	The log4j xml configuration. Overrides log4j2.xml.	Same as log4j2.xml.
agent-analyzer.default.sampleRate	Trace sampling. Overrides receiver-trace/default/sampleRate of application.yml.	10000
agent-analyzer.default.slowTraceSegmentThreshold	Setting this threshold on latency (in milliseconds) would cause slow trace segments to be sampled if they use up more time, even if the sampling mechanism is activated. The default value is -1, which means slow traces will not be sampled. Overrides receiver-trace/default/slowTraceSegmentThreshold of application.yml.	-1
configuration-discovery.default.agentConfigurations	The ConfigurationDiscovery settings.	See configuration-discovery.md.

This feature depends on upstream service, so it is DISABLED by default.

configuration:
  selector: ${SW_CONFIGURATION:none}
  none:
  grpc:
    host: ${SW_DCS_SERVER_HOST:""}
    port: ${SW_DCS_SERVER_PORT:80}
    clusterName: ${SW_DCS_CLUSTER_NAME:SkyWalking}
    period: ${SW_DCS_PERIOD:20}
  # ... other implementations

Dynamic Configuration Service, DCS

Dynamic Configuration Service is a gRPC service which requires implementation of the upstream system. The SkyWalking OAP fetches the configuration from the implementation (any system), after you open the implementation like this:

configuration:
  selector: ${SW_CONFIGURATION:grpc}
  grpc:
    host: ${SW_DCS_SERVER_HOST:""}
    port: ${SW_DCS_SERVER_PORT:80}
    clusterName: ${SW_DCS_CLUSTER_NAME:SkyWalking}
    period: ${SW_DCS_PERIOD:20}

Dynamic Configuration Zookeeper Implementation

Zookeeper is also supported as Dynamic Configuration Center (DCC). To use it, please configure as follows:

configuration:
  selector: ${SW_CONFIGURATION:zookeeper}
  zookeeper:
    period: ${SW_CONFIG_ZK_PERIOD:60} # Unit seconds, sync period. Default fetch every 60 seconds.
    nameSpace: ${SW_CONFIG_ZK_NAMESPACE:/default}
    hostPort: ${SW_CONFIG_ZK_HOST_PORT:localhost:2181}
    # Retry Policy
    baseSleepTimeMs: ${SW_CONFIG_ZK_BASE_SLEEP_TIME_MS:1000} # initial amount of time to wait between retries
    maxRetries: ${SW_CONFIG_ZK_MAX_RETRIES:3} # max number of times to retry

The nameSpace is the ZooKeeper path. The config key and value are the properties of the namespace folder.

Dynamic Configuration Etcd Implementation

Etcd is also supported as Dynamic Configuration Center (DCC). To use it, please configure as follows:

configuration:
  selector: ${SW_CONFIGURATION:etcd}
  etcd:
    period: ${SW_CONFIG_ETCD_PERIOD:60} # Unit seconds, sync period. Default fetch every 60 seconds.
    endpoints: ${SW_CONFIG_ETCD_ENDPOINTS:localhost:2379}
    namespace: ${SW_CONFIG_ETCD_NAMESPACE:/skywalking}
    authentication: ${SW_CONFIG_ETCD_AUTHENTICATION:false}
    user: ${SW_CONFIG_ETCD_USER:}
    password: ${SW_CONFIG_ETCD_password:}

NOTE: Only the v3 protocol is supported since 8.7.0.

Dynamic Configuration Consul Implementation

Consul is also supported as Dynamic Configuration Center (DCC). To use it, please configure as follows:

configuration:
  selector: ${SW_CONFIGURATION:consul}
  consul:
    # Consul host and ports, separated by comma, e.g. 1.2.3.4:8500,2.3.4.5:8500
    hostAndPorts: ${SW_CONFIG_CONSUL_HOST_AND_PORTS:1.2.3.4:8500}
    # Sync period in seconds. Defaults to 60 seconds.
    period: ${SW_CONFIG_CONSUL_PERIOD:1}
    # Consul aclToken
    aclToken: ${SW_CONFIG_CONSUL_ACL_TOKEN:""}

Dynamic Configuration Apollo Implementation

Apollo is also supported as Dynamic Configuration Center (DCC). To use it, please configure as follows:

configuration:
  selector: ${SW_CONFIGURATION:apollo}
  apollo:
    apolloMeta: ${SW_CONFIG_APOLLO:http://106.12.25.204:8080}
    apolloCluster: ${SW_CONFIG_APOLLO_CLUSTER:default}
    apolloEnv: ${SW_CONFIG_APOLLO_ENV:""}
    appId: ${SW_CONFIG_APOLLO_APP_ID:skywalking}
    period: ${SW_CONFIG_APOLLO_PERIOD:5}

Dynamic Configuration Kuberbetes Configmap Implementation

configmap is also supported as Dynamic Configuration Center (DCC). To use it, please configure as follows:

configuration:
  selector: ${SW_CONFIGURATION:k8s-configmap}
  # [example] (../../../../oap-server/server-configuration/configuration-k8s-configmap/src/test/resources/skywalking-dynamic-configmap.example.yaml)
  k8s-configmap:
      # Sync period in seconds. Defaults to 60 seconds.
      period: ${SW_CONFIG_CONFIGMAP_PERIOD:60}
      # Which namespace is confiigmap deployed in.
      namespace: ${SW_CLUSTER_K8S_NAMESPACE:default}
      # Labelselector is used to locate specific configmap
      labelSelector: ${SW_CLUSTER_K8S_LABEL:app=collector,release=skywalking}

Dynamic Configuration Nacos Implementation

Nacos is also supported as Dynamic Configuration Center (DCC). To use it, please configure as follows:

configuration:
  selector: ${SW_CONFIGURATION:nacos}
  nacos:
    # Nacos Server Host
    serverAddr: ${SW_CONFIG_NACOS_SERVER_ADDR:127.0.0.1}
    # Nacos Server Port
    port: ${SW_CONFIG_NACOS_SERVER_PORT:8848}
    # Nacos Configuration Group
    group: ${SW_CONFIG_NACOS_SERVER_GROUP:skywalking}
    # Nacos Configuration namespace
    namespace: ${SW_CONFIG_NACOS_SERVER_NAMESPACE:}
    # Unit seconds, sync period. Default fetch every 60 seconds.
    period: ${SW_CONFIG_NACOS_PERIOD:60}
    # the name of current cluster, set the name if you want to upstream system known.
    clusterName: ${SW_CONFIG_NACOS_CLUSTER_NAME:default}