Cluster Management

In many product environments, backend needs to support high throughput and provides HA to keep robustness, so you should need cluster management always in product env.

Backend provides several ways to do cluster management. Choose the one you need/want.

  • Zookeeper coordinator. Use Zookeeper to let backend instance detects and communicates with each other.
  • Kubernetes. When backend cluster are deployed inside kubernetes, you could choose this by using k8s native APIs to manage cluster.
  • Consul. Use Consul as backend cluster management implementor, to coordinate backend instances.
  • Etcd. Use Etcd to coordinate backend instances.
  • Nacos. Use Nacos to coordinate backend instances. In the application.yml, there’re default configurations for the aforementioned coordinators under the section cluster, you can specify one of them in the selector property to enable it.

Zookeeper coordinator

Zookeeper is a very common and wide used cluster coordinator. Set the cluster/selector to zookeeper in the yml to enable.

Required Zookeeper version, 3.4+

cluster:
  selector: ${SW_CLUSTER:zookeeper}
  # other configurations
  • hostPort is the list of zookeeper servers. Format is IP1:PORT1,IP2:PORT2,...,IPn:PORTn
  • enableACL enable Zookeeper ACL to control access to its znode.
  • schema is Zookeeper ACL schemas.
  • expression is a expression of ACL. The format of the expression is specific to the schema.
  • hostPort, baseSleepTimeMs and maxRetries are settings of Zookeeper curator client.

Note:

  • If Zookeeper ACL is enabled and /skywalking existed, must be sure SkyWalking has CREATE, READ and WRITE permissions. If /skywalking is not exists, it will be created by SkyWalking and grant all permissions to the specified user. Simultaneously, znode is granted READ to anyone.
  • If set schema as digest, the password of expression is set in clear text.

In some cases, oap default gRPC host and port in core are not suitable for internal communication among the oap nodes. The following setting are provided to set the host and port manually, based on your own LAN env.

  • internalComHost, the host registered and other oap node use this to communicate with current node.
  • internalComPort, the port registered and other oap node use this to communicate with current node.
zookeeper:
  nameSpace: ${SW_NAMESPACE:""}
  hostPort: ${SW_CLUSTER_ZK_HOST_PORT:localhost:2181}
  #Retry Policy
  baseSleepTimeMs: ${SW_CLUSTER_ZK_SLEEP_TIME:1000} # initial amount of time to wait between retries
  maxRetries: ${SW_CLUSTER_ZK_MAX_RETRIES:3} # max number of times to retry
  internalComHost: 172.10.4.10
  internalComPort: 11800
  # Enable ACL
  enableACL: ${SW_ZK_ENABLE_ACL:false} # disable ACL in default
  schema: ${SW_ZK_SCHEMA:digest} # only support digest schema
  expression: ${SW_ZK_EXPRESSION:skywalking:skywalking}

Kubernetes

Require backend cluster are deployed inside kubernetes, guides are in Deploy in kubernetes. Set the selector to kubernetes.

cluster:
  selector: ${SW_CLUSTER:kubernetes}
  # other configurations

Consul

Now, consul is becoming a famous system, many of companies and developers using consul to be their service discovery solution. Set the cluster/selector to consul in the yml to enable.

cluster:
  selector: ${SW_CLUSTER:consul}
  # other configurations

Same as Zookeeper coordinator, in some cases, oap default gRPC host and port in core are not suitable for internal communication among the oap nodes. The following setting are provided to set the host and port manually, based on your own LAN env.

  • internalComHost, the host registered and other oap node use this to communicate with current node.
  • internalComPort, the port registered and other oap node use this to communicate with current node.

Etcd

Set the cluster/selector to etcd in the yml to enable.

cluster:
  selector: ${SW_CLUSTER:etcd}
  # other configurations

Same as Zookeeper coordinator, in some cases, oap default gRPC host and port in core are not suitable for internal communication among the oap nodes. The following setting are provided to set the host and port manually, based on your own LAN env.

  • internalComHost, the host registered and other oap node use this to communicate with current node.
  • internalComPort, the port registered and other oap node use this to communicate with current node.

Nacos

Set the cluster/selector to nacos in the yml to enable.

cluster:
  selector: ${SW_CLUSTER:nacos}
  # other configurations

Nacos support authenticate by username or accessKey, empty means no need auth. extra config is bellow:

nacos:
  username:
  password:
  accessKey:
  secretKey:

Same as Zookeeper coordinator, in some cases, oap default gRPC host and port in core are not suitable for internal communication among the oap nodes. The following setting are provided to set the host and port manually, based on your own LAN env.

  • internalComHost, the host registered and other oap node use this to communicate with current node.
  • internalComPort, the port registered and other oap node use this to communicate with current node.