worker

README

Cadence Worker

Cadence Worker is a new role for Cadence service used for hosting any components responsible for performing background processing on the Cadence cluster.

Replicator

Replicator is a background worker responsible for consuming replication tasks generated by remote Cadence clusters and pass it down to processor so they can be applied to local Cadence cluster.

It uses Kafka as the replication tasks buffer and relies on [kafka-client library] (https://github.com/uber-go/kafka-client/) for consuming messages from Kafka.

Quickstart for localhost development

1. Setup Kafka by following instructions: Kafka Quickstart
2. Create Kafka topic for active cluster:

bin/kafka-topics.sh --create --zookeeper localhost:2181 --replication-factor 1 --partitions 1 --topic active

1. Create Kafka topic for standby cluster:

bin/kafka-topics.sh --create --zookeeper localhost:2181 --replication-factor 1 --partitions 1 --topic standby

1. Start Cadence development server for active zone:

./cadence-server --zone active start

Cadence cluster is now running with the replicator consuming messages from Kafka topic standby.

Create replication task using CLI

Kafka CLI can be used to generate a replication task for testing purpose:

bin/kafka-console-producer.sh --broker-list localhost:9092 --topic standby

Replication task message:

{taskType: 0}

Archiver

Archiver is used to handle archival of workflow execution histories. It does this by hosting a cadence client worker and running an archival system workflow. The archival client gets used to initiate archival through signal sending. The archiver shards work across several workflows.

Documentation

Index

• func NewService(params *service.BootstrapParams) common.Daemon
• type Config
  • func NewConfig(params *service.BootstrapParams) *Config
• type Service
  • func (s *Service) Start()
  • func (s *Service) Stop()

Functions

func NewService

func NewService(params *service.BootstrapParams) common.Daemon

NewService builds a new cadence-worker service

Types

type Config

type Config struct {
	ReplicationCfg  *replicator.Config
	ArchiverConfig  *archiver.Config
	IndexerCfg      *indexer.Config
	ScannerCfg      *scanner.Config
	ThrottledLogRPS dynamicconfig.IntPropertyFn
}

Config contains all the service config for worker

func NewConfig

func NewConfig(params *service.BootstrapParams) *Config

NewConfig builds the new Config for cadence-worker service

type Service

type Service struct {
	// contains filtered or unexported fields
}

Service represents the cadence-worker service. This service hosts all background processing needed for cadence cluster: 1. Replicator: Handles applying replication tasks generated by remote clusters. 2. Indexer: Handles uploading of visibility records to elastic search. 3. Archiver: Handles archival of workflow histories.

func (*Service) Start

func (s *Service) Start()

Start is called to start the service

func (*Service) Stop

func (s *Service) Stop()

Stop is called to stop the service