cluster

Documentation

Index

• type Cluster
  • func New(nodes node.ServiceNodes, opts Options) (Cluster, error)
• type Configuration
  • func (c *Configuration) Options(iopts instrument.Options) Options
• type Options
  • func NewOptions(placementSvc placement.Service, iopts instrument.Options) Options
• type Status

Types

type Cluster

type Cluster interface {
	// Setup sets up the service placement for the specified numNodes.
	Setup(numNodes int) ([]node.ServiceNode, error)

	// Teardown releases the resources acquired during Setup().
	Teardown() error

	// AddNode adds a node to the service placement. The node to add is chosen from
	// amongst // available spares, by the placementservice. It does NOT alter the
	// state of the ServiceNode (i.e. does not start/stop it).
	AddNode() (node.ServiceNode, error)

	// AddSpecifiedNode adds the specified node to the service placement. It does
	// NOT alter the state of the ServiceNode (i.e. does not start/stop it).
	AddSpecifiedNode(node.ServiceNode) error

	// RemoveNode removes the specified node from the service placement. It does
	// NOT alter the state of the ServiceNode (i.e. does not start/stop it).
	RemoveNode(node.ServiceNode) error

	// ReplaceNode replaces the specified node with new node(s) in the service
	// placement. It does NOT alter the state of the ServiceNode (i.e. does not start/stop it).
	ReplaceNode(oldNode node.ServiceNode) ([]node.ServiceNode, error)

	// Start starts all nodes used in current service placement.
	Start() error

	// Stop stops all nodes used in current service placement.
	Stop() error

	// SpareNodes returns the list of known nodes which are not part of the defined placement
	// in the cluster.
	SpareNodes() []node.ServiceNode

	// ActiveNodes returns the list of known nodes which are part of the defined placement
	// in the cluster.
	ActiveNodes() []node.ServiceNode

	// KnownNodes returns the list of known nodes
	KnownNodes() []node.ServiceNode

	// Placement returns the current placement
	Placement() placement.Placement

	// Status returns the cluster status
	Status() Status
}

Cluster is a collection of ServiceNodes with a m3cluster Placement

func New

func New(
	nodes node.ServiceNodes,
	opts Options,
) (Cluster, error)

New returns a new cluster backed by provided service nodes

type Configuration

type Configuration struct {
	SessionToken            *string               `yaml:"sessionToken"`
	SessionOverride         *bool                 `yaml:"sessionOverride"`
	Relication              *int                  `yaml:"replication"`
	NumShards               *int                  `yaml:"numShards"`
	PlacementServiceRetrier *xretry.Configuration `yaml:"placementServiceRetrier"`
	NodeConcurrency         *int                  `yaml:"nodeConcurrency"`
	NodeOperationTimeout    *time.Duration        `yaml:"nodeOperationTimeout"`
}

Configuration is a YAML wrapper around Options

func (*Configuration) Options

func (c *Configuration) Options(iopts instrument.Options) Options

Options returns `Options` corresponding to the provided struct values

type Options

type Options interface {
	// Validate validates the Options
	Validate() error

	// SetInstrumentOptions sets the instrumentation options
	SetInstrumentOptions(instrument.Options) Options

	// InstrumentOptions returns the instrumentation options
	InstrumentOptions() instrument.Options

	// SetServiceBuild sets the service build used to configure
	// the cluster
	SetServiceBuild(build.ServiceBuild) Options

	// ServiceBuild returns the service build used in the cluster
	ServiceBuild() build.ServiceBuild

	// SetServiceConfig sets the default service configuration to
	// be used in setting up the cluster
	SetServiceConfig(build.ServiceConfiguration) Options

	// ServiceConfig returns the default service configuration to
	// used in setting up the cluster
	ServiceConfig() build.ServiceConfiguration

	// SetSessionToken sets the token used for interactions with remote m3em agents
	SetSessionToken(string) Options

	// SessionToken returns the token used for interactions with remote m3em agents
	SessionToken() string

	// SetSessionOverride sets a flag indicating if m3em agent operations
	// are permitted to override clashing resources
	SetSessionOverride(bool) Options

	// SessionOverride returns a flag indicating if m3em agent operations
	// are permitted to override clashing resources
	SessionOverride() bool

	// SetReplication sets the replication factor for the cluster
	SetReplication(int) Options

	// Replication returns the replication factor by the cluster
	Replication() int

	// SetNumShards sets the number of shards used in the cluster
	SetNumShards(int) Options

	// NumShards returns the number of shards used in the cluster
	NumShards() int

	// SetPlacementService returns the PlacementService to use for cluster
	// configuration
	SetPlacementService(placement.Service) Options

	// PlacementService returns the PlacementService to use for cluster
	// configuration
	PlacementService() placement.Service

	// SetPlacementServiceRetrier sets the retrier to use for placement
	// service operations
	SetPlacementServiceRetrier(xretry.Retrier) Options

	// PlacementServiceRetrier returns the retrier to use for placement
	// service operations
	PlacementServiceRetrier() xretry.Retrier

	// SetNodeConcurrency sets the number of nodes to operate upon
	// concurrently
	SetNodeConcurrency(int) Options

	// NodeConcurrency returns the number of nodes to operate upon
	// concurrently
	NodeConcurrency() int

	// SetNodeOperationTimeout sets the timeout for a node operation
	SetNodeOperationTimeout(time.Duration) Options

	// NodeOperationTimeout returns the timeout for a node operation
	NodeOperationTimeout() time.Duration

	// SetNodeListener sets default node listener
	SetNodeListener(node.Listener) Options

	// NodeListener returns the node listener
	NodeListener() node.Listener
}

Options represents the options to configure a `Cluster`

func NewOptions

func NewOptions(
	placementSvc placement.Service,
	iopts instrument.Options,
) Options

NewOptions returns a new Options object

type Status

type Status int

Status indicates the different states a Cluster can be in. Refer to the state diagram below to understand transitions. Note, all states can transition to `ClusterStatusError`, these edges are skipped below.

       ╔══════════════════╗
       ║                  ║
       ║  Uninitialized   ║────────────Setup()────┐
       ║                  ║                       │
       ╚══════════════════╝                       │
                 ▲                                │
                 │                                │
                 │                                │
                 │   Teardown()                   │
                 ├────────────────────────┐       │
                 │                        │       │
         ┌───────┘                        │       │
         │                                │       ▼
   ╔═════╩════════════╗◀────Start()─────╦═╩════════════════╗
   ║                  ║                 ║                  ║
┌──║     Running      ║                 ║      Setup       ║──┐
│  ║                  ║                 ║                  ║  │
│  ╚══════════════════╝──────Stop()────▶╚══════════════════╝  │

AddInstance() ▲ ▲ AddInstance() RemoveInstance() │ │ RemoveInstance() ReplaceInstance()──┘ └────ReplaceInstance()

const (
	// ClusterStatusUninitialized refers to the state of an un-initialized cluster.
	ClusterStatusUninitialized Status = iota

	// ClusterStatusSetup refers to the state of a cluster whose nodes have
	// been setup, and the cluster has an assigned placement.
	ClusterStatusSetup

	// ClusterStatusRunning refers to the state of a cluster with running nodes.
	// There is no restriction on the number of nodes running, or assigned within
	// the cluster placement.
	ClusterStatusRunning

	// ClusterStatusError refers to a cluster in error.
	ClusterStatusError
)