Documentation
¶
Overview ¶
Dynamic weighted round robin load balancer
Index ¶
- Constants
- type EndpointOptions
- type EndpointWeight
- type FSMHandler
- type FailureHandler
- type Options
- type RoundRobin
- func (rr *RoundRobin) AddEndpoint(endpoint endpoint.Endpoint) error
- func (r *RoundRobin) AddEndpointWithOptions(endpoint endpoint.Endpoint, options EndpointOptions) error
- func (r *RoundRobin) FindEndpointById(id string) *WeightedEndpoint
- func (r *RoundRobin) FindEndpointByUrl(url string) *WeightedEndpoint
- func (r *RoundRobin) GetEndpoints() []*WeightedEndpoint
- func (r *RoundRobin) NextEndpoint(req request.Request) (endpoint.Endpoint, error)
- func (rr *RoundRobin) ObserveRequest(request.Request)
- func (rr *RoundRobin) ObserveResponse(req request.Request, a request.Attempt)
- func (rr *RoundRobin) ProcessRequest(request.Request) (*http.Response, error)
- func (rr *RoundRobin) ProcessResponse(req request.Request, a request.Attempt)
- func (r *RoundRobin) RemoveEndpoint(endpoint endpoint.Endpoint) error
- type SuggestedWeight
- type WeightedEndpoint
- func (we *WeightedEndpoint) GetEffectiveWeight() int
- func (we *WeightedEndpoint) GetId() string
- func (we *WeightedEndpoint) GetMeter() metrics.FailRateMeter
- func (we *WeightedEndpoint) GetOriginalEndpoint() endpoint.Endpoint
- func (we *WeightedEndpoint) GetOriginalWeight() int
- func (we *WeightedEndpoint) GetUrl() *url.URL
- func (we *WeightedEndpoint) String() string
- type WeightedEndpoints
Constants ¶
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const ( // This is the maximum weight that handler will set for the endpoint FSMMaxWeight = 4096 // Multiplier for the endpoint weight FSMGrowFactor = 16 )
Variables ¶
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Functions ¶
This section is empty.
Types ¶
type EndpointOptions ¶
type EndpointOptions struct {
// Relative weight for the enpoint to other enpoints in the load balancer
Weight int
// Meter tracks the failure count and is used to do failover
Meter metrics.FailRateMeter
}
Set additional parameters for the endpoint can be supplied when adding endpoint
type EndpointWeight ¶
type EndpointWeight struct {
Endpoint *WeightedEndpoint
Weight int
}
func (*EndpointWeight) GetEndpoint ¶
func (ew *EndpointWeight) GetEndpoint() *WeightedEndpoint
func (*EndpointWeight) GetWeight ¶
func (ew *EndpointWeight) GetWeight() int
func (*EndpointWeight) SetWeight ¶
func (ew *EndpointWeight) SetWeight(w int)
type FSMHandler ¶
type FSMHandler struct {
// contains filtered or unexported fields
}
This handler increases weights on endpoints that perform better than others it also rolls back to original weights if the endpoints have changed.
func NewFSMHandler ¶
func NewFSMHandler() (*FSMHandler, error)
func NewFSMHandlerWithOptions ¶
func NewFSMHandlerWithOptions(timeProvider timetools.TimeProvider) (*FSMHandler, error)
func (*FSMHandler) AdjustWeights ¶
func (fsm *FSMHandler) AdjustWeights() ([]SuggestedWeight, error)
Called on every load balancer NextEndpoint call, returns the suggested weights on every call, can adjust weights if needed.
func (*FSMHandler) Init ¶
func (fsm *FSMHandler) Init(endpoints []*WeightedEndpoint)
type FailureHandler ¶
type FailureHandler interface {
// Returns error if something bad happened, returns suggested weights
AdjustWeights() ([]SuggestedWeight, error)
// Initializes handler with current set of endpoints. Will be called
// each time endpoints are added or removed from the load balancer
// to give failure handler a chance to set it's itenral state
Init(endpoints []*WeightedEndpoint)
}
type Options ¶
type Options struct {
// Control time in tests
TimeProvider timetools.TimeProvider
// Algorithm that reacts on the failures and can adjust weights
FailureHandler FailureHandler
}
type RoundRobin ¶
type RoundRobin struct {
// contains filtered or unexported fields
}
Dynamic weighted round robin load balancer.
func NewRoundRobin ¶
func NewRoundRobin() (*RoundRobin, error)
func NewRoundRobinWithOptions ¶
func NewRoundRobinWithOptions(o Options) (*RoundRobin, error)
func (*RoundRobin) AddEndpoint ¶
func (rr *RoundRobin) AddEndpoint(endpoint endpoint.Endpoint) error
func (*RoundRobin) AddEndpointWithOptions ¶
func (r *RoundRobin) AddEndpointWithOptions(endpoint endpoint.Endpoint, options EndpointOptions) error
In case if endpoint is already present in the load balancer, returns error
func (*RoundRobin) FindEndpointById ¶
func (r *RoundRobin) FindEndpointById(id string) *WeightedEndpoint
func (*RoundRobin) FindEndpointByUrl ¶
func (r *RoundRobin) FindEndpointByUrl(url string) *WeightedEndpoint
func (*RoundRobin) GetEndpoints ¶
func (r *RoundRobin) GetEndpoints() []*WeightedEndpoint
func (*RoundRobin) NextEndpoint ¶
func (*RoundRobin) ObserveRequest ¶
func (rr *RoundRobin) ObserveRequest(request.Request)
func (*RoundRobin) ObserveResponse ¶
func (rr *RoundRobin) ObserveResponse(req request.Request, a request.Attempt)
func (*RoundRobin) ProcessRequest ¶
func (*RoundRobin) ProcessResponse ¶
func (rr *RoundRobin) ProcessResponse(req request.Request, a request.Attempt)
func (*RoundRobin) RemoveEndpoint ¶
func (r *RoundRobin) RemoveEndpoint(endpoint endpoint.Endpoint) error
type SuggestedWeight ¶
type SuggestedWeight interface {
GetEndpoint() *WeightedEndpoint
GetWeight() int
SetWeight(int)
}
type WeightedEndpoint ¶
type WeightedEndpoint struct {
// contains filtered or unexported fields
}
WeightedEndpoint wraps the endpoint and adds support for weights and failure detection.
func (*WeightedEndpoint) GetEffectiveWeight ¶
func (we *WeightedEndpoint) GetEffectiveWeight() int
func (*WeightedEndpoint) GetId ¶
func (we *WeightedEndpoint) GetId() string
func (*WeightedEndpoint) GetMeter ¶
func (we *WeightedEndpoint) GetMeter() metrics.FailRateMeter
func (*WeightedEndpoint) GetOriginalEndpoint ¶
func (we *WeightedEndpoint) GetOriginalEndpoint() endpoint.Endpoint
func (*WeightedEndpoint) GetOriginalWeight ¶
func (we *WeightedEndpoint) GetOriginalWeight() int
func (*WeightedEndpoint) GetUrl ¶
func (we *WeightedEndpoint) GetUrl() *url.URL
func (*WeightedEndpoint) String ¶
func (we *WeightedEndpoint) String() string
type WeightedEndpoints ¶
type WeightedEndpoints []*WeightedEndpoint
func (WeightedEndpoints) Len ¶
func (we WeightedEndpoints) Len() int
func (WeightedEndpoints) Less ¶
func (we WeightedEndpoints) Less(i, j int) bool
func (WeightedEndpoints) Swap ¶
func (we WeightedEndpoints) Swap(i, j int)
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