durability

Documentation

Overview

Package durability helps us to keep segments in healthy state with reporting risks.

Index

• type HealthStat
  • func (h *HealthStat) Merge(stat *HealthStat)
  • func (h *HealthStat) Min() int
  • func (h *HealthStat) Unused() bool
  • func (h *HealthStat) Update(num int, exemplar string)
• type NodeClassifier
• type ObserverFork
  • func (c *ObserverFork) Process(ctx context.Context, segments []rangedloop.Segment) (err error)
• type Report
  • func NewDurability(db overlay.DB, metabaseDB *metabase.DB, class string, ...) *Report
  • func (c *Report) Finish(ctx context.Context) error
  • func (c *Report) Fork(ctx context.Context) (rangedloop.Partial, error)
  • func (c *Report) GetClass() string
  • func (c *Report) Join(ctx context.Context, partial rangedloop.Partial) (err error)
  • func (c *Report) Start(ctx context.Context, startTime time.Time) (err error)
  • func (c *Report) TestChangeReporter(r func(n time.Time, class string, name string, stat *HealthStat))
• type ReportConfig

Types

type HealthStat

type HealthStat struct {
	Exemplar string
	// contains filtered or unexported fields
}

HealthStat collects the availability conditions for one class (for example: nodes with the same owner).

func (*HealthStat) Merge

func (h *HealthStat) Merge(stat *HealthStat)

Merge can merge two stat to one, without losing information.

func (*HealthStat) Min

func (h *HealthStat) Min() int

Min returns the minimal number.

func (*HealthStat) Unused

func (h *HealthStat) Unused() bool

Unused returns true when stat is uninitialized (-1) and was not updated with any number.

func (*HealthStat) Update

func (h *HealthStat) Update(num int, exemplar string)

Update updates the stat with one measurement: number of pieces which are available even without the nodes of the selected class. Exemplar is one example identifier with such measurement. Useful to dig deeper, based on this one example.

type NodeClassifier

type NodeClassifier func(node *nodeselection.SelectedNode) string

NodeClassifier identifies a risk class (for example an owner, or country) of the SelectedNode.

type ObserverFork

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

ObserverFork is the durability calculator for each segment range.

func (*ObserverFork) Process

func (c *ObserverFork) Process(ctx context.Context, segments []rangedloop.Segment) (err error)

Process implements rangedloop.Partial.

type Report

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

Report is a calculator (rangloop.Observer) which checks the availability of pieces without certain nodes. It can answer the following question:

1. loosing a given group of nodes (all nodes of one country or all nodes of one owner)...
2. what will be the lowest humber of healhty pieces, checking all the segments.

Example: we have one segment where 80 pieces are stored, but 42 of them are in Germany.

in this case this reporter will return 38 for the class "country:DE" (assuming all the other segments are more lucky).

func NewDurability

func NewDurability(db overlay.DB, metabaseDB *metabase.DB, class string, classifier NodeClassifier, maxPieceCount int, reportThreshold int, busFactorThreshold int, asOfSystemInterval time.Duration) *Report

NewDurability creates the new instance.

func (*Report) Finish

func (c *Report) Finish(ctx context.Context) error

Finish implements rangedloop.Observer.

func (*Report) Fork

func (c *Report) Fork(ctx context.Context) (rangedloop.Partial, error)

Fork implements rangedloop.Observer.

func (*Report) GetClass

func (c *Report) GetClass() string

GetClass return with the class instance name (like last_net or country).

func (*Report) Join

func (c *Report) Join(ctx context.Context, partial rangedloop.Partial) (err error)

Join implements rangedloop.Observer.

func (*Report) Start

func (c *Report) Start(ctx context.Context, startTime time.Time) (err error)

Start implements rangedloop.Observer.

func (*Report) TestChangeReporter

func (c *Report) TestChangeReporter(r func(n time.Time, class string, name string, stat *HealthStat))

TestChangeReporter modifies the reporter for unit tests.

type ReportConfig

type ReportConfig struct {
	Enabled bool `help:"whether to enable durability report (rangedloop observer)" default:"true"`
}

ReportConfig configures durability report.