storage

Documentation

Index

• type DiskMetricStore
  • func NewDiskMetricStore(persistenceFile string, persistenceInterval time.Duration, ...) *DiskMetricStore
  • func (dms *DiskMetricStore) GetMetricFamilies() []*dto.MetricFamily
  • func (dms *DiskMetricStore) GetMetricFamiliesMap() GroupingKeyToMetricGroup
  • func (dms *DiskMetricStore) Healthy() error
  • func (dms *DiskMetricStore) Ready() error
  • func (dms *DiskMetricStore) Shutdown() error
  • func (dms *DiskMetricStore) SubmitWriteRequest(req WriteRequest)
• type GobbableMetricFamily
  • func (gmf *GobbableMetricFamily) GobDecode(b []byte) error
  • func (gmf *GobbableMetricFamily) GobEncode() ([]byte, error)
• type GroupingKeyToMetricGroup
• type MetricGroup
  • func (mg MetricGroup) LastPushSuccess() bool
  • func (mg MetricGroup) SortedLabels() []string
• type MetricStore
• type NameToTimestampedMetricFamilyMap
• type TimestampedMetricFamily
  • func (tmf TimestampedMetricFamily) GetMetricFamily() *dto.MetricFamily
• type WriteRequest

Types

type DiskMetricStore

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

DiskMetricStore is an implementation of MetricStore that persists metrics to disk.

func NewDiskMetricStore

func NewDiskMetricStore(
	persistenceFile string,
	persistenceInterval time.Duration,
	gatherPredefinedHelpFrom prometheus.Gatherer,
	logger log.Logger,
) *DiskMetricStore

NewDiskMetricStore returns a DiskMetricStore ready to use. To cleanly shut it down and free resources, the Shutdown() method has to be called.

If persistenceFile is the empty string, no persisting to disk will happen. Otherwise, a file of that name is used for persisting metrics to disk. If the file already exists, metrics are read from it as part of the start-up. Persisting is happening upon shutdown and after every write action, but the latter will only happen persistenceDuration after the previous persisting.

If a non-nil Gatherer is provided, the help strings of metrics gathered by it will be used as standard. Pushed metrics with deviating help strings will be adjusted to avoid inconsistent expositions.

func (*DiskMetricStore) GetMetricFamilies

func (dms *DiskMetricStore) GetMetricFamilies() []*dto.MetricFamily

GetMetricFamilies implements the MetricStore interface.

func (*DiskMetricStore) GetMetricFamiliesMap

func (dms *DiskMetricStore) GetMetricFamiliesMap() GroupingKeyToMetricGroup

GetMetricFamiliesMap implements the MetricStore interface.

func (*DiskMetricStore) Healthy

func (dms *DiskMetricStore) Healthy() error

Healthy implements the MetricStore interface.

func (*DiskMetricStore) Ready

func (dms *DiskMetricStore) Ready() error

Ready implements the MetricStore interface.

func (*DiskMetricStore) Shutdown

func (dms *DiskMetricStore) Shutdown() error

Shutdown implements the MetricStore interface.

func (*DiskMetricStore) SubmitWriteRequest

func (dms *DiskMetricStore) SubmitWriteRequest(req WriteRequest)

SubmitWriteRequest implements the MetricStore interface.

type GobbableMetricFamily

type GobbableMetricFamily dto.MetricFamily

GobbableMetricFamily is a dto.MetricFamily that implements GobDecoder and GobEncoder.

func (*GobbableMetricFamily) GobDecode

func (gmf *GobbableMetricFamily) GobDecode(b []byte) error

GobDecode implements gob.GobDecoder.

func (*GobbableMetricFamily) GobEncode

func (gmf *GobbableMetricFamily) GobEncode() ([]byte, error)

GobEncode implements gob.GobEncoder.

type GroupingKeyToMetricGroup

type GroupingKeyToMetricGroup map[string]MetricGroup

GroupingKeyToMetricGroup is the first level of the metric store, keyed by grouping key.

type MetricGroup

type MetricGroup struct {
	Labels  map[string]string
	Metrics NameToTimestampedMetricFamilyMap
}

MetricGroup adds the grouping labels to a NameToTimestampedMetricFamilyMap.

func (MetricGroup) LastPushSuccess

func (mg MetricGroup) LastPushSuccess() bool

LastPushSuccess returns false if the automatically added metric for the timestamp of the last failed push has a value larger than the value of the automatically added metric for the timestamp of the last successful push. In all other cases, it returns true (including the case that one or both of those metrics are missing for some reason.)

func (MetricGroup) SortedLabels

func (mg MetricGroup) SortedLabels() []string

SortedLabels returns the label names of the grouping labels sorted lexicographically but with the "job" label always first. This method exists for presentation purposes, see template.html.

type MetricStore

type MetricStore interface {
	// SubmitWriteRequest submits a WriteRequest for processing. There is no
	// guarantee when a request will be processed, but it is guaranteed that
	// the requests are processed in the order of submission.
	SubmitWriteRequest(req WriteRequest)
	// GetMetricFamilies returns all the currently saved MetricFamilies. The
	// returned MetricFamilies are guaranteed to not be modified by the
	// MetricStore anymore. However, they may still be read somewhere else,
	// so the caller is not allowed to modify the returned MetricFamilies.
	// If different groups have saved MetricFamilies of the same name, they
	// are all merged into one MetricFamily by concatenating the contained
	// Metrics. Inconsistent help strings are logged, and one of the
	// versions will "win". Inconsistent types and inconsistent or duplicate
	// label sets will go undetected.
	GetMetricFamilies() []*dto.MetricFamily
	// GetMetricFamiliesMap returns a map grouping-key -> MetricGroup. The
	// MetricFamily pointed to by the Metrics map in each MetricGroup is
	// guaranteed to not be modified by the MetricStore anymore. However,
	// they may still be read somewhere else, so the caller is not allowed
	// to modify it. Otherwise, the returned nested map can be seen as a
	// deep copy of the internal state of the MetricStore and completely
	// owned by the caller.
	GetMetricFamiliesMap() GroupingKeyToMetricGroup
	// Shutdown must only be called after the caller has made sure that
	// SubmitWriteRequests is not called anymore. (If it is called later,
	// the request might get submitted, but not processed anymore.) The
	// Shutdown method waits for the write request queue to empty, then it
	// persists the content of the MetricStore (if supported by the
	// implementation). Also, all internal goroutines are stopped. This
	// method blocks until all of that is complete. If an error is
	// encountered, it is returned (whereupon the MetricStorage is in an
	// undefinded state). If nil is returned, the MetricStore cannot be
	// "restarted" again, but it can still be used for read operations.
	Shutdown() error
	// Healthy returns nil if the MetricStore is currently working as
	// expected. Otherwise, a non-nil error is returned.
	Healthy() error
	// Ready returns nil if the MetricStore is ready to be used (all files
	// are opened and checkpoints have been restored). Otherwise, a non-nil
	// error is returned.
	Ready() error
}

MetricStore is the interface to the storage layer for metrics. All its methods must be safe to be called concurrently.

type NameToTimestampedMetricFamilyMap

type NameToTimestampedMetricFamilyMap map[string]TimestampedMetricFamily

NameToTimestampedMetricFamilyMap is the second level of the metric store, keyed by metric name.

type TimestampedMetricFamily

type TimestampedMetricFamily struct {
	Timestamp            time.Time
	GobbableMetricFamily *GobbableMetricFamily
}

TimestampedMetricFamily adds the push timestamp to a gobbable version of the MetricFamily-DTO.

func (TimestampedMetricFamily) GetMetricFamily

func (tmf TimestampedMetricFamily) GetMetricFamily() *dto.MetricFamily

GetMetricFamily returns the normal GetMetricFamily DTO (without the gob additions).

type WriteRequest

type WriteRequest struct {
	Labels         map[string]string
	Timestamp      time.Time
	MetricFamilies map[string]*dto.MetricFamily
	Replace        bool
	Done           chan error
}

WriteRequest is a request to change the MetricStore, i.e. to process it, a write lock has to be acquired.

If MetricFamilies is nil, this is a request to delete metrics that share the given Labels as a grouping key. Otherwise, this is a request to update the MetricStore with the MetricFamilies.

If Replace is true, the MetricFamilies will completely replace the metrics with the same grouping key. Otherwise, only those MetricFamilies with the same name as new MetricFamilies will be replaced.

The key in MetricFamilies is the name of the mapped metric family.

When the WriteRequest is processed, the metrics in MetricFamilies will be sanitized to have the same job and other labels as those in the Labels fields. Also, if there is no instance label, an instance label with an empty value will be set. This implies that the MetricFamilies in the WriteRequest may be modified be the MetricStore during processing of the WriteRequest!

The Timestamp field marks the time the request was received from the network. It is not related to the TimestampMs field in the Metric proto message. In fact, WriteRequests containing any Metrics with a TimestampMs set are invalid and will be rejected.

The Done channel may be nil. If it is not nil, it will be closed once the write request is processed. Any errors occurring during processing are sent to the channel before closing it.