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Constants ¶
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Variables ¶
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Functions ¶
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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, ) *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.
func (*DiskMetricStore) GetMetricFamilies ¶
func (dms *DiskMetricStore) GetMetricFamilies() []*dto.MetricFamily
GetMetricFamilies implements the MetricStore interface.
func (*DiskMetricStore) GetMetricFamiliesMap ¶
func (dms *DiskMetricStore) GetMetricFamiliesMap() JobToInstanceMap
GetMetricFamiliesMap 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 InstanceToNameMap ¶
type InstanceToNameMap map[string]NameToTimestampedMetricFamilyMap
InstanceToNameMap is the second level of the metric store, keyed by instance name.
type JobToInstanceMap ¶
type JobToInstanceMap map[string]InstanceToNameMap
JobToInstanceMap is the first level of the metric store, keyed by job name.
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 jobs and instances have saved MetricFamilies of the same
// name, they are all merged into one MetricFamily by concatenating the
// contained Metrics. Inconsistent help strings or types are logged, and
// one of the versions will "win". Inconsistent labels will go
// undetected.
GetMetricFamilies() []*dto.MetricFamily
// GetMetricFamiliesMap returns a nested map (job -> instance ->
// metric-name -> TimestampedMetricFamily). The MetricFamily pointed to
// by each TimestampedMetricFamily 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 is a deep copy of the internal state of the
// MetricStore and completely owned by the caller.
GetMetricFamiliesMap() JobToInstanceMap
// 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
}
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 third level of the metric store, keyed by metric name.
type TimestampedMetricFamily ¶
type TimestampedMetricFamily struct {
Timestamp time.Time
MetricFamily *dto.MetricFamily
}
TimestampedMetricFamily adds a timestamp to a MetricFamily-DTO.
type WriteRequest ¶
type WriteRequest struct {
Job, Instance string
Timestamp time.Time
MetricFamilies map[string]*dto.MetricFamily
}
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 Job and (if not empty) Instance labels. Otherwise, this is a request to update the MetricStore with the MetricFamilies. The key in MetricFamilies is the name of the mapped metric family. All metrics in MetricFamilies MUST have already set job and instance labels that are consistent with the Job and Instance fields. The Timestamp field marks the time the request was received from the network. It is not related to the timestamp_ms field in the Metric proto message.
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