Documentation
¶
Overview ¶
Package application manages individual applications for scotty.
Index ¶
Constants ¶
const ( // The name of the health agent application HealthAgentName = "health agent" // The port of the health agent application HealthAgentPort = 6910 )
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Application ¶
type Application struct {
// Used to collect metrics for this application. Each application has an
// unique value for this field that never changes.
EP *scotty.Endpoint
// The port that this application runs on. Unlike the EP field, the value
// of this field can change.
Port uint
// TODO: comment
IsTLS bool
// The statistics for collecting metrics from this application. This
// field changes.
EndpointStats
// True if this application is active. An application is active if
// health agent reports it. The value of this field can change.
Active bool
}
Application represents an application
type EndpointStats ¶
type EndpointStats struct {
// Time metrics were last read. Zero means never read.
LastReadTime time.Time
// Time spent during last poll.
PollTime time.Duration
LastError error
LastErrorTime time.Time
// Number of metrics read initially
InitialMetricCount uint64
// True if this application cannot be reached.
Down bool
// ChangedMetricsSum and ChangedMetricsCount are used to keep track of the
// average number of metrics that change.
ChangedMetricsSum uint64
ChangedMetricsCount uint64
// Status: e.g Synced, Polling, Connecting etc.
Status scotty.Status
}
Statistics for reading metrics for a particular application
func (*EndpointStats) AverageChangedMetrics ¶
func (e *EndpointStats) AverageChangedMetrics() float64
AverageChangedMetrics is a convenience routine that returns the average number of changing metrics.
func (*EndpointStats) LastErrorTimeStr ¶
func (e *EndpointStats) LastErrorTimeStr() string
LastErrorTimeStr is a convenience routine that reports last error time as a string formatted as 2006-01-02T15:04:05.
func (*EndpointStats) Staleness ¶
func (e *EndpointStats) Staleness() time.Duration
Staleness is a convenience routine that returns now minus the last read time. If metrics were never read, Staleness returns 0.
type Group ¶
type Group struct {
// contains filtered or unexported fields
}
Group contains applications running on a particular machine
func NewGroup ¶
NewGroup returns a new group instance. host identifies the machine; countToInactive is the number of times an application must be reported missing before it is marked inactive. Each new group always contains the health agent running on port 6910. In addition to the newly created instance, NewGroup returns the scotty.Endpoint for the health agent.
func (*Group) Applications ¶
func (g *Group) Applications() []*Application
Applications returns all the applications (both active and inactive) this instance has. Applications returns defensive copies of the Application objects.
func (*Group) ByName ¶
func (g *Group) ByName(name string) *Application
ByName returns an application by its name or nil if no such application exists. ByName returns a defensive copy of the Application object.
func (*Group) Modify ¶
func (g *Group) Modify(name string, mod func(*EndpointStats))
Modify modifies statistics for an application. name is the name of the application; mod modifies the statistics. Modify calls mod once to modify statistics in place.
func (*Group) SetApplications ¶
func (g *Group) SetApplications(namesAndPorts namesandports.NamesAndPorts) ( newApps, active, inactive []*scotty.Endpoint)
SetApplications tells this instance the names and ports of running applications. If a previously reported application isn't reported countToInactive times (see NewGroup) then SetApplications marks that application inactive. If an inactive application is listed in namesAndPorts, SetApplications marks it as active. namesandports need not include the health agent running on port 6910. That application is always active.
SetApplications returns the scotty.Endpoint for newly reported applications, previously inactive applications marked active, and previously active applications marked inactive.
Source Files