tmagent

Documentation

Index

• Constants
• type FailOver
• type Host
• type ParentAvailable
• type ParentInfo
  • func NewParentInfo(cfg config.Cfg) (*ParentInfo, error)
  • func (c *ParentInfo) GetCacheStatuses() (tc.CRStates, error)
  • func (c *ParentInfo) PollAndUpdateCacheStatus()
  • func (c *ParentInfo) UpdateParentInfo() error
  • func (c *ParentInfo) WritePollState() error
• type ParentStatus
  • func (p ParentStatus) Status() string
• type Protocol
• type StatusReason
  • func (s StatusReason) String() string
• type Strategies
• type Strategy

Constants

const (
	TrafficCtl     = "traffic_ctl"
	ParentsFile    = "parent.config"
	StrategiesFile = "strategies.yaml"
)

Types

type FailOver

type FailOver struct {
	MaxSimpleRetries      int      `yaml:"max_simple_retries,omitempty"`
	MaxUnavailableRetries int      `yaml:"max_unavailable_retries,omitempty"`
	RingMode              string   `yaml:"ring_mode,omitempty"`
	ResponseCodes         []int    `yaml:"response_codes,omitempty"`
	MarkDownCodes         []int    `yaml:"markdown_codes,omitempty"`
	HealthCheck           []string `yaml:"health_check,omitempty"`
}

when reading the 'strategies.yaml', these fields are used to help parse out fail_over objects.

type Host

type Host struct {
	HostName  string     `yaml:"host"`
	Protocols []Protocol `yaml:"protocol"`
}

the fields used from 'strategies.yaml' that describe a parent.

type ParentAvailable

type ParentAvailable interface {
	// contains filtered or unexported methods
}

type ParentInfo

type ParentInfo struct {
	ParentDotConfig        util.ConfigFile
	StrategiesDotYaml      util.ConfigFile
	TrafficServerBinDir    string
	TrafficServerConfigDir string
	Parents                map[string]ParentStatus
	Cfg                    config.Cfg
}

the necessary data required to keep track of trafficserver config files, lists of parents a trafficserver instance uses, and directory locations used for configuration and trafficserver executables.

func NewParentInfo

func NewParentInfo(cfg config.Cfg) (*ParentInfo, error)

used at startup to load a trafficservers list of parents from it's 'parent.config', 'strategies.yaml' and current parent status from trafficservers HostStatus subsystem.

func (*ParentInfo) GetCacheStatuses

func (c *ParentInfo) GetCacheStatuses() (tc.CRStates, error)

Queries a traffic monitor that is monitoring the trafficserver instance running on a host to obtain the availability, health, of a parent used by trafficserver.

func (*ParentInfo) PollAndUpdateCacheStatus

func (c *ParentInfo) PollAndUpdateCacheStatus()

The main polling function that keeps the parents list current if with any changes to the trafficserver 'parent.config' or 'strategies.yaml'. Also, it keeps parent status current with the the trafficserver HostStatus subsystem. Finally, on each poll cycle a trafficmonitor is queried to check that all parents used by this trafficserver are available for use based upon the trafficmonitors idea from it's health protocol. Parents are marked up or down in the trafficserver subsystem based upon that hosts current status and the status that trafficmonitor health protocol has determined for a parent.

func (*ParentInfo) UpdateParentInfo

func (c *ParentInfo) UpdateParentInfo() error

Used by the polling function to update the parents list from changes to 'parent.config' and 'strategies.yaml'. The parents availability is also updated to reflect the current state from the trafficserver HostStatus subsystem.

func (*ParentInfo) WritePollState

func (c *ParentInfo) WritePollState() error

type ParentStatus

type ParentStatus struct {
	Fqdn                 string
	ActiveReason         bool
	LocalReason          bool
	ManualReason         bool
	LastTmPoll           int64
	UnavailablePollCount int
	MarkUpPollCount      int
}

the trafficserver 'HostStatus' fields that are necessary to interface with the trafficserver 'traffic_ctl' command.

func (ParentStatus) Status

func (p ParentStatus) Status() string

used to log that a parent's status is either UP or DOWN based upon the HostStatus reason codes. to be considered UP, all reason codes must be 'true'.

type Protocol

type Protocol struct {
	Scheme           string  `yaml:"scheme"`
	Port             int     `yaml:"port"`
	Health_check_url string  `yaml:"health_check_url,omitempty"`
	Weight           float64 `yaml:"weight,omitempty"`
}

the protocol object in 'strategies.yaml' that help to describe a parent.

type StatusReason

type StatusReason int

const (
	ACTIVE StatusReason = iota
	LOCAL
	MANUAL
)

these are the HostStatus reason codes used withing trafficserver.

func (StatusReason) String

func (s StatusReason) String() string

used for logging a parent's HostStatus reason code setting.

type Strategies

type Strategies struct {
	Strategy []Strategy    `yaml:"strategies"`
	Hosts    []Host        `yaml:"hosts"`
	Groups   []interface{} `yaml:"groups"`
}

the top level array defintions in a trafficserver 'strategies.yaml' configuration file.

type Strategy

type Strategy struct {
	Strategy        string   `yaml:"strategy"`
	Policy          string   `yaml:"policy"`
	HashKey         string   `yaml:"hash_key,omitempty"`
	GoDirect        bool     `yaml:"go_direct,omitempty"`
	ParentIsProxy   bool     `yaml:"parent_is_proxy,omitempty"`
	CachePeerResult bool     `yaml:"cache_peer_result,omitempty"`
	Scheme          string   `yaml:"scheme"`
	FailOvers       FailOver `yaml:"failover,omitempty"`
}

a trafficserver strategy object from 'strategies.yaml'.