ha

Documentation

Overview

Package ha implements a high availability clustering mode for the agent. It is also referred to as the "scraping service" mode, as this is a fairly accurate description of what it does: a series of configs are stored in a KV store and a cluster of agents pulls configs from the store and shards them amongst the cluster, thereby distributing scraping load.

Index

• func GetCodec() codec.Codec
• type APIHandler
• type Config
  • func (c *Config) RegisterFlags(f *flag.FlagSet)
  • func (c *Config) RegisterFlagsWithPrefix(prefix string, f *flag.FlagSet)
• type ConfigManager
• type ReadRing
• type Server
  • func New(cfg Config, globalConfig *config.GlobalConfig, clientConfig client.Config, ...) (*Server, error)
  • func (s *Server) AllConfigs(ctx context.Context) (<-chan instance.Config, error)
  • func (s *Server) DeleteConfiguration(r *http.Request) (interface{}, error)
  • func (s *Server) Flush()
  • func (s *Server) GetConfiguration(r *http.Request) (interface{}, error)
  • func (s *Server) ListConfigurations(r *http.Request) (interface{}, error)
  • func (s *Server) PutConfiguration(r *http.Request) (interface{}, error)
  • func (s *Server) Reshard(ctx context.Context, _ *agentproto.ReshardRequest) (_ *empty.Empty, err error)
  • func (s *Server) Stop() error
  • func (s *Server) TransferOut(ctx context.Context) error
  • func (s *Server) WireAPI(r *mux.Router)
  • func (s *Server) WireGRPC(srv *grpc.Server)
  • func (s *Server) WrapHandler(next APIHandler) http.HandlerFunc
• type ShardingConfigManager
  • func NewShardingConfigManager(logger log.Logger, wrap ConfigManager, ring ReadRing, addr string) ShardingConfigManager
  • func (m ShardingConfigManager) ApplyConfig(c instance.Config)
  • func (m ShardingConfigManager) DeleteConfig(name string) error
  • func (m ShardingConfigManager) ListConfigs() map[string]instance.Config

Functions

func GetCodec

func GetCodec() codec.Codec

GetCodec returns the codec for encoding and decoding instance.Configs

Types

type APIHandler

type APIHandler func(r *http.Request) (interface{}, error)

APIHandler is a function that returns a configapi Response type and optionally an error.

type Config

type Config struct {
	Enabled         bool                  `yaml:"enabled"`
	ReshardInterval time.Duration         `yaml:"reshard_interval"`
	KVStore         kv.Config             `yaml:"kvstore"`
	Lifecycler      ring.LifecyclerConfig `yaml:"lifecycler"`
}

Config describes how to instantiate a scraping service Server instance.

func (*Config) RegisterFlags

func (c *Config) RegisterFlags(f *flag.FlagSet)

RegisterFlags adds the flags required to config the Server to the given FlagSet.

func (*Config) RegisterFlagsWithPrefix

func (c *Config) RegisterFlagsWithPrefix(prefix string, f *flag.FlagSet)

RegisterFlagsWithPrefix adds the flags required to config this to the given FlagSet with a specified prefix.

type ConfigManager

type ConfigManager interface {
	// ListConfigs gets the list of currently known configs.
	ListConfigs() map[string]instance.Config

	// ApplyConfig adds or updates a config.
	ApplyConfig(c instance.Config)

	// DeleteConfig deletes a config by name, uniquely keyed by the
	// Name field in instance.Config.
	DeleteConfig(name string) error
}

ConfigManager is an interface to manipulating a set of running instance.Configs. It is satisfied by the ConfigManager struct in pkg/prom, but is provided as an interface here for testing and avoiding import cycles.

type ReadRing

type ReadRing interface {
	http.Handler

	Get(key uint32, op ring.Operation, buf []ring.IngesterDesc) (ring.ReplicationSet, error)
	GetAll() (ring.ReplicationSet, error)
}

ReadRing is a subset of the Cortex ring.ReadRing interface with only the functionality used by the HA server.

type Server

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

Server implements the HA scraping service.

func New

func New(cfg Config, globalConfig *config.GlobalConfig, clientConfig client.Config, logger log.Logger, cm ConfigManager) (*Server, error)

New creates a new HA scraping service instance.

func (*Server) AllConfigs

func (s *Server) AllConfigs(ctx context.Context) (<-chan instance.Config, error)

AllConfigs gets all configs known to the KV store.

func (*Server) DeleteConfiguration

func (s *Server) DeleteConfiguration(r *http.Request) (interface{}, error)

DeleteConfiguration deletes an existing named configuration.

func (*Server) Flush

func (s *Server) Flush()

Flush satisfies ring.FlushTransferer. It is a no-op for the Agent.

func (*Server) GetConfiguration

func (s *Server) GetConfiguration(r *http.Request) (interface{}, error)

GetConfiguration returns an existing named configuration.

func (*Server) ListConfigurations

func (s *Server) ListConfigurations(r *http.Request) (interface{}, error)

ListConfigurations returns a list of the named configurations or all configurations associated with the Prometheus agent.

func (*Server) PutConfiguration

func (s *Server) PutConfiguration(r *http.Request) (interface{}, error)

PutConfiguration creates or updates a named configuration. Completely overrides the previous configuration if it exists.

func (*Server) Reshard

func (s *Server) Reshard(ctx context.Context, _ *agentproto.ReshardRequest) (_ *empty.Empty, err error)

Reshard initiates an entire reshard of the current HA scraping service instance. All configs will be reloaded from the KV store and the scraping service instance will see what should be managed locally.

Satisfies agentproto.ScrapingServiceServer.

func (*Server) Stop

func (s *Server) Stop() error

Stop stops the HA server and its dependencies.

func (*Server) TransferOut

func (s *Server) TransferOut(ctx context.Context) error

TransferOut satisfies ring.FlushTransferer. It connects to all other healthy agents in the cluster and tells them to reshard.

func (*Server) WireAPI

func (s *Server) WireAPI(r *mux.Router)

WireAPI injects routes into the provided mux router for the config management API.

func (*Server) WireGRPC

func (s *Server) WireGRPC(srv *grpc.Server)

WireGRPC injects gRPC server handlers into the provided gRPC server.

func (*Server) WrapHandler

func (s *Server) WrapHandler(next APIHandler) http.HandlerFunc

WrapHandler is responsible for turning an APIHandler into an HTTP handler by wrapping responses and writing them as JSON.

type ShardingConfigManager

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

ShardingConfigManager wraps around an existing ConfigManager and uses a hash ring to determine if a config should be applied. If an applied config used to be owned by the local address but no longer does, it will be deleted on the next apply.

func NewShardingConfigManager

func NewShardingConfigManager(logger log.Logger, wrap ConfigManager, ring ReadRing, addr string) ShardingConfigManager

NewShardingConfigManager creates a new ShardingConfigManager. The wrap argument holds the underlying config manager, while ring and addr are used together to do hash ring lookups: for a given hash, a config is owned by the ShardingConfigManager if the address of a node from a lookup matches the addr argument passed to NewShardingConfigManager.

func (ShardingConfigManager) ApplyConfig

func (m ShardingConfigManager) ApplyConfig(c instance.Config)

ApplyConfig implements ConfigManager.ApplyConfig.

func (ShardingConfigManager) DeleteConfig

func (m ShardingConfigManager) DeleteConfig(name string) error

DeleteConfig implements ConfigManager.DeleteConfig.

func (ShardingConfigManager) ListConfigs

func (m ShardingConfigManager) ListConfigs() map[string]instance.Config

ListConfigs implements ConfigManager.ListConfigs.