config

Documentation

Overview

Package config contains the configuration for a Akutan server. The configuration is typically loaded from a JSON file on disk.

Index

• func Write(cfg *Akutan, filename string) error
• type API
• type Akutan
  • func Load(filename string) (*Akutan, error)
• type AkutanLog
• type DiskView
• type Locator
• type Tracing
• type TxTimeoutView

Functions

func Write

func Write(cfg *Akutan, filename string) error

Write marshalls the configuration as JSON to the given file. It truncates the file if it already exists. It returns nil upon success. Otherwise, it returns an error, which already includes the filename.

Types

type API

type API struct {
	// The host:port or :port on which to serve GRPC requests. Required.
	GRPCAddress string `json:"grpcAddress"`

	// The host:port or :port on which to serve HTTP requests (admin, metrics,
	// etc). Required.
	HTTPAddress string `json:"httpAddress"`

	// Experimental: if true, queries will collect significant information and
	// dump them on disk somewhere. If false (or unset), it won't.
	DebugQuery bool `json:"debugQuery"`
}

API contains configuration specific to the API servers.

type Akutan

type Akutan struct {
	// How to access the database change request log. Required on all
	// servers.
	AkutanLog AkutanLog `json:"akutanLog"`

	// Where to find the GRPC ports of all the view instances. Required on all
	// servers.
	ViewsLocator Locator `json:"viewsLocator"`

	// If non-nil, the configuration for distributed tracing (OpenTracing). If
	// nil, the server will not collect traces.
	Tracing *Tracing `json:"tracing,omitempty"`

	// Configuration for API servers. Ignored for other types of servers.
	API *API `json:"api,omitempty"`

	// Configuration for transaction timeout view servers. Ignored for other
	// types of servers.
	TxTimeoutView *TxTimeoutView `json:"txTimeoutView,omitempty"`

	// Configuration for disk view servers. Ignored for other types of servers.
	DiskView *DiskView `json:"diskView,omitempty"`
}

Akutan describes the configuration for a Akutan server.

func Load

func Load(filename string) (*Akutan, error)

Load parses the configuration from the given JSON file. Upon success, it returns a non-nil configuration. Otherwise, it returns an error, which already includes the filename.

type AkutanLog

type AkutanLog struct {
	// Either "logspec" for the logspec store, or "kafka"
	Type string `json:"type"`

	// For the logspec store, the GRPC endpoints on the servers. For Kafka, the
	// broker ports.
	Locator Locator `json:"locator"`
}

AkutanLog contains configuration describing how to access the Akutan database change request log.

type DiskView

type DiskView struct {
	// The host:port or :port on which to serve GRPC requests. Required.
	GRPCAddress string `json:"grpcAddress"`

	// If non-empty, the host:port or :port on which to serve Prometheus metrics
	// over HTTP. If empty (or unset), the metrics will not be served.
	MetricsAddress string `json:"metricsAddress"`

	// Either "hashsp" or "hashpo". Required.
	//
	// "hashsp" and "hashpo" are two critically important hash-spaces for Akutan;
	// each covers the entire set of facts stored. Facts in the "hashsp" space
	// are distributed by the hash of the fact's subject and predicate. Facts in
	// the "hashpo" space are distributed by the hash of the fact's predicate
	// and object.
	Space string `json:"space"`

	// The server will store all facts that hash from FirstHash up through and
	// including LastHash in the corresponding Space. Both are required, and
	// LastHash must be at least as large as FirstHash. The "hashsp" and
	// "hashpo" spaces range from "0x0000000000000000" through
	// "0xffffffffffffffff", inclusive. The format must match "0x%016x" exactly.
	FirstHash string `json:"firstHash"`
	LastHash  string `json:"lastHash"`

	// Must be "rocksdb", which indicates the server will store facts in
	// RocksDB. Required.
	Backend string `json:"backend"`

	// Used to decide when to replay the log vs request a carousel at startup.
	// If > 0, indicates how many log entries the server is behind before using
	// a carousel to catchup rather than reading the log. If 0 (or unset), the
	// server will only use the carousel when the log has already discarded the
	// next entry needed for log replay. Values < 0 are undefined.
	CarouselCatchupLag int64 `json:"carouselCatchupLag"`

	// If true, disables the behavior where multiple clients can read the entire
	// disk contents at once; carousel requests will instead do simple disk
	// iterations. If false (or unset), the more efficient but more complex
	// implementation is enabled.
	DisableCarousel bool `json:"disableCarousel"`

	// If "snappy" or "lz4", the server will store all data on disk using that
	// compression algorithm. If "none" or the empty string (or unset), the
	// server will store its data without compression.
	Compression string `json:"compression"`

	// If true, enables the ability to wipe the disk view removing the entire
	// data set. If false (or unset), such requests are ignored. This should
	// generally be disabled (false) on production clusters.
	EnableWipe bool `json:"enableWipe"`

	// The base location of the database file(s) for this server. Required.
	Dir string `json:"dir"`
}

DiskView contains configuration specific to DiskView servers.

type Locator

type Locator struct {
	// Either "static" or "kube".
	Type string `json:"type"`

	// Required for static locators; ignored otherwise. The host:port endpoints
	// that the locator will return. These are assumed to be TCP ports.
	Addresses []string `json:"addresses,omitempty"`

	// Required for Kubernetes locators; ignored otherwise. A Kubernetes label
	// selector to filter pods in the current namespace. See
	// https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/#label-selectors.
	LabelSelector string `json:"labelSelector,omitempty"`
	// Required for Kubernetes locators; ignored otherwise. Within the selected
	// pods, ports with this name on any container will be returned as endpoints.
	PortName string `json:"portName,omitempty"`
}

A Locator specifies how to find endpoints to communicate with. For this purpose, an endpoint is a particular port on a server or service.

type Tracing

type Tracing struct {
	// Must be "jaeger" (for now).
	Type string `json:"type"`

	// Endpoints that accept jaeger.thrift over HTTP directly from clients.
	Locator Locator `json:"locator"`
}

Tracing contains configuration related to distributed execution tracing.

type TxTimeoutView

type TxTimeoutView struct {
	// The host:port or :port on which to serve GRPC requests. Required.
	GRPCAddress string `json:"grpcAddress"`

	// If non-empty, the host:port or :port on which to serve Prometheus metrics
	// over HTTP. If empty (or unset), the metrics will not be served.
	MetricsAddress string `json:"metricsAddress"`
}

TxTimeoutView contains configuration specific to transaction timer servers.