crdb

README

CockroachDB Datastore

CockroachDB is a Spanner-like datastore supporting global, immediate consistency, with the mantra "no stale reads." The CockroachDB implementation should be used when your SpiceDB service runs in multiple geographic regions, and Google's Cloud Spanner is unavailable (e.g. AWS, Azure, bare metal.)

Implementation Caveats

In order to prevent the new-enemy problem, we need to make related transactions overlap. We do this by choosing a common database key and writing to that key with all relationships that may overlap. This tradeoff is cataloged in our blog post The One Crucial Difference Between Spanner and CockroachDB.

Documentation

Index

• Constants
• func NewCRDBDatastore(url string, options ...Option) (datastore.Datastore, error)
• type Option
  • func ConnHealthCheckInterval(interval time.Duration) Option
  • func ConnMaxIdleTime(idle time.Duration) Option
  • func ConnMaxLifetime(lifetime time.Duration) Option
  • func DisableStats(disable bool) Option
  • func FollowerReadDelay(delay time.Duration) Option
  • func GCWindow(window time.Duration) Option
  • func MaxOpenConns(conns int) Option
  • func MaxRetries(maxRetries uint8) Option
  • func MaxRevisionStalenessPercent(stalenessPercent float64) Option
  • func MinOpenConns(conns int) Option
  • func OverlapKey(key string) Option
  • func OverlapStrategy(strategy string) Option
  • func RevisionQuantization(bucketSize time.Duration) Option
  • func SplitAtUsersetCount(splitAtUsersetCount uint16) Option
  • func WatchBufferLength(watchBufferLength uint16) Option
  • func WithEnablePrometheusStats(enablePrometheusStats bool) Option

Constants

const (
	Engine = "cockroachdb"
)

Functions

func NewCRDBDatastore

func NewCRDBDatastore(url string, options ...Option) (datastore.Datastore, error)

NewCRDBDatastore initializes a SpiceDB datastore that uses a CockroachDB database while leveraging its AOST functionality.

Types

type Option

type Option func(*crdbOptions)

Option provides the facility to configure how clients within the CRDB datastore interact with the running CockroachDB database.

func ConnHealthCheckInterval

func ConnHealthCheckInterval(interval time.Duration) Option

ConnHealthCheckInterval is the frequency at which both idle and max lifetime connections are checked, and also the frequency at which the minimum number of connections is checked. This happens asynchronously.

This is not the only approach to evaluate these counts: connection idle/max lifetime is also checked when connections are released to the pool.

There is no guarantee connections won't last longer than their specified idle/max lifetime. It's largely dependent on the health-check goroutine being able to pull them from the connection pool. The health-check may not be able to clean up those connections if they are held by the application very frequently.

This value defaults to 30s.

func ConnMaxIdleTime

func ConnMaxIdleTime(idle time.Duration) Option

ConnMaxIdleTime is the duration after which an idle connection will be automatically closed by the health check.

This value defaults to having no maximum.

func ConnMaxLifetime

func ConnMaxLifetime(lifetime time.Duration) Option

ConnMaxLifetime is the duration since creation after which a connection will be automatically closed.

This value defaults to having no maximum.

func DisableStats

func DisableStats(disable bool) Option

DisableStats disables recording counts to the stats table

func FollowerReadDelay

func FollowerReadDelay(delay time.Duration) Option

FollowerReadDelay is the time delay to apply to enable historial reads.

This value defaults to 0 seconds.

func GCWindow

func GCWindow(window time.Duration) Option

GCWindow is the maximum age of a passed revision that will be considered valid.

This value defaults to 24 hours.

func MaxOpenConns

func MaxOpenConns(conns int) Option

MaxOpenConns is the maximum size of the connection pool.

This value defaults to having no maximum.

func MaxRetries

func MaxRetries(maxRetries uint8) Option

MaxRetries is the maximum number of times a retriable transaction will be client-side retried. Default: 5

func MaxRevisionStalenessPercent

func MaxRevisionStalenessPercent(stalenessPercent float64) Option

MaxRevisionStalenessPercent is the amount of time, expressed as a percentage of the revision quantization window, that a previously computed rounded revision can still be advertised after the next rounded revision would otherwise be ready.

This value defaults to 0.1 (10%).

func MinOpenConns

func MinOpenConns(conns int) Option

MinOpenConns is the minimum size of the connection pool. The health check will increase the number of connections to this amount if it had dropped below.

This value defaults to zero.

func OverlapKey

func OverlapKey(key string) Option

OverlapKey is a key touched on every write if OverlapStrategy is "static" Default: 'key'

func OverlapStrategy

func OverlapStrategy(strategy string) Option

OverlapStrategy is the strategy used to generate overlap keys on write. Default: 'static'

func RevisionQuantization

func RevisionQuantization(bucketSize time.Duration) Option

RevisionQuantization is the time bucket size to which advertised revisions will be rounded.

This value defaults to 5 seconds.

func SplitAtUsersetCount

func SplitAtUsersetCount(splitAtUsersetCount uint16) Option

SplitAtUsersetCount is the batch size for which userset queries will be split into smaller queries.

This defaults to 1024.

func WatchBufferLength

func WatchBufferLength(watchBufferLength uint16) Option

WatchBufferLength is the number of entries that can be stored in the watch buffer while awaiting read by the client.

This value defaults to 128.

func WithEnablePrometheusStats

func WithEnablePrometheusStats(enablePrometheusStats bool) Option

WithEnablePrometheusStats marks whether Prometheus metrics provided by the Postgres clients being used by the datastore are enabled.

Prometheus metrics are disabled by default.