Documentation
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Overview ¶
Package quota defines Trillian's Quota Management service.
The objective of the quota service is to protect Trillian from traffic peaks, rejecting requests that may put servers out of capacity or indirectly cause MMDs (maximum merge delays) to be missed.
Each Trillian request, be it either a read or write request, requires certain tokens to be allowed to continue. Tokens exist at multiple layers: per-user, per-tree and global tokens. For example, a TrillianLog.QueueLeaves request consumes a Write token from User, Tree and Global quotas. If any of those quotas is out of tokens, the request is denied with a ResourceExhausted error code.
Tokens are replenished according to each implementation. For example, User tokens may replenish over time, whereas {Write, Tree} tokens may replenish as sequencing happens. Implementations are free to ignore (effectively whitelisting) certain specs of tokens (e.g., only support Global and ignore User and Tree tokens).
Quota users are defined according to each implementation. Note that quota users don't need to match authentication/authorization users; implementations are allowed their own representation of users.
Index ¶
- Constants
- type Group
- type Kind
- type Manager
- type MockManager
- func (_m *MockManager) EXPECT() *_MockManagerRecorder
- func (_m *MockManager) GetTokens(_param0 context.Context, _param1 int, _param2 []Spec) error
- func (_m *MockManager) GetUser(_param0 context.Context, _param1 interface{}) string
- func (_m *MockManager) PeekTokens(_param0 context.Context, _param1 []Spec) (map[Spec]int, error)
- func (_m *MockManager) PutTokens(_param0 context.Context, _param1 int, _param2 []Spec) error
- func (_m *MockManager) ResetQuota(_param0 context.Context, _param1 []Spec) error
- type Spec
Constants ¶
const MaxTokens = int(^uint(0) >> 1) // MaxInt
MaxTokens is the maximum number of available tokens a quota may have.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Group ¶
type Group int
Group represents the scope of a token (Global, Tree or User).
const ( // Global is the Trillian-wide token scope (applies to all users and trees). // A global quota shortage for a certain kind of token means all requests of that kind will // be denied until the quota is replenished. Global Group = iota // Tree is the tree-wide token scope. Tree // User it the per-user token scope. // Users are defined according to each implementation. User )
type Manager ¶
type Manager interface {
// GetUser returns the quota user, as defined by the manager implementation.
// req is the RPC request message.
GetUser(ctx context.Context, req interface{}) string
// GetTokens acquires numTokens from all specs. Tokens are taken in the order specified by
// specs.
// Returns error if numTokens could not be acquired for all specs.
GetTokens(ctx context.Context, numTokens int, specs []Spec) error
// PeekTokens returns how many tokens are available for each spec, without acquiring any.
// Infinite quotas should return MaxTokens.
PeekTokens(ctx context.Context, specs []Spec) (map[Spec]int, error)
// PutTokens adds numTokens for all specs.
PutTokens(ctx context.Context, numTokens int, specs []Spec) error
// ResetQuota resets the quota for all specs.
ResetQuota(ctx context.Context, specs []Spec) error
}
Manager is the component responsible for the management of tokens.
type MockManager ¶
type MockManager struct {
// contains filtered or unexported fields
}
Mock of Manager interface
func NewMockManager ¶
func NewMockManager(ctrl *gomock.Controller) *MockManager
func (*MockManager) EXPECT ¶
func (_m *MockManager) EXPECT() *_MockManagerRecorder
func (*MockManager) GetUser ¶
func (_m *MockManager) GetUser(_param0 context.Context, _param1 interface{}) string
func (*MockManager) PeekTokens ¶
func (*MockManager) ResetQuota ¶
func (_m *MockManager) ResetQuota(_param0 context.Context, _param1 []Spec) error
type Spec ¶
type Spec struct {
// Group of the spec.
Group
// Kind of the spec.
Kind
// TreeID identifies the tree for specs of the Tree group.
// Not used for other specs.
TreeID int64
// User identifies the user for specs of the User group.
// Not used for other specs.
User string
}
Spec represents a combination of Group and Kind, with all additional data required to get / put tokens.
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