promql

package
Version: v1.8.2 Latest Latest
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Published: Nov 4, 2017 License: Apache-2.0 Imports: 23 Imported by: 0

Documentation

Index

Constants

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const LowestPrec = 0 // Non-operators.

LowestPrec is a constant for operator precedence in expressions.

Variables

View Source
var DefaultEngineOptions = &EngineOptions{
	MaxConcurrentQueries: 20,
	Timeout:              2 * time.Minute,
}

DefaultEngineOptions are the default engine options.

View Source
var StalenessDelta = 5 * time.Minute

StalenessDelta determines the time since the last sample after which a time series is considered stale.

Functions

func Inspect

func Inspect(node Node, f func(Node) bool)

Inspect traverses an AST in depth-first order: It starts by calling f(node); node must not be nil. If f returns true, Inspect invokes f for all the non-nil children of node, recursively.

func ParseMetric

func ParseMetric(input string) (m model.Metric, err error)

ParseMetric parses the input into a metric

func ParseMetricSelector

func ParseMetricSelector(input string) (m metric.LabelMatchers, err error)

ParseMetricSelector parses the provided textual metric selector into a list of label matchers.

func Tree

func Tree(node Node) string

Tree returns a string of the tree structure of the given node.

func Walk

func Walk(v Visitor, node Node)

Walk traverses an AST in depth-first order: It starts by calling v.Visit(node); node must not be nil. If the visitor w returned by v.Visit(node) is not nil, Walk is invoked recursively with visitor w for each of the non-nil children of node, followed by a call of w.Visit(nil).

Types

type AggregateExpr

type AggregateExpr struct {
	Op               itemType         // The used aggregation operation.
	Expr             Expr             // The vector expression over which is aggregated.
	Param            Expr             // Parameter used by some aggregators.
	Grouping         model.LabelNames // The labels by which to group the vector.
	Without          bool             // Whether to drop the given labels rather than keep them.
	KeepCommonLabels bool             // Whether to keep common labels among result elements.
}

AggregateExpr represents an aggregation operation on a vector.

func (*AggregateExpr) String

func (node *AggregateExpr) String() string

func (*AggregateExpr) Type

func (e *AggregateExpr) Type() model.ValueType

type AlertStmt

type AlertStmt struct {
	Name        string
	Expr        Expr
	Duration    time.Duration
	Labels      model.LabelSet
	Annotations model.LabelSet
}

AlertStmt represents an added alert rule.

func (*AlertStmt) String

func (node *AlertStmt) String() string

type BinaryExpr

type BinaryExpr struct {
	Op       itemType // The operation of the expression.
	LHS, RHS Expr     // The operands on the respective sides of the operator.

	// The matching behavior for the operation if both operands are vectors.
	// If they are not this field is nil.
	VectorMatching *VectorMatching

	// If a comparison operator, return 0/1 rather than filtering.
	ReturnBool bool
}

BinaryExpr represents a binary expression between two child expressions.

func (*BinaryExpr) String

func (node *BinaryExpr) String() string

func (*BinaryExpr) Type

func (e *BinaryExpr) Type() model.ValueType

type Call

type Call struct {
	Func *Function   // The function that was called.
	Args Expressions // Arguments used in the call.
}

Call represents a function call.

func (*Call) String

func (node *Call) String() string

func (*Call) Type

func (e *Call) Type() model.ValueType

type Engine

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

Engine handles the lifetime of queries from beginning to end. It is connected to a querier.

func NewEngine

func NewEngine(queryable Queryable, o *EngineOptions) *Engine

NewEngine returns a new engine.

func (*Engine) NewInstantQuery

func (ng *Engine) NewInstantQuery(qs string, ts model.Time) (Query, error)

NewInstantQuery returns an evaluation query for the given expression at the given time.

func (*Engine) NewRangeQuery

func (ng *Engine) NewRangeQuery(qs string, start, end model.Time, interval time.Duration) (Query, error)

NewRangeQuery returns an evaluation query for the given time range and with the resolution set by the interval.

type EngineOptions

type EngineOptions struct {
	MaxConcurrentQueries int
	Timeout              time.Duration
}

EngineOptions contains configuration parameters for an Engine.

type ErrQueryCanceled

type ErrQueryCanceled string

ErrQueryCanceled is returned if a query was canceled during processing.

func (ErrQueryCanceled) Error

func (e ErrQueryCanceled) Error() string

type ErrQueryTimeout

type ErrQueryTimeout string

ErrQueryTimeout is returned if a query timed out during processing.

func (ErrQueryTimeout) Error

func (e ErrQueryTimeout) Error() string

type ErrStorage added in v1.6.0

type ErrStorage error

ErrStorage is returned if an error was encountered in the storage layer during query handling.

type EvalStmt

type EvalStmt struct {
	Expr Expr // Expression to be evaluated.

	// The time boundaries for the evaluation. If Start equals End an instant
	// is evaluated.
	Start, End model.Time
	// Time between two evaluated instants for the range [Start:End].
	Interval time.Duration
}

EvalStmt holds an expression and information on the range it should be evaluated on.

func (*EvalStmt) String

func (node *EvalStmt) String() string

type Expr

type Expr interface {
	Node

	// Type returns the type the expression evaluates to. It does not perform
	// in-depth checks as this is done at parsing-time.
	Type() model.ValueType
	// contains filtered or unexported methods
}

Expr is a generic interface for all expression types.

func ParseExpr

func ParseExpr(input string) (Expr, error)

ParseExpr returns the expression parsed from the input.

type Expressions

type Expressions []Expr

Expressions is a list of expression nodes that implements Node.

func (Expressions) String

func (es Expressions) String() (s string)

type Function

type Function struct {
	Name       string
	ArgTypes   []model.ValueType
	Variadic   int
	ReturnType model.ValueType
	Call       func(ev *evaluator, args Expressions) model.Value
}

Function represents a function of the expression language and is used by function nodes.

type MatrixSelector

type MatrixSelector struct {
	Name          string
	Range         time.Duration
	Offset        time.Duration
	LabelMatchers metric.LabelMatchers
	// contains filtered or unexported fields
}

MatrixSelector represents a matrix selection.

func (*MatrixSelector) String

func (node *MatrixSelector) String() string

func (*MatrixSelector) Type

func (e *MatrixSelector) Type() model.ValueType

type Node

type Node interface {
	// String representation of the node that returns the given node when parsed
	// as part of a valid query.
	String() string
}

Node is a generic interface for all nodes in an AST.

Whenever numerous nodes are listed such as in a switch-case statement or a chain of function definitions (e.g. String(), expr(), etc.) convention is to list them as follows:

- Statements
- statement types (alphabetical)
- ...
- Expressions
- expression types (alphabetical)
- ...

type NumberLiteral

type NumberLiteral struct {
	Val model.SampleValue
}

NumberLiteral represents a number.

func (*NumberLiteral) String

func (node *NumberLiteral) String() string

func (*NumberLiteral) Type

func (e *NumberLiteral) Type() model.ValueType

type ParenExpr

type ParenExpr struct {
	Expr Expr
}

ParenExpr wraps an expression so it cannot be disassembled as a consequence of operator precedence.

func (*ParenExpr) String

func (node *ParenExpr) String() string

func (*ParenExpr) Type

func (e *ParenExpr) Type() model.ValueType

type ParseErr

type ParseErr struct {
	Line, Pos int
	Err       error
}

ParseErr wraps a parsing error with line and position context. If the parsing input was a single line, line will be 0 and omitted from the error string.

func (*ParseErr) Error

func (e *ParseErr) Error() string

type Pos

type Pos int

Pos is the position in a string.

type Query

type Query interface {
	// Exec processes the query and
	Exec(ctx context.Context) *Result
	// Statement returns the parsed statement of the query.
	Statement() Statement
	// Stats returns statistics about the lifetime of the query.
	Stats() *stats.TimerGroup
	// Cancel signals that a running query execution should be aborted.
	Cancel()
}

A Query is derived from an a raw query string and can be run against an engine it is associated with.

type Queryable added in v1.3.0

type Queryable interface {
	Querier() (local.Querier, error)
}

Queryable allows opening a storage querier.

type RecordStmt

type RecordStmt struct {
	Name   string
	Expr   Expr
	Labels model.LabelSet
}

RecordStmt represents an added recording rule.

func (*RecordStmt) String

func (node *RecordStmt) String() string

type Result

type Result struct {
	Err   error
	Value model.Value
}

Result holds the resulting value of an execution or an error if any occurred.

func (*Result) Matrix

func (r *Result) Matrix() (model.Matrix, error)

Matrix returns a matrix. An error is returned if the result was an error or the result value is not a matrix.

func (*Result) Scalar

func (r *Result) Scalar() (*model.Scalar, error)

Scalar returns a scalar value. An error is returned if the result was an error or the result value is not a scalar.

func (*Result) String

func (r *Result) String() string

func (*Result) Vector

func (r *Result) Vector() (model.Vector, error)

Vector returns a vector if the result value is one. An error is returned if the result was an error or the result value is not a vector.

type Statement

type Statement interface {
	Node
	// contains filtered or unexported methods
}

Statement is a generic interface for all statements.

type Statements

type Statements []Statement

Statements is a list of statement nodes that implements Node.

func ParseStmts

func ParseStmts(input string) (Statements, error)

ParseStmts parses the input and returns the resulting statements or any occurring error.

func (Statements) String

func (stmts Statements) String() (s string)

type StringLiteral

type StringLiteral struct {
	Val string
}

StringLiteral represents a string.

func (*StringLiteral) String

func (node *StringLiteral) String() string

func (*StringLiteral) Type

func (e *StringLiteral) Type() model.ValueType

type Test

type Test struct {
	testutil.T
	// contains filtered or unexported fields
}

Test is a sequence of read and write commands that are run against a test storage.

func NewTest

func NewTest(t testutil.T, input string) (*Test, error)

NewTest returns an initialized empty Test.

func (*Test) Close

func (t *Test) Close()

Close closes resources associated with the Test.

func (*Test) Context added in v1.2.0

func (t *Test) Context() context.Context

Context returns the test's context.

func (*Test) QueryEngine

func (t *Test) QueryEngine() *Engine

QueryEngine returns the test's query engine.

func (*Test) Run

func (t *Test) Run() error

Run executes the command sequence of the test. Until the maximum error number is reached, evaluation errors do not terminate execution.

func (*Test) Storage

func (t *Test) Storage() local.Storage

Storage returns the test's storage.

type UnaryExpr

type UnaryExpr struct {
	Op   itemType
	Expr Expr
}

UnaryExpr represents a unary operation on another expression. Currently unary operations are only supported for scalars.

func (*UnaryExpr) String

func (node *UnaryExpr) String() string

func (*UnaryExpr) Type

func (e *UnaryExpr) Type() model.ValueType

type VectorMatchCardinality

type VectorMatchCardinality int

VectorMatchCardinality describes the cardinality relationship of two vectors in a binary operation.

const (
	CardOneToOne VectorMatchCardinality = iota
	CardManyToOne
	CardOneToMany
	CardManyToMany
)

func (VectorMatchCardinality) String

func (vmc VectorMatchCardinality) String() string

type VectorMatching

type VectorMatching struct {
	// The cardinality of the two vectors.
	Card VectorMatchCardinality
	// MatchingLabels contains the labels which define equality of a pair of
	// elements from the vectors.
	MatchingLabels model.LabelNames
	// On includes the given label names from matching,
	// rather than excluding them.
	On bool
	// Include contains additional labels that should be included in
	// the result from the side with the lower cardinality.
	Include model.LabelNames
}

VectorMatching describes how elements from two vectors in a binary operation are supposed to be matched.

type VectorSelector

type VectorSelector struct {
	Name          string
	Offset        time.Duration
	LabelMatchers metric.LabelMatchers
	// contains filtered or unexported fields
}

VectorSelector represents a vector selection.

func (*VectorSelector) String

func (node *VectorSelector) String() string

func (*VectorSelector) Type

func (e *VectorSelector) Type() model.ValueType

type Visitor

type Visitor interface {
	Visit(node Node) (w Visitor)
}

Visitor allows visiting a Node and its child nodes. The Visit method is invoked for each node encountered by Walk. If the result visitor w is not nil, Walk visits each of the children of node with the visitor w, followed by a call of w.Visit(nil).

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