promql

package
v0.0.0-...-bfdd474 Latest Latest
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 Go to latest Published: Aug 28, 2015 License: Apache-2.0 Imports: 21 Imported by: 0

Documentation

Index

Constants

View Source 
const LowestPrec = 0 // Non-operators.

Constants 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.
	Grouping        model.LabelNames // The labels by which to group the vector.
	KeepExtraLabels bool             // Whether to keep extra labels common 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
	Summary     string
	Description string
	Runbook     string
}

AlertStmt represents an added alert rule.

func (*AlertStmt) String 

func (node *AlertStmt) String() string

type Analyzer 

type Analyzer struct {
	// The storage from which to query data.
	Storage local.Storage
	// The expression being analyzed.
	Expr Expr
	// The time range for evaluation of Expr.
	Start, End model.Time
	// contains filtered or unexported fields
}

An Analyzer traverses an expression and determines which data has to be requested from the storage. It is bound to a context that allows cancellation and timing out.

func (*Analyzer) Analyze 

func (a *Analyzer) Analyze(ctx context.Context) error

Analyze the provided expression and attach metrics and fingerprints to data-selecting AST nodes that are later used to preload the data from the storage.

func (*Analyzer) Prepare 

func (a *Analyzer) Prepare(ctx context.Context) (local.Preloader, error)

Prepare the expression evaluation by preloading all required chunks from the storage and setting the respective storage iterators in the AST nodes.

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
}

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 storage.

func NewEngine 

func NewEngine(storage local.Storage, 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.

func (*Engine) Stop 

func (ng *Engine) Stop()

Stop the engine and cancel all running queries.

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 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
	OptionalArgs 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 precendence.

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() *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 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 ocurring 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) 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
	// On contains the labels which define equality of a pair
	// of elements from the vectors.
	On model.LabelNames
	// Include contains additional labels that should be included in
	// the result from the side with the higher 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).

Source Files

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