Documentation
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Overview ¶
Package control keeps track of resources and manages queries.
The Controller manages the resources available to each query by managing the memory allocation and concurrency usage of each query. The Controller will compile a program by using the passed in language and it will start the program using the ResourceManager.
It will guarantee that each program that is started has at least one goroutine that it can use with the dispatcher and it will ensure a minimum amount of memory is available before the program runs.
Other goroutines and memory usage is at the will of the specific resource strategy that the Controller is using.
The Controller also provides visibility into the lifetime of the query and its current resource usage.
Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func StartSpanFromContext ¶
func StartSpanFromContext(ctx context.Context, operationName string, hist prometheus.Observer, gauge prometheus.Gauge) (*span, context.Context)
Types ¶
type Config ¶
type Config struct {
// ConcurrencyQuota is the number of queries that are allowed to execute concurrently.
ConcurrencyQuota int
// MemoryBytesQuotaPerQuery is the maximum number of bytes (in table memory) a query is allowed to use at
// any given time.
//
// The maximum amount of memory the controller is allowed to consume is
// ConcurrencyQuota * MemoryBytesQuotaPerQuery
MemoryBytesQuotaPerQuery int64
// QueueSize is the number of queries that are allowed to be awaiting execution before new queries are
// rejected.
QueueSize int
Logger *zap.Logger
// MetricLabelKeys is a list of labels to add to the metrics produced by the controller.
// The value for a given key will be read off the context.
// The context value must be a string or an implementation of the Stringer interface.
MetricLabelKeys []string
ExecutorDependencies execute.Dependencies
}
type Controller ¶
type Controller struct {
// contains filtered or unexported fields
}
Controller provides a central location to manage all incoming queries. The controller is responsible for compiling, queueing, and executing queries.
func New ¶
func New(c Config) (*Controller, error)
func (*Controller) PrometheusCollectors ¶
func (c *Controller) PrometheusCollectors() []prometheus.Collector
PrometheusCollectors satisifies the prom.PrometheusCollector interface.
func (*Controller) Queries ¶
func (c *Controller) Queries() []*Query
Queries reports the active queries.
func (*Controller) Query ¶
Query submits a query for execution returning immediately. Done must be called on any returned Query objects.
func (*Controller) Shutdown ¶ added in v0.7.1
func (c *Controller) Shutdown(ctx context.Context) error
Shutdown will signal to the Controller that it should not accept any new queries and that it should finish executing any existing queries. This will return once the Controller's run loop has been exited and all queries have been finished or until the Context has been canceled.
type Query ¶
type Query struct {
// contains filtered or unexported fields
}
Query represents a single request.
func (*Query) Done ¶
func (q *Query) Done()
Done signals to the Controller that this query is no longer being used and resources related to the query may be freed.
func (*Query) Results ¶ added in v0.26.0
Results returns a channel that will deliver the query results.
It's possible that the channel is closed before any results arrive. In particular, if a query's context or the query itself is canceled, the query may close the results channel before any results are computed.
The query may also have an error during execution so the Err() function should be used to check if an error happened.
func (*Query) Statistics ¶
func (q *Query) Statistics() flux.Statistics
Statistics reports the statistics for the query.
This method must be called after Done. It will block until the query has been finalized unless a context is given.
type State ¶
type State int
State is the query state.
const ( // Created indicates the query has been created. Created State = iota // Compiling indicates that the query is in the process // of executing the compiler associated with the query. Compiling // Queueing indicates the query is waiting inside of the // scheduler to be executed. // TODO(jsternberg): This stage isn't used currently, but // it makes sense to readd this once we have a work queue again. Queueing // Executing indicates that the query is currently executing. Executing // Errored indicates that there was an error when attempting // to execute a query within any state inside of the controller. Errored // Finished indicates that the query has been marked as Done // and it is awaiting removal from the Controller or has already // been removed. Finished // Canceled indicates that the query was signaled to be // canceled. A canceled query must still be released with Done. Canceled )
Source Files
Directories
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| Path | Synopsis |
|---|---|
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Package controltest provides a controller for use in tests.
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Package controltest provides a controller for use in tests. |