cadence: go.uber.org/cadence/worker Index | Files

package worker

import "go.uber.org/cadence/worker"

Package worker contains functions to manage lifecycle of a Cadence client side worker.

Index

Package Files

worker.go

Constants

const (
    // NonDeterministicWorkflowPolicyBlockWorkflow is the default policy for handling detected non-determinism.
    // This option simply logs to console with an error message that non-determinism is detected, but
    // does *NOT* reply anything back to the server.
    // It is chosen as default for backward compatibility reasons because it preserves the old behavior
    // for handling non-determinism that we had before NonDeterministicWorkflowPolicy type was added to
    // allow more configurability.
    NonDeterministicWorkflowPolicyBlockWorkflow = internal.NonDeterministicWorkflowPolicyBlockWorkflow
    // NonDeterministicWorkflowPolicyFailWorkflow behaves exactly the same as Ignore, up until the very
    // end of processing a decision task.
    // Whereas default does *NOT* reply anything back to the server, fail workflow replies back with a request
    // to fail the workflow execution.
    NonDeterministicWorkflowPolicyFailWorkflow = internal.NonDeterministicWorkflowPolicyFailWorkflow
)

func EnableVerboseLogging Uses

func EnableVerboseLogging(enable bool)

EnableVerboseLogging enable or disable verbose logging of internal Cadence library components. Most customers don't need this feature, unless advised by the Cadence team member. Also there is no guarantee that this API is not going to change.

func ReplayPartialWorkflowHistoryFromJSONFile Uses

func ReplayPartialWorkflowHistoryFromJSONFile(logger *zap.Logger, jsonfileName string, lastEventID int64) error

ReplayPartialWorkflowHistoryFromJSONFile executes a single decision task for the json history file upto provided // lastEventID(inclusive), downloaded from the cli. To download the history file: cadence workflow showid <workflow_id> -of <output_filename> See https://github.com/uber/cadence/blob/master/tools/cli/README.md for full documentation Use for testing the backwards compatibility of code changes and troubleshooting workflows in a debugger. The logger is an optional parameter. Defaults to the noop logger.

func ReplayWorkflowExecution Uses

func ReplayWorkflowExecution(ctx context.Context, service workflowserviceclient.Interface, logger *zap.Logger, domain string, execution workflow.Execution) error

ReplayWorkflowExecution loads a workflow execution history from the Cadence service and executes a single decision task for it. Use for testing the backwards compatibility of code changes and troubleshooting workflows in a debugger. The logger is the only optional parameter. Defaults to the noop logger.

func ReplayWorkflowHistory Uses

func ReplayWorkflowHistory(logger *zap.Logger, history *shared.History) error

ReplayWorkflowHistory executes a single decision task for the given json history file. Use for testing the backwards compatibility of code changes and troubleshooting workflows in a debugger. The logger is an optional parameter. Defaults to the noop logger.

func ReplayWorkflowHistoryFromJSONFile Uses

func ReplayWorkflowHistoryFromJSONFile(logger *zap.Logger, jsonfileName string) error

ReplayWorkflowHistoryFromJSONFile executes a single decision task for the json history file downloaded from the cli. To download the history file: cadence workflow showid <workflow_id> -of <output_filename> See https://github.com/uber/cadence/blob/master/tools/cli/README.md for full documentation Use for testing the backwards compatibility of code changes and troubleshooting workflows in a debugger. The logger is an optional parameter. Defaults to the noop logger.

func SetBinaryChecksum Uses

func SetBinaryChecksum(checksum string)

SetBinaryChecksum sets the identifier of the binary(aka BinaryChecksum). The identifier is mainly used in recording reset points when respondDecisionTaskCompleted. For each workflow, the very first decision completed by a binary will be associated as a auto-reset point for the binary. So that when a customer wants to mark the binary as bad, the workflow will be reset to that point -- which means workflow will forget all progress generated by the binary. On another hand, once the binary is marked as bad, the bad binary cannot poll decision and make any progress any more.

func SetStickyWorkflowCacheSize Uses

func SetStickyWorkflowCacheSize(cacheSize int)

SetStickyWorkflowCacheSize sets the cache size for sticky workflow cache. Sticky workflow execution is the affinity between decision tasks of a specific workflow execution to a specific worker. The affinity is set if sticky execution is enabled via Worker.Options (It is enabled by default unless disabled explicitly). The benefit of sticky execution is that workflow does not have to reconstruct the state by replaying from beginning of history events. But the cost is it consumes more memory as it rely on caching workflow execution's running state on the worker. The cache is shared between workers running within same process. This must be called before any worker is started. If not called, the default size of 10K (might change in future) will be used.

type NonDeterministicWorkflowPolicy Uses

type NonDeterministicWorkflowPolicy = internal.NonDeterministicWorkflowPolicy

NonDeterministicWorkflowPolicy is an enum for configuring how client's decision task handler deals with mismatched history events (presumably arising from non-deterministic workflow definitions).

type Options Uses

type Options = internal.WorkerOptions

Options is used to configure a worker instance.

type Worker Uses

type Worker interface {
    // RegisterWorkflow - registers a workflow function with the worker.
    // A workflow takes a workflow.Context and input and returns a (result, error) or just error.
    // Examples:
    //	func sampleWorkflow(ctx workflow.Context, input []byte) (result []byte, err error)
    //	func sampleWorkflow(ctx workflow.Context, arg1 int, arg2 string) (result []byte, err error)
    //	func sampleWorkflow(ctx workflow.Context) (result []byte, err error)
    //	func sampleWorkflow(ctx workflow.Context, arg1 int) (result string, err error)
    // Serialization of all primitive types, structures is supported ... except channels, functions, variadic, unsafe pointer.
    // For global registration consider workflow.Register
    // This method panics if workflowFunc doesn't comply with the expected format or tries to register the same workflow
    RegisterWorkflow(w interface{})

    // RegisterWorkflowWithOptions registers the workflow function with options.
    // The user can use options to provide an external name for the workflow or leave it empty if no
    // external name is required. This can be used as
    //  worker.RegisterWorkflowWithOptions(sampleWorkflow, RegisterWorkflowOptions{})
    //  worker.RegisterWorkflowWithOptions(sampleWorkflow, RegisterWorkflowOptions{Name: "foo"})
    // This method panics if workflowFunc doesn't comply with the expected format or tries to register the same workflow
    // type name twice. Use workflow.RegisterOptions.DisableAlreadyRegisteredCheck to allow multiple registrations.
    RegisterWorkflowWithOptions(w interface{}, options workflow.RegisterOptions)

    // RegisterActivity - register an activity function or a pointer to a structure with the worker.
    // An activity function takes a context and input and returns a (result, error) or just error.
    //
    // And activity struct is a structure with all its exported methods treated as activities. The default
    // name of each activity is the method name.
    //
    // Examples:
    //	func sampleActivity(ctx context.Context, input []byte) (result []byte, err error)
    //	func sampleActivity(ctx context.Context, arg1 int, arg2 string) (result *customerStruct, err error)
    //	func sampleActivity(ctx context.Context) (err error)
    //	func sampleActivity() (result string, err error)
    //	func sampleActivity(arg1 bool) (result int, err error)
    //	func sampleActivity(arg1 bool) (err error)
    //
    //  type Activities struct {
    //     // fields
    //  }
    //  func (a *Activities) SampleActivity1(ctx context.Context, arg1 int, arg2 string) (result *customerStruct, err error) {
    //    ...
    //  }
    //
    //  func (a *Activities) SampleActivity2(ctx context.Context, arg1 int, arg2 *customerStruct) (result string, err error) {
    //    ...
    //  }
    //
    // Serialization of all primitive types, structures is supported ... except channels, functions, variadic, unsafe pointer.
    // This method panics if activityFunc doesn't comply with the expected format or an activity with the same
    // type name is registered more than once.
    // For global registration consider activity.Register
    RegisterActivity(a interface{})

    // RegisterActivityWithOptions registers the activity function or struct pointer with options.
    // The user can use options to provide an external name for the activity or leave it empty if no
    // external name is required. This can be used as
    //  worker.RegisterActivityWithOptions(barActivity, RegisterActivityOptions{})
    //  worker.RegisterActivityWithOptions(barActivity, RegisterActivityOptions{Name: "barExternal"})
    // When registering the structure that implements activities the name is used as a prefix that is
    // prepended to the activity method name.
    //  worker.RegisterActivityWithOptions(&Activities{ ... }, RegisterActivityOptions{Name: "MyActivities_"})
    // To override each name of activities defined through a structure register the methods one by one:
    // activities := &Activities{ ... }
    // worker.RegisterActivityWithOptions(activities.SampleActivity1, RegisterActivityOptions{Name: "Sample1"})
    // worker.RegisterActivityWithOptions(activities.SampleActivity2, RegisterActivityOptions{Name: "Sample2"})
    // See RegisterActivity function for more info.
    // The other use of options is to disable duplicated activity registration check
    // which might be useful for integration tests.
    // worker.RegisterActivityWithOptions(barActivity, RegisterActivityOptions{DisableAlreadyRegisteredCheck: true})
    RegisterActivityWithOptions(a interface{}, options activity.RegisterOptions)

    // Start starts the worker in a non-blocking fashion
    Start() error
    // Run is a blocking start and cleans up resources when killed
    // returns error only if it fails to start the worker
    Run() error
    // Stop cleans up any resources opened by worker
    Stop()
}

Worker hosts workflow and activity implementations. Use worker.New(...) to create an instance.

func New Uses

func New(
    service workflowserviceclient.Interface,
    domain string,
    taskList string,
    options Options,
) Worker

New creates an instance of worker for managing workflow and activity executions.

service  - thrift connection to the cadence server
domain   - the name of the cadence domain
taskList - is the task list name you use to identify your client worker, also
           identifies group of workflow and activity implementations that are
           hosted by a single worker process
options  - configure any worker specific options like logger, metrics, identity

type WorkflowReplayer Uses

type WorkflowReplayer interface {

    // RegisterWorkflow registers workflow that is going to be replayed
    RegisterWorkflow(w interface{})

    // RegisterWorkflowWithOptions registers workflow that is going to be replayed with user provided name
    RegisterWorkflowWithOptions(w interface{}, options workflow.RegisterOptions)

    // ReplayWorkflowHistory executes a single decision task for the given json history file.
    // Use for testing the backwards compatibility of code changes and troubleshooting workflows in a debugger.
    // The logger is an optional parameter. Defaults to the noop logger.
    ReplayWorkflowHistory(logger *zap.Logger, history *shared.History) error

    // ReplayWorkflowHistoryFromJSONFile executes a single decision task for the json history file downloaded from the cli.
    // To download the history file: cadence workflow showid <workflow_id> -of <output_filename>
    // See https://github.com/uber/cadence/blob/master/tools/cli/README.md for full documentation
    // Use for testing the backwards compatibility of code changes and troubleshooting workflows in a debugger.
    // The logger is an optional parameter. Defaults to the noop logger.
    ReplayWorkflowHistoryFromJSONFile(logger *zap.Logger, jsonfileName string) error

    // ReplayPartialWorkflowHistoryFromJSONFile executes a single decision task for the json history file upto provided
    // lastEventID(inclusive), downloaded from the cli.
    // To download the history file: cadence workflow showid <workflow_id> -of <output_filename>
    // See https://github.com/uber/cadence/blob/master/tools/cli/README.md for full documentation
    // Use for testing the backwards compatibility of code changes and troubleshooting workflows in a debugger.
    // The logger is an optional parameter. Defaults to the noop logger.
    ReplayPartialWorkflowHistoryFromJSONFile(logger *zap.Logger, jsonfileName string, lastEventID int64) error

    // ReplayWorkflowExecution loads a workflow execution history from the Cadence service and executes a single decision task for it.
    // Use for testing the backwards compatibility of code changes and troubleshooting workflows in a debugger.
    // The logger is the only optional parameter. Defaults to the noop logger.
    ReplayWorkflowExecution(ctx context.Context, service workflowserviceclient.Interface, logger *zap.Logger, domain string, execution workflow.Execution) error
}

WorkflowReplayer supports replaying a workflow from its event history. Use for troubleshooting and backwards compatibility unit tests. For example if a workflow failed in production then its history can be downloaded through UI or CLI and replayed in a debugger as many times as necessary. Use this class to create unit tests that check if workflow changes are backwards compatible. It is important to maintain backwards compatibility through use of workflow.GetVersion to ensure that new deployments are not going to break open workflows.

func NewWorkflowReplayer Uses

func NewWorkflowReplayer() WorkflowReplayer

NewWorkflowReplayer creates a WorkflowReplayer instance.

Package worker imports 7 packages (graph) and is imported by 16 packages. Updated 2020-06-08. Refresh now. Tools for package owners.

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