WorkProgressUpdater (Google Cloud Dataflow SDK 1.0.0 API)

java.lang.Object
- com.google.cloud.dataflow.sdk.util.common.worker.WorkProgressUpdater

Direct Known Subclasses:

DataflowWorkProgressUpdater
```
@NotThreadSafe
public abstract class WorkProgressUpdater
extends Object
```
WorkProgressUpdater allows a work executor to send work progress updates to the worker service. The life-cycle of the WorkProgressUpdater is controlled externally through its startReportingProgress() and stopReportingProgress() methods. The updater queries the worker for progress updates and sends the updates to the worker service. The interval between two consecutive updates is controlled by the worker service through reporting interval hints sent back in the update response messages. To avoid update storms and monitoring staleness, the interval between two consecutive updates is also bound by getMinReportingInterval() and getMaxReportingInterval().

Field Summary

Fields
Modifier and Type	Field and Description
`static long`	`DEFAULT_LEASE_DURATION_MILLIS` The default lease duration to request from the external worker service (3 minutes).
`protected Reader.DynamicSplitResult`	`dynamicSplitResultToReport` The `Reader.DynamicSplitResult` to report to the service in the next progress update, or `null` if there is nothing to report (if no dynamic split happened since the last progress update).
`protected long`	`progressReportIntervalMs` The time period until the next work progress update.
`protected long`	`requestedLeaseDurationMs` The lease duration to request from the external worker service.
`protected WorkExecutor`	`worker` Worker providing the work progress updates.

Constructor Summary

Constructors
Constructor and Description

WorkProgressUpdater(WorkExecutor worker)

Constructors
Constructor and Description
`WorkProgressUpdater(WorkExecutor worker)`

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`Reader.DynamicSplitResult`	`getDynamicSplitResultToReport()`
`protected long`	`getLeaseRenewalLatencyMargin()` Returns the maximum allowed time between a periodic progress update and the moment the current lease expires.
`protected long`	`getMaxReportingInterval()` Returns the maximum allowed time between two periodic progress updates.
`protected long`	`getMinReportingInterval()` Returns the minimum allowed time between two periodic progress updates.
`protected abstract long`	`getWorkUnitLeaseExpirationTimestamp()` Returns the current work item's lease expiration timestamp.
`protected long`	`getWorkUnitSuggestedReportingInterval()` Returns the current work item's suggested progress reporting interval.
`protected long`	`leaseRemainingTime(long leaseExpirationTimestamp)` Computes the amount of time left, in milliseconds, before a lease with the specified expiration timestamp expires.
`protected long`	`nextProgressReportInterval(long suggestedInterval, long leaseRemainingTime)` Computes the time before sending the next work progress update making sure that it falls between the [`getMinReportingInterval()`, `getMaxReportingInterval()`] interval.
`protected abstract void`	`reportProgressHelper()` Reports the current work progress to the worker service.
`void`	`startReportingProgress()` Starts sending work progress updates to the worker service.
`void`	`stopReportingProgress()` Stops sending work progress updates to the worker service.
`protected abstract String`	`workString()` Returns a string representation of the work item whose progress is being updated, for use in logging messages.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - DEFAULT_LEASE_DURATION_MILLIS
```
public static final long DEFAULT_LEASE_DURATION_MILLIS
```
    The default lease duration to request from the external worker service (3 minutes).
    
    See Also:
    
    Constant Field Values
  - worker
```
protected final WorkExecutor worker
```
    Worker providing the work progress updates.
  - requestedLeaseDurationMs
```
protected long requestedLeaseDurationMs
```
    The lease duration to request from the external worker service.
  - progressReportIntervalMs
```
protected long progressReportIntervalMs
```
    The time period until the next work progress update.
  - dynamicSplitResultToReport
```
protected Reader.DynamicSplitResult dynamicSplitResultToReport
```
    The Reader.DynamicSplitResult to report to the service in the next progress update, or null if there is nothing to report (if no dynamic split happened since the last progress update).
- Constructor Detail
  - WorkProgressUpdater
```
public WorkProgressUpdater(WorkExecutor worker)
```
- Method Detail
  - startReportingProgress
```
public void startReportingProgress()
```
    Starts sending work progress updates to the worker service.
  - stopReportingProgress
```
public void stopReportingProgress()
                           throws Exception
```
    Stops sending work progress updates to the worker service. It may throw an exception if the final progress report fails to be sent for some reason.
    
    Throws:
    
    Exception
  - nextProgressReportInterval
```
protected final long nextProgressReportInterval(long suggestedInterval,
                                                long leaseRemainingTime)
```
    Computes the time before sending the next work progress update making sure that it falls between the [getMinReportingInterval(), getMaxReportingInterval()] interval. Makes an attempt to bound the result by the remaining lease time, with an RPC latency margin of getLeaseRenewalLatencyMargin().
    
    Parameters:
    
    suggestedInterval - the suggested progress report interval
    
    leaseRemainingTime - milliseconds left before the work lease expires
    
    Returns:
    
    the time in milliseconds before sending the next progress update
  - leaseRemainingTime
```
protected long leaseRemainingTime(long leaseExpirationTimestamp)
```
    Computes the amount of time left, in milliseconds, before a lease with the specified expiration timestamp expires. Returns zero if the lease has already expired.
  - getDynamicSplitResultToReport
```
public Reader.DynamicSplitResult getDynamicSplitResultToReport()
```
  - reportProgressHelper
```
protected abstract void reportProgressHelper()
                                      throws Exception
```
    Reports the current work progress to the worker service.
    
    Throws:
    
    Exception
  - getWorkUnitLeaseExpirationTimestamp
```
protected abstract long getWorkUnitLeaseExpirationTimestamp()
```
    Returns the current work item's lease expiration timestamp.
  - getWorkUnitSuggestedReportingInterval
```
protected long getWorkUnitSuggestedReportingInterval()
```
    Returns the current work item's suggested progress reporting interval.
  - getMinReportingInterval
```
protected long getMinReportingInterval()
```
    Returns the minimum allowed time between two periodic progress updates.
  - getMaxReportingInterval
```
protected long getMaxReportingInterval()
```
    Returns the maximum allowed time between two periodic progress updates.
  - getLeaseRenewalLatencyMargin
```
protected long getLeaseRenewalLatencyMargin()
```
    Returns the maximum allowed time between a periodic progress update and the moment the current lease expires.
  - workString
```
protected abstract String workString()
```
    Returns a string representation of the work item whose progress is being updated, for use in logging messages.

Class WorkProgressUpdater

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

DEFAULT_LEASE_DURATION_MILLIS

worker

requestedLeaseDurationMs

progressReportIntervalMs

dynamicSplitResultToReport

Constructor Detail

WorkProgressUpdater

Method Detail

startReportingProgress

stopReportingProgress

nextProgressReportInterval

leaseRemainingTime

getDynamicSplitResultToReport

reportProgressHelper

getWorkUnitLeaseExpirationTimestamp

getWorkUnitSuggestedReportingInterval

getMinReportingInterval

getMaxReportingInterval

getLeaseRenewalLatencyMargin

workString