SourceFunction API, which is due to be
removed. Use the new Source API instead.@Deprecated @Internal public class ContinuousFileMonitoringFunction<OUT> extends RichSourceFunction<TimestampedFileInputSplit> implements CheckpointedFunction
FileInputFormat and,
depending on the FileProcessingMode and the FilePathFilter, it is responsible
for:
splits corresponding to those files.
The splits to be read are forwarded to the downstream ContinuousFileReaderOperator
which can have parallelism greater than one.
IMPORTANT NOTE: Splits are forwarded downstream for reading in ascending modification time order, based on the modification time of the files they belong to.
SourceFunction.SourceContext<T>| Modifier and Type | Field and Description |
|---|---|
static long |
MIN_MONITORING_INTERVAL
Deprecated.
The minimum interval allowed between consecutive path scans.
|
| Constructor and Description |
|---|
ContinuousFileMonitoringFunction(FileInputFormat<OUT> format,
FileProcessingMode watchType,
int readerParallelism,
long interval)
Deprecated.
|
| Modifier and Type | Method and Description |
|---|---|
void |
cancel()
Deprecated.
Cancels the source.
|
void |
close()
Deprecated.
Tear-down method for the user code.
|
long |
getGlobalModificationTime()
Deprecated.
|
void |
initializeState(FunctionInitializationContext context)
Deprecated.
This method is called when the parallel function instance is created during distributed
execution.
|
void |
open(OpenContext openContext)
Deprecated.
Initialization method for the function.
|
void |
run(SourceFunction.SourceContext<TimestampedFileInputSplit> context)
Deprecated.
Starts the source.
|
void |
snapshotState(FunctionSnapshotContext context)
Deprecated.
This method is called when a snapshot for a checkpoint is requested.
|
getIterationRuntimeContext, getRuntimeContext, open, setRuntimeContextpublic static final long MIN_MONITORING_INTERVAL
NOTE: Only applicable to the PROCESS_CONTINUOUSLY mode.
public ContinuousFileMonitoringFunction(FileInputFormat<OUT> format, FileProcessingMode watchType, int readerParallelism, long interval)
@VisibleForTesting public long getGlobalModificationTime()
public void initializeState(FunctionInitializationContext context) throws Exception
CheckpointedFunctioninitializeState in interface CheckpointedFunctioncontext - the context for initializing the operatorException - Thrown, if state could not be created ot restored.public void open(OpenContext openContext) throws Exception
RichFunctionThe openContext object passed to the function can be used for configuration and initialization. The openContext contains some necessary information that were configured on the function in the program composition.
public class MyFilter extends RichFilterFunction<String> {
private String searchString;
public void open(OpenContext openContext) {
// initialize the value of searchString
}
public boolean filter(String value) {
return value.equals(searchString);
}
}
By default, this method does nothing.
1. If you implement open(OpenContext openContext), the open(OpenContext
openContext) will be invoked and the open(Configuration parameters) won't be
invoked. 2. If you don't implement open(OpenContext openContext), the open(Configuration parameters) will be invoked in the default implementation of the open(OpenContext openContext).
open in interface RichFunctionopenContext - The context containing information about the context in which the function
is opened.Exception - Implementations may forward exceptions, which are caught by the runtime.
When the runtime catches an exception, it aborts the task and lets the fail-over logic
decide whether to retry the task execution.public void run(SourceFunction.SourceContext<TimestampedFileInputSplit> context) throws Exception
SourceFunctionSourceFunction.SourceContext to emit elements. Sources
that checkpoint their state for fault tolerance should use the checkpoint lock to ensure consistency between the
bookkeeping and emitting the elements.
Sources that implement CheckpointedFunction must lock on the checkpoint lock checkpoint lock (using a synchronized
block) before updating internal state and emitting elements, to make both an atomic
operation.
Refer to the top-level class docs for an example.
run in interface SourceFunction<TimestampedFileInputSplit>context - The context to emit elements to and for accessing locks.Exceptionpublic void close()
throws Exception
RichFunctionThis method can be used for clean up work.
close in interface RichFunctionclose in class AbstractRichFunctionException - Implementations may forward exceptions, which are caught by the runtime.
When the runtime catches an exception, it aborts the task and lets the fail-over logic
decide whether to retry the task execution.public void cancel()
SourceFunctionSourceFunction.run(SourceContext) method. The implementation needs to ensure that the source will break
out of that loop after this method is called.
A typical pattern is to have an "volatile boolean isRunning" flag that is set to
false in this method. That flag is checked in the loop condition.
In case of an ungraceful shutdown (cancellation of the source operator, possibly for
failover), the thread that calls SourceFunction.run(SourceContext) will also be interrupted) by the Flink runtime, in order to speed up the cancellation
(to ensure threads exit blocking methods fast, like I/O, blocking queues, etc.). The
interruption happens strictly after this method has been called, so any interruption handler
can rely on the fact that this method has completed (for example to ignore exceptions that
happen after cancellation).
During graceful shutdown (for example stopping a job with a savepoint), the program must
cleanly exit the SourceFunction.run(SourceContext) method soon after this method was called. The
Flink runtime will NOT interrupt the source thread during graceful shutdown. Source
implementors must ensure that no thread interruption happens on any thread that emits records
through the SourceContext from the SourceFunction.run(SourceContext) method; otherwise the
clean shutdown may fail when threads are interrupted while processing the final records.
Because the SourceFunction cannot easily differentiate whether the shutdown should
be graceful or ungraceful, we recommend that implementors refrain from interrupting any
threads that interact with the SourceContext at all. You can rely on the Flink
runtime to interrupt the source thread in case of ungraceful cancellation. Any additionally
spawned threads that directly emit records through the SourceContext should use a
shutdown method that does not rely on thread interruption.
cancel in interface SourceFunction<TimestampedFileInputSplit>public void snapshotState(FunctionSnapshotContext context) throws Exception
CheckpointedFunctionFunctionInitializationContext when the Function was initialized, or offered now by FunctionSnapshotContext itself.snapshotState in interface CheckpointedFunctioncontext - the context for drawing a snapshot of the operatorException - Thrown, if state could not be created ot restored.Copyright © 2014–2024 The Apache Software Foundation. All rights reserved.