com.kdgregory.logging.aws.cloudwatch

Class CloudWatchLogWriter

java.lang.Object

com.kdgregory.logging.aws.internal.AbstractLogWriter<CloudWatchWriterConfig,CloudWatchWriterStatistics>

com.kdgregory.logging.aws.cloudwatch.CloudWatchLogWriter

All Implemented Interfaces:

LogWriter, Runnable

public class CloudWatchLogWriter
extends AbstractLogWriter<CloudWatchWriterConfig,CloudWatchWriterStatistics>

Writes messages to a CloudWatch log stream. Auto-create both group and stream if they do not exist, and re-creates them if they're deleted during operation.

Implementation note: the various retry managers are exposed so that tests can replace them with shorter delays.

Field Summary

Fields

Modifier and Type	Field and Description
protected RetryManager2	createRetry
protected RetryManager2	describeRetry
protected RetryManager2	sendRetry
protected Duration	sendTimeout

Fields inherited from class com.kdgregory.logging.aws.internal.AbstractLogWriter

config, logger, stats

Constructor Summary

Constructors

Constructor and Description
CloudWatchLogWriter(CloudWatchWriterConfig config, CloudWatchWriterStatistics stats, InternalLogger logger, CloudWatchFacade facade)

Method Summary

Modifier and Type	Method and Description
protected int	effectiveSize(LogMessage message) Calculates the effective size of the message.
protected boolean	ensureDestinationAvailable() Verifies that the logging destination is available (which may involve creating it).
int	maxMessageSize() Returns the maximum allowed UTF-8 message size for the destination.
protected List<LogMessage>	sendBatch(List<LogMessage> batch) Sends a batch of messages.
protected void	stopAWSClient() This is called when the logwriter is stopped, to explicitly close the AWS service client.
protected boolean	withinServiceLimits(int batchBytes, int numMessages) Determines whether the provided batch size or number of messages would exceed the service's limits.

Methods inherited from class com.kdgregory.logging.aws.internal.AbstractLogWriter

addMessage, buildBatch, getBatchCount, getBatchDelay, initialize, isRunning, isSynchronous, keepRunning, processBatch, reportError, run, setBatchDelay, setDiscardAction, setDiscardThreshold, stop, waitUntilInitialized, waitUntilStopped

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

describeRetry

protected RetryManager2 describeRetry

createRetry

protected RetryManager2 createRetry

sendTimeout

protected Duration sendTimeout

sendRetry

protected RetryManager2 sendRetry

Constructor Detail

CloudWatchLogWriter

public CloudWatchLogWriter(CloudWatchWriterConfig config,
                           CloudWatchWriterStatistics stats,
                           InternalLogger logger,
                           CloudWatchFacade facade)

Method Detail

maxMessageSize

public int maxMessageSize()

Description copied from interface: LogWriter

Returns the maximum allowed UTF-8 message size for the destination.

ensureDestinationAvailable

protected boolean ensureDestinationAvailable()

Description copied from class: AbstractLogWriter

Verifies that the logging destination is available (which may involve creating it). Return true if successful, false if not (which will cause the appender to stop running).

Specified by:

ensureDestinationAvailable in class AbstractLogWriter<CloudWatchWriterConfig,CloudWatchWriterStatistics>

sendBatch

protected List<LogMessage> sendBatch(List<LogMessage> batch)

Description copied from class: AbstractLogWriter

Sends a batch of messages. The subclass is responsible for returning any messages that weren't sent, in order, so that they can be requeued.

Specified by:

sendBatch in class AbstractLogWriter<CloudWatchWriterConfig,CloudWatchWriterStatistics>

effectiveSize

protected int effectiveSize(LogMessage message)

Description copied from class: AbstractLogWriter

Calculates the effective size of the message. This includes the message bytes plus any overhead. It is used to calculate the number of bytes the message will add to a batch.

Specified by:

effectiveSize in class AbstractLogWriter<CloudWatchWriterConfig,CloudWatchWriterStatistics>

withinServiceLimits

protected boolean withinServiceLimits(int batchBytes,
                                      int numMessages)

Description copied from class: AbstractLogWriter

Determines whether the provided batch size or number of messages would exceed the service's limits.

Specified by:

withinServiceLimits in class AbstractLogWriter<CloudWatchWriterConfig,CloudWatchWriterStatistics>

stopAWSClient

protected void stopAWSClient()

Description copied from class: AbstractLogWriter

This is called when the logwriter is stopped, to explicitly close the AWS service client. It must be implemented by the subclass because we don't know the actual type and there's no abstract super-interface.

Specified by:

stopAWSClient in class AbstractLogWriter<CloudWatchWriterConfig,CloudWatchWriterStatistics>