Class OtlpOutput

java.lang.Object

io.jstach.rainbowgum.otlp.OtlpOutput

All Implemented Interfaces:

LogLifecycle, LogOutput, LogOutput.ProvidesEncoder, Flushable, AutoCloseable

public final class OtlpOutput
extends Object
implements LogOutput, LogOutput.ProvidesEncoder

Sends log events to an OTLP/HTTP endpoint (/v1/logs) as protobuf (the default) or JSON, without the OpenTelemetry SDK or a protobuf library.

Events are buffered and sent as one request per flush(), and as soon as maxBatchSize events are pending. Use an asynchronous publisher: with the default synchronous one every log call waits for its own HTTP request. HTTP 429, 502, 503, and 504 responses and network errors are retried up to three times with exponential backoff with jitter, honoring Retry-After. The timeout bounds the whole export, including retries and response-body reads. A batch that still fails is dropped, recorded as an error alert, and counted in "otlp.records.failed". Records the endpoint reports as rejected (partial success) are a warning alert and counted in "otlp.records.rejected".

This output encodes events itself, so it does not use an appender encoder. Records have the same content as OtlpJsonEncoder produces.

Nested Class Summary

Nested classes/interfaces inherited from interface LogOutput

LogOutput.AbstractOutputStreamOutput, LogOutput.ContentType, LogOutput.OutputProvider, LogOutput.OutputType, LogOutput.ProvidesEncoder, LogOutput.ThreadSafeLogOutput, LogOutput.WriteMethod

Modifier and Type	Interface	Description
static class	LogOutput.AbstractOutputStreamOutput	Abstract output on output stream.
static interface	LogOutput.ContentType	The content type of the binary data passed to the output from an encoder.
static interface	LogOutput.OutputProvider	Finds output based on URI.
static enum	LogOutput.OutputType	Output type useful for defaults and categorization.
static interface	LogOutput.ProvidesEncoder	Marks an output that supplies its own LogEncoder instead of relying entirely on LogAppender.APPENDER_ENCODER_PROPERTY or LogEncoderRegistry.encoderForOutputType(OutputType).
static interface	LogOutput.ThreadSafeLogOutput	Marker interface that the output is thread safe.
static enum	LogOutput.WriteMethod	The preferred write style of an output.

Nested classes/interfaces inherited from interface LogOutput.ProvidesEncoder

LogOutput.ProvidesEncoder.Policy

Modifier and Type	Interface	Description
static enum	LogOutput.ProvidesEncoder.Policy	Whether a LogOutput.ProvidesEncoder's LogOutput.ProvidesEncoder.encoder(String, LogConfig) can be overridden by another, explicitly configured encoder.

Field Summary

Fields

Modifier and Type	Field	Description
static final int	DEFAULT_MAX_BATCH_SIZE	Default maximum number of events per request.
static final int	DEFAULT_TIMEOUT	Default export timeout in milliseconds.
static final String	FAILED_METRIC	Metric counting log records dropped because a request failed.
static final String	OTLP_SCHEME	Output URI scheme.
static final String	REJECTED_METRIC	Metric counting log records the endpoint rejected in a partial success response.

Fields inherited from interface LogOutput

FILE_SCHEME, STDERR_SCHEME, STDERR_URI, STDOUT_SCHEME, STDOUT_URI

Modifier and Type	Field	Description
static final String	FILE_SCHEME	File URI scheme.
static final String	STDERR_SCHEME	FileDescriptor.err URI scheme.
static final URI	STDERR_URI	Standard ERR URI
static final String	STDOUT_SCHEME	FileDescriptor.out URI scheme.
static final URI	STDOUT_URI	Standard OUT URI.

Method Summary

Modifier and Type	Method	Description
void	close()	Will close the output and should only be called by the owning appender.
LogEncoder	encoder(String name, LogConfig config)	The encoder this output supplies, given the same name/config the output itself was provided with.
URI	endpoint()	The endpoint requests are sent to.
void	flush()	Flushes if the output is maintaining a buffer.
static LogProvider<OtlpOutput>	of(Consumer<OtlpOutputBuilder> consumer)	Creates the output with a builder lambda; properties are applied after the lambda.
LogOutput.ProvidesEncoder.Policy	policy()	Whether LogOutput.ProvidesEncoder.encoder(String, LogConfig) can be overridden by an explicitly configured encoder.
OtlpProtocol	protocol()	The payload encoding.
LogOutput.OutputType	type()	Gross categorization of an output.
URI	uri()	The uri of the output.
void	write(LogEvent[] events, int count, LogEncoder encoder, LogEncoder.Buffer buffer)	Write a batch of events reusing the provided buffer and by default calling LogOutput.write(LogEvent, Buffer) for each event synchronously.
void	write(LogEvent event, byte[] bytes, int off, int len, LogOutput.ContentType contentType)	Analogous to OutputStream.write(byte[], int, int).

Methods inherited from class Object

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

Methods inherited from interface LogOutput

bufferHints, reopen, start, write, write, write, write, write

Modifier and Type	Method	Description
default LogEncoder.BufferHints	bufferHints()	Hints to the buffer like what write style of the output and maximum buffer size.
default void	reopen()	Attempts to reopen the output if supported and SHOULD only be called by the appender!
default void	start(LogConfig config)	Starts a component.
default void	write(LogEvent[] events, int count, LogEncoder encoder)	Write a batch of events by default calls LogOutput.write(LogEvent[], int, LogEncoder, Buffer).
default void	write(LogEvent event, byte[] bytes, LogOutput.ContentType contentType)	Analogous to OutputStream.write(byte[]).
default void	write(LogEvent event, LogEncoder.Buffer buffer)	Writes a prepared buffer and by default drains the buffer to this output.
default void	write(LogEvent event, String s)	Writes a string and by default with charset StandardCharsets.UTF_8.
default void	write(LogEvent event, ByteBuffer buf, LogOutput.ContentType contentType)	Write event with byte buffer.

Field Details

OTLP_SCHEME

public static final String OTLP_SCHEME

Output URI scheme.

See Also:

• Constant Field Values

FAILED_METRIC

public static final String FAILED_METRIC

Metric counting log records dropped because a request failed.

See Also:

• Constant Field Values

REJECTED_METRIC

public static final String REJECTED_METRIC

Metric counting log records the endpoint rejected in a partial success response.

See Also:

• Constant Field Values

DEFAULT_MAX_BATCH_SIZE

public static final int DEFAULT_MAX_BATCH_SIZE

Default maximum number of events per request.

See Also:

• Constant Field Values

DEFAULT_TIMEOUT

public static final int DEFAULT_TIMEOUT

Default export timeout in milliseconds.

See Also:

• Constant Field Values

Method Details

of

public static LogProvider<OtlpOutput> of(Consumer<OtlpOutputBuilder> consumer)

Creates the output with a builder lambda; properties are applied after the lambda.

Parameters:

consumer - configures the builder.

Returns:

output provider.

endpoint

public URI endpoint()

The endpoint requests are sent to.

Returns:

endpoint URL.

protocol

public OtlpProtocol protocol()

The payload encoding.

Returns:

protocol.

uri

public URI uri()

Description copied from interface: LogOutput

The uri of the output.

Specified by:

uri in interface LogOutput

Returns:

uri.

type

public LogOutput.OutputType type()

Description copied from interface: LogOutput

Gross categorization of an output.

Specified by:

type in interface LogOutput

Returns:

output type.

encoder

public LogEncoder encoder(String name,
 LogConfig config)

Description copied from interface: LogOutput.ProvidesEncoder

The encoder this output supplies, given the same name/config the output itself was provided with.

Specified by:

encoder in interface LogOutput.ProvidesEncoder

Parameters:

name - appender name.

config - config.

Returns:

encoder, see LogOutput.ProvidesEncoder.policy() for whether it can be overridden.

policy

public LogOutput.ProvidesEncoder.Policy policy()

Description copied from interface: LogOutput.ProvidesEncoder

Whether LogOutput.ProvidesEncoder.encoder(String, LogConfig) can be overridden by an explicitly configured encoder. Defaults to LogOutput.ProvidesEncoder.Policy.DEFAULT - an implementation only needs to override this to return LogOutput.ProvidesEncoder.Policy.MANDATORY.

Specified by:

policy in interface LogOutput.ProvidesEncoder

Returns:

policy.

write

public void write(LogEvent event,
 byte[] bytes,
 int off,
 int len,
 LogOutput.ContentType contentType)

Description copied from interface: LogOutput

Analogous to OutputStream.write(byte[], int, int).

Specified by:

write in interface LogOutput

Parameters:

event - event associated with bytes.

bytes - data to be written.

off - offset.

len - length.

contentType - content type of the bytes.

write

public void write(LogEvent[] events,
 int count,
 LogEncoder encoder,
 LogEncoder.Buffer buffer)

Description copied from interface: LogOutput

Write a batch of events reusing the provided buffer and by default calling LogOutput.write(LogEvent, Buffer) for each event synchronously.

The batching is usually a result of an asynchronous publisher so the maximum size is configured there with bufferSize. If this method is implemented there are some caveats.

DO NOT MODIFY THE ARRAY. It is reused. Do not use the length of the passed in array but instead use count parameter. Consequently do not share the array or buffer with other threads however individual events can be shared by calling LogEvent.freeze() to guarantee that which is a safe no-op if it is already immutable.

If the output plans on grouping the events into a single blob (byte array or byte buffer) a different output can be passed to the encoder other than itself (which is the default).

Specified by:

write in interface LogOutput

Parameters:

events - an array guaranteed to be smaller than count.

count - the number of items.

encoder - encoder to use for encoding.

buffer - buffer to reuse. Do not share it with other threads!

flush

public void flush()

Description copied from interface: LogOutput

Flushes if the output is maintaining a buffer. By default an appender will call this after each event in synchronous mode or after a batched group of events if in asynchronous mode unless LogAppender.AppenderFlag.DISABLE_IMMEDIATE_FLUSH is set.

Specified by:

flush in interface Flushable

Specified by:

flush in interface LogOutput

See Also:

• LogAppender.AppenderFlag.DISABLE_IMMEDIATE_FLUSH

close

public void close()

Description copied from interface: LogOutput

Will close the output and should only be called by the owning appender.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface LogLifecycle

Specified by:

close in interface LogOutput