com.netflix.genie.common.internal.tracing.TracePropagator Maven / Gradle / Ivy
/*
*
* Copyright 2021 Netflix, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package com.netflix.genie.common.internal.tracing;
import java.util.Map;
import java.util.Optional;
/**
* This interface exists to provide a shared contract for how trace information is shared between the Genie
* server job request handling and the agent process launch. Implementations should be shared across server and agent
* versions for compatibility.
*
* Note: This somewhat copies a pattern from Brave however it is
* purposely decoupled so as to allow other implementations if necessary.
*
* @param The trace context type that should be used for injection and returned from extraction
* @author tgianos
* @since 4.0.0
*/
public interface TracePropagator {
/**
* Extract the trace context from the supplied set of key value pairs.
*
* Implementations should swallow all exceptions as tracing is not critical to the completion of a job on behalf
* of the user.
*
* @param environment Generally this will be the result of {@link System#getenv()}
* @return A new instance of {@link C} containing the extracted context or {@link Optional#empty()} if no context
* information was found
*/
Optional extract(Map environment);
/**
* Inject the trace context from {@literal U} into the returned set of key value pairs for propagation to Agent.
*
* Implementations should swallow all exceptions as tracing is not critical to the completion of a job on behalf
* of the user.
*
* @param traceContext The context for the active unit of work (span in Brave parlance)
* @return A set of key value pairs that should be propagated to the agent in some manner to be extracted in
* {@link #extract(Map)}
*/
Map injectForAgent(C traceContext);
/**
* Inject the trace context from {@literal U} into the returned set of key value pairs for propagation to job.
*
* Implementations should swallow all exceptions as tracing is not critical to the completion of a job on behalf
* of the user.
*
* @param traceContext The context for the active unit of work (span in Brave parlance)
* @return A set of key value pairs that should be propagated to the job in some manner which can be extracted
* by downstream systems if they so desire
*/
Map injectForJob(C traceContext);
}