https://github.com/Netflix/Hystrix: hystrix-core
  • Netflix Open Source Development 
Copyright 2012 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.
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/**
 * Copyright 2012 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.hystrix.strategy.metrics;

import com.netflix.hystrix.HystrixCollapser;


Metrics publisher for a HystrixCollapser that will be constructed by an implementation of HystrixMetricsPublisher. 

Instantiation of implementations of this interface should NOT allocate resources that require shutdown, register listeners or other such global state changes.


The initialize() method will be called once-and-only-once to indicate when this instance can register with external services, start publishing metrics etc.


Doing this logic in the constructor could result in memory leaks, double-publishing and other such behavior because this can be optimistically constructed more than once and "extras" discarded with
only one actually having initialize() called on it.

/**
 * Metrics publisher for a {@link HystrixCollapser} that will be constructed by an implementation of {@link HystrixMetricsPublisher}.
 * <p>
 * Instantiation of implementations of this interface should NOT allocate resources that require shutdown, register listeners or other such global state changes.
 * <p>
 * The <code>initialize()</code> method will be called once-and-only-once to indicate when this instance can register with external services, start publishing metrics etc.
 * <p>
 * Doing this logic in the constructor could result in memory leaks, double-publishing and other such behavior because this can be optimistically constructed more than once and "extras" discarded with
 * only one actually having <code>initialize()</code> called on it.
 */
public interface HystrixMetricsPublisherCollapser {

    // TODO should the arguments be given via initialize rather than constructor so people can't accidentally do it wrong?

    public void initialize();

}