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@@ -96,25 +96,10 @@ $(addBlockSwitches);
<div id="toctitle">Table of Contents</div>
<ul class="sectlevel0">
<li><a href="#_spring_cloud_circuit_breaker">Spring Cloud Circuit Breaker</a>
<ul class="sectlevel1">
<li><a href="#_introduction">Introduction</a>
<ul class="sectlevel2">
<li><a href="#_supported_implementations">Supported Implementations</a></li>
</ul>
</li>
<li><a href="#_core_concepts">Core Concepts</a>
<ul class="sectlevel2">
<li><a href="#_circuit_breakers_in_reactive_code">Circuit Breakers In Reactive Code</a></li>
</ul>
</li>
<li><a href="#_configuration">Configuration</a>
<ul class="sectlevel2">
<li><a href="#_configuring_hystrix_circuit_breakers">Configuring Hystrix Circuit Breakers</a></li>
<li><a href="#_configuring_resilience4j_circuit_breakers">Configuring Resilience4J Circuit Breakers</a></li>
<li><a href="#_configuring_sentinel_circuit_breakers">Configuring Sentinel Circuit Breakers</a></li>
<li><a href="#_configuring_spring_retry_circuit_breakers">Configuring Spring Retry Circuit Breakers</a></li>
</ul>
</li>
<li><a href="#_building">Building</a>
<ul class="sectlevel2">
<li><a href="#_basic_compile_and_test">Basic Compile and Test</a></li>
@@ -159,200 +144,7 @@ $(addBlockSwitches);
<h1 id="_spring_cloud_circuit_breaker" class="sect0"><a class="link" href="#_spring_cloud_circuit_breaker">Spring Cloud Circuit Breaker</a></h1>
<div class="openblock partintro">
<div class="content">
<strong>0.0.1.BUILD-SNAPSHOT</strong>
</div>
</div>
<div class="sect1">
<h2 id="_introduction"><a class="link" href="#_introduction">Introduction</a></h2>
<div class="sectionbody">
<div class="paragraph">
<p>Spring Cloud Circuit breaker provides an abstraction across different circuit breaker implementations.
It provides a consistent API to use in your applications allowing you the developer to choose the circuit
breaker implementation that best fits your needs for your app.</p>
</div>
<div class="sect2">
<h3 id="_supported_implementations"><a class="link" href="#_supported_implementations">Supported Implementations</a></h3>
<div class="ulist">
<ul>
<li>
<p><a href="https://github.com/Netflix/Hystrix">Netfix Hystrix</a></p>
</li>
<li>
<p><a href="https://github.com/resilience4j/resilience4j">Resilience4J</a></p>
</li>
<li>
<p><a href="https://github.com/alibaba/Sentinel">Sentinel</a></p>
</li>
<li>
<p><a href="https://github.com/spring-projects/spring-retry">Spring Retry</a></p>
</li>
</ul>
</div>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_core_concepts"><a class="link" href="#_core_concepts">Core Concepts</a></h2>
<div class="sectionbody">
<div class="paragraph">
<p>To create a circuit breaker in your code you can use the <code>CircuitBreakerFactory</code> API. When you include a Spring
Cloud Circuit Breaker starter on your classpath a bean implementing this API will automatically be created
for you. A very simple example of using this API is given below</p>
</div>
<div class="exampleblock">
<div class="content">
<div class="listingblock">
<div class="content">
<pre class="highlightjs highlight"><code class="language-java hljs" data-lang="java">@Service
public static class DemoControllerService {
private RestTemplate rest;
private CircuitBreakerFactory cbFactory;
public DemoControllerService(RestTemplate rest, CircuitBreakerFactory cbFactory) {
this.rest = rest;
this.cbFactory = cbFactory;
}
public String slow() {
return cbFactory.create("slow").run(() -&gt; rest.getForObject("/slow", String.class), throwable -&gt; "fallback");
}
}</code></pre>
</div>
</div>
</div>
</div>
<div class="paragraph">
<p>The <code>CircuitBreakerFactory.create</code> API will create an instance of a class called <code>CircuitBreaker</code>.
The <code>run</code> method takes a <code>Supplier</code> and a <code>Function</code>. The <code>Supplier</code> is the code that you are going to
wrap in a circuit breaker. The <code>Function</code> is the fallback that will be executed if the circuit
breaker is tripped. The function will be passed the <code>Throwable</code> that caused the fallback to be
triggered. You can optionally exclude the fallback if you do not want to provide one.</p>
</div>
<div class="sect2">
<h3 id="_circuit_breakers_in_reactive_code"><a class="link" href="#_circuit_breakers_in_reactive_code">Circuit Breakers In Reactive Code</a></h3>
<div class="paragraph">
<p>If Project Reactor is on the class path then you can also use <code>ReactiveCircuitBreakerFactory</code> for your reactive
code.</p>
</div>
<div class="exampleblock">
<div class="content">
<div class="listingblock">
<div class="content">
<pre class="highlightjs highlight"><code class="language-java hljs" data-lang="java">@Service
public static class DemoControllerService {
private ReactiveCircuitBreakerFactory cbFactory;
private WebClient webClient;
public DemoControllerService(WebClient webClient, ReactiveCircuitBreakerFactory cbFactory) {
this.webClient = webClient;
this.cbFactory = cbFactory;
}
public Mono&lt;String&gt; slow() {
return webClient.get().uri("/slow").retrieve().bodyToMono(String.class).transform(
it -&gt; cbFactory.create("slow").run(it, throwable -&gt; return Mono.just("fallback")));
}
}</code></pre>
</div>
</div>
</div>
</div>
<div class="paragraph">
<p>The <code>ReactiveCircuitBreakerFactory.create</code> API will create an instance of a class called <code>ReactiveCircuitBreaker</code>.
The <code>run</code> method takes with a <code>Mono</code> or <code>Flux</code> and wraps it in a circuit breaker. You can optionally profile
a fallback <code>Function</code> which will be called if the circuit breaker is tripped and will be passed the <code>Throwable</code>
that caused the failure.</p>
</div>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_configuration"><a class="link" href="#_configuration">Configuration</a></h2>
<div class="sectionbody">
<div class="paragraph">
<p>You can configure your circuit breakers using by creating beans of type <code>Customizer</code>. The <code>Customizer</code> interface
has a single method called <code>customize</code> that takes in the <code>Object</code> to customize.</p>
</div>
<div class="sect2">
<h3 id="_configuring_hystrix_circuit_breakers"><a class="link" href="#_configuring_hystrix_circuit_breakers">Configuring Hystrix Circuit Breakers</a></h3>
<div class="sect3">
<h4 id="_default_configuration"><a class="link" href="#_default_configuration">Default Configuration</a></h4>
<div class="paragraph">
<p>To provide a default configuration for all of your circuit breakers create a <code>Customize</code> bean that is passed a
<code>HystrixCircuitBreakerFactory</code> or <code>ReactiveHystrixCircuitBreakerFactory</code>.
The <code>configureDefault</code> method can be used to provide a default configuration.</p>
</div>
<div class="exampleblock">
<div class="content">
<div class="listingblock">
<div class="content">
<pre class="highlightjs highlight"><code class="language-java hljs" data-lang="java">@Bean
public Customizer&lt;HystrixCircuitBreakerFactory&gt; defaultConfig() {
return factory -&gt; factory.configureDefault(id -&gt; HystrixCommand.Setter
.withGroupKey(HystrixCommandGroupKey.Factory.asKey(id))
.andCommandPropertiesDefaults(HystrixCommandProperties.Setter()
.withExecutionTimeoutInMilliseconds(4000)));
}</code></pre>
</div>
</div>
</div>
</div>
<div class="sect4">
<h5 id="_reactive_example"><a class="link" href="#_reactive_example">Reactive Example</a></h5>
<div class="exampleblock">
<div class="content">
<div class="listingblock">
<div class="content">
<pre class="highlightjs highlight"><code class="language-java hljs" data-lang="java">@Bean
public Customizer&lt;ReactiveHystrixCircuitBreakerFactory&gt; defaultConfig() {
return factory -&gt; factory.configureDefault(id -&gt; HystrixObservableCommand.Setter
.withGroupKey(HystrixCommandGroupKey.Factory.asKey(id))
.andCommandPropertiesDefaults(HystrixCommandProperties.Setter()
.withExecutionTimeoutInMilliseconds(4000)));
}</code></pre>
</div>
</div>
</div>
</div>
</div>
</div>
<div class="sect3">
<h4 id="_specific_circuit_breaker_configuration"><a class="link" href="#_specific_circuit_breaker_configuration">Specific Circuit Breaker Configuration</a></h4>
<div class="paragraph">
<p>Similarly to providing a default configuration, you can create a <code>Customize</code> bean this is passed a
<code>HystrixCircuitBreakerFactory</code></p>
</div>
<div class="exampleblock">
<div class="content">
<div class="listingblock">
<div class="content">
<pre class="highlightjs highlight"><code class="language-java hljs" data-lang="java">@Bean
public Customizer&lt;HystrixCircuitBreakerFactory&gt; customizer() {
return factory -&gt; factory.configure(builder -&gt; builder.commandProperties(
HystrixCommandProperties.Setter().withExecutionTimeoutInMilliseconds(2000)), "foo", "bar");
}</code></pre>
</div>
</div>
</div>
</div>
<div class="sect4">
<h5 id="_reactive_example_2"><a class="link" href="#_reactive_example_2">Reactive Example</a></h5>
<div class="exampleblock">
<div class="content">
<div class="listingblock">
<div class="content">
<pre class="highlightjs highlight"><code class="language-java hljs" data-lang="java">@Bean
public Customizer&lt;ReactiveHystrixCircuitBreakerFactory&gt; customizer() {
return factory -&gt; factory.configure(builder -&gt; builder.commandProperties(
HystrixCommandProperties.Setter().withExecutionTimeoutInMilliseconds(2000)), "foo", "bar");
}</code></pre>
</div>
</div>
</div>
</div>
</div>
<strong>1.0.0.BUILD-SNAPSHOT</strong>
</div>
</div>
<div class="sect2">
@@ -360,8 +152,7 @@ public Customizer&lt;ReactiveHystrixCircuitBreakerFactory&gt; customizer() {
<div class="sect3">
<h4 id="_starters"><a class="link" href="#_starters">Starters</a></h4>
<div class="paragraph">
<p>There are two starters for the Resilience4J implementations, one for reactive applications and
one for non-reactive applications.</p>
<p>There are two starters for the Resilience4J implementations, one for reactive applications and one for non-reactive applications.</p>
</div>
<div class="ulist">
<ul>
@@ -375,7 +166,7 @@ one for non-reactive applications.</p>
</div>
</div>
<div class="sect3">
<h4 id="_default_configuration_2"><a class="link" href="#_default_configuration_2">Default Configuration</a></h4>
<h4 id="_default_configuration"><a class="link" href="#_default_configuration">Default Configuration</a></h4>
<div class="paragraph">
<p>To provide a default configuration for all of your circuit breakers create a <code>Customize</code> bean that is passed a
<code>Resilience4JCircuitBreakerFactory</code> or <code>ReactiveResilience4JCircuitBreakerFactory</code>.
@@ -397,7 +188,7 @@ public Customizer&lt;Resilience4JCircuitBreakerFactory&gt; defaultCustomizer() {
</div>
</div>
<div class="sect4">
<h5 id="_reactive_example_3"><a class="link" href="#_reactive_example_3">Reactive Example</a></h5>
<h5 id="_reactive_example"><a class="link" href="#_reactive_example">Reactive Example</a></h5>
<div class="exampleblock">
<div class="content">
<div class="listingblock">
@@ -415,7 +206,7 @@ public Customizer&lt;ReactiveResilience4JCircuitBreakerFactory&gt; defaultCustom
</div>
</div>
<div class="sect3">
<h4 id="_specific_circuit_breaker_configuration_2"><a class="link" href="#_specific_circuit_breaker_configuration_2">Specific Circuit Breaker Configuration</a></h4>
<h4 id="_specific_circuit_breaker_configuration"><a class="link" href="#_specific_circuit_breaker_configuration">Specific Circuit Breaker Configuration</a></h4>
<div class="paragraph">
<p>Similarly to providing a default configuration, you can create a <code>Customize</code> bean this is passed a
<code>Resilience4JCircuitBreakerFactory</code> or <code>ReactiveResilience4JCircuitBreakerFactory</code>.</p>
@@ -434,9 +225,10 @@ public Customizer&lt;Resilience4JCircuitBreakerFactory&gt; slowCustomizer() {
</div>
</div>
<div class="paragraph">
<p>In addition to configuring the circuit breaker that is created you can also customize the circuit breaker after it
has been created but before it is returned to the caller. To do this you can use the <code>addCircuitBreakerCustomizer</code>
method. This can be useful for adding event handlers to Resilience4J circuit breakers.</p>
<p>In addition to configuring the circuit breaker that is created you can also customize the circuit breaker after it has been created but before it is returned to the caller.
To do this you can use the <code>addCircuitBreakerCustomizer</code>
method.
This can be useful for adding event handlers to Resilience4J circuit breakers.</p>
</div>
<div class="exampleblock">
<div class="content">
@@ -452,7 +244,7 @@ public Customizer&lt;Resilience4JCircuitBreakerFactory&gt; slowCustomizer() {
</div>
</div>
<div class="sect4">
<h5 id="_reactive_example_4"><a class="link" href="#_reactive_example_4">Reactive Example</a></h5>
<h5 id="_reactive_example_2"><a class="link" href="#_reactive_example_2">Reactive Example</a></h5>
<div class="exampleblock">
<div class="content">
<div class="listingblock">
@@ -477,7 +269,7 @@ public Customizer&lt;ReactiveResilience4JCircuitBreakerFactory&gt; slowCusomtize
<div class="sect2">
<h3 id="_configuring_sentinel_circuit_breakers"><a class="link" href="#_configuring_sentinel_circuit_breakers">Configuring Sentinel Circuit Breakers</a></h3>
<div class="sect3">
<h4 id="_default_configuration_3"><a class="link" href="#_default_configuration_3">Default Configuration</a></h4>
<h4 id="_default_configuration_2"><a class="link" href="#_default_configuration_2">Default Configuration</a></h4>
<div class="paragraph">
<p>To provide a default configuration for all of your circuit breakers create a <code>Customizer</code> bean that is passed a
<code>SentinelCircuitBreakerFactory</code> or <code>ReactiveSentinelCircuitBreakerFactory</code>.
@@ -502,7 +294,7 @@ You can also choose to load circuit breaking rules later elsewhere using
<code>DegradeRuleManager.loadRules(rules)</code> API of Sentinel, or via Sentinel dashboard.</p>
</div>
<div class="sect4">
<h5 id="_reactive_example_5"><a class="link" href="#_reactive_example_5">Reactive Example</a></h5>
<h5 id="_reactive_example_3"><a class="link" href="#_reactive_example_3">Reactive Example</a></h5>
<div class="exampleblock">
<div class="content">
<div class="listingblock">
@@ -519,7 +311,7 @@ public Customizer&lt;ReactiveSentinelCircuitBreakerFactory&gt; defaultCustomizer
</div>
</div>
<div class="sect3">
<h4 id="_specific_circuit_breaker_configuration_3"><a class="link" href="#_specific_circuit_breaker_configuration_3">Specific Circuit Breaker Configuration</a></h4>
<h4 id="_specific_circuit_breaker_configuration_2"><a class="link" href="#_specific_circuit_breaker_configuration_2">Specific Circuit Breaker Configuration</a></h4>
<div class="paragraph">
<p>Similarly to providing a default configuration, you can create a <code>Customizer</code> bean this is passed a
<code>SentinelCircuitBreakerFactory</code>.</p>
@@ -543,7 +335,7 @@ public Customizer&lt;SentinelCircuitBreakerFactory&gt; slowCustomizer() {
</div>
</div>
<div class="sect4">
<h5 id="_reactive_example_6"><a class="link" href="#_reactive_example_6">Reactive Example</a></h5>
<h5 id="_reactive_example_4"><a class="link" href="#_reactive_example_4">Reactive Example</a></h5>
<div class="exampleblock">
<div class="content">
<div class="listingblock">
@@ -567,17 +359,17 @@ public Customizer&lt;ReactiveSentinelCircuitBreakerFactory&gt; customizer() {
<div class="sect2">
<h3 id="_configuring_spring_retry_circuit_breakers"><a class="link" href="#_configuring_spring_retry_circuit_breakers">Configuring Spring Retry Circuit Breakers</a></h3>
<div class="paragraph">
<p>Spring Retry provides declarative retry support for Spring applications. A subset of the project
includes the ability to implement circuit breaker functionality. Spring Retry provides a circuit breaker
implementation via a combination of it&#8217;s
<p>Spring Retry provides declarative retry support for Spring applications.
A subset of the project includes the ability to implement circuit breaker functionality.
Spring Retry provides a circuit breaker implementation via a combination of it&#8217;s
<a href="https://github.com/spring-projects/spring-retry/blob/master/src/main/java/org/springframework/retry/policy/CircuitBreakerRetryPolicy.java"><code>CircuitBreakerRetryPolicy</code></a>
and a <a href="https://github.com/spring-projects/spring-retry#stateful-retry">stateful retry</a>. All circuit
breakers created using Spring Retry will be created using the <code>CircuitBreakerRetryPolicy</code> and a
and a <a href="https://github.com/spring-projects/spring-retry#stateful-retry">stateful retry</a>.
All circuit breakers created using Spring Retry will be created using the <code>CircuitBreakerRetryPolicy</code> and a
<a href="https://github.com/spring-projects/spring-retry/blob/master/src/main/java/org/springframework/retry/support/DefaultRetryState.java"><code>DefaultRetryState</code></a>.
Both of these classes can be configured using <code>SpringRetryConfigBuilder</code>.</p>
</div>
<div class="sect3">
<h4 id="_default_configuration_4"><a class="link" href="#_default_configuration_4">Default Configuration</a></h4>
<h4 id="_default_configuration_3"><a class="link" href="#_default_configuration_3">Default Configuration</a></h4>
<div class="paragraph">
<p>To provide a default configuration for all of your circuit breakers create a <code>Customize</code> bean that is passed a
<code>SpringRetryCircuitBreakerFactory</code>.
@@ -598,7 +390,7 @@ public Customizer&lt;SpringRetryCircuitBreakerFactory&gt; defaultCustomizer() {
</div>
</div>
<div class="sect3">
<h4 id="_specific_circuit_breaker_configuration_4"><a class="link" href="#_specific_circuit_breaker_configuration_4">Specific Circuit Breaker Configuration</a></h4>
<h4 id="_specific_circuit_breaker_configuration_3"><a class="link" href="#_specific_circuit_breaker_configuration_3">Specific Circuit Breaker Configuration</a></h4>
<div class="paragraph">
<p>Similarly to providing a default configuration, you can create a <code>Customize</code> bean this is passed a
<code>SpringRetryCircuitBreakerFactory</code>.</p>
@@ -616,9 +408,10 @@ public Customizer&lt;SpringRetryCircuitBreakerFactory&gt; slowCustomizer() {
</div>
</div>
<div class="paragraph">
<p>In addition to configuring the circuit breaker that is created you can also customize the circuit breaker after it
has been created but before it is returned to the caller. To do this you can use the <code>addRetryTemplateCustomizers</code>
method. This can be useful for adding event handlers to the <code>RetryTemplate</code>.</p>
<p>In addition to configuring the circuit breaker that is created you can also customize the circuit breaker after it has been created but before it is returned to the caller.
To do this you can use the <code>addRetryTemplateCustomizers</code>
method.
This can be useful for adding event handlers to the <code>RetryTemplate</code>.</p>
</div>
<div class="exampleblock">
<div class="content">
@@ -650,8 +443,6 @@ public Customizer&lt;SpringRetryCircuitBreakerFactory&gt; slowCustomizer() {
</div>
</div>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_building"><a class="link" href="#_building">Building</a></h2>
<div class="sectionbody">