我有一个通过REST调用依赖项的服务。服务和依赖关系是微服务体系结构的一部分，因此我想使用弹性模式。我的目标是：
下面是我当前的代码。它可以工作，但是理想情况下，我想使用TimeLimiter和Bulkhead类，因为它们似乎是可以一起工作的。
我该如何写得更好？
@Component
class FooService(@Autowired val circuitBreakerRegistry: CircuitBreakerRegistry)
{
...
// State machine to take load off the dependency when slow or unresponsive
private val circuitBreaker = circuitBreakerRegistry
.circuitBreaker("fooService")
// Limit parallel requests to dependency
private var semaphore = Semaphore(maxParallelRequests)
// The protected function
private suspend fun makeHttpCall(customerId: String): Boolean {
val client = webClientProvider.getCachedWebClient(baseUrl)
val response = client
.head()
.uri("/the/request/url")
.awaitExchange()
return when (val status = response.rawStatusCode()) {
200 -> true
204 -> false
else -> throw Exception(
"Foo service responded with invalid status code: $status"
)
}
}
// Main function
suspend fun isFoo(someId: String): Boolean {
try {
return circuitBreaker.executeSuspendFunction {
semaphore.withPermit {
try {
withTimeout(timeoutMs) {
makeHttpCall(someId)
}
} catch (e: TimeoutCancellationException) {
// This exception has to be converted because
// the circuit-breaker ignores CancellationException
throw Exception("Call to foo service timed out")
}
}
}
} catch (e: CallNotPermittedException) {
logger.error { "Call to foo blocked by circuit breaker" }
} catch (e: Exception) {
logger.error { "Exception while calling foo service: ${e.message}" }
}
// Fallback
return true
}
}
理想情况下，我想编写类似于docs的Flow描述：
// Main function
suspend fun isFoo(someId: String): Boolean {
return monoOf(makeHttpCall(someId))
.bulkhead(bulkhead)
.timeLimiter(timeLimiter)
.circuitBreaker(circuitBreaker)
}
答案 0 :(得分：0)
您也可以使用Resilience4j的隔板来代替自己的信号量和Resilience4j的TimeLimiter。
您可以使用.select2-container {
min-width: 100%;
}
.select2-results__option {
padding-right: 20px;
vertical-align: middle;
}
.select2-results__option:before {
content: "";
display: inline-block;
position: relative;
height: 20px;
width: 20px;
border: 2px solid #e9e9e9;
background-color: #fff;
margin-right: 20px;
vertical-align: middle;
}
.select2-container--default .select2-selection--multiple {
background-color: #FFFFFF;
border: 1px solid #CBD5DD;
border-radius: 2px;
cursor: text;
height: auto !important;
margin: 0;
min-height: 30px;
overflow: hidden;
padding: 2px;
position: relative;
width: 100%;
}
.select2-results__option[aria-selected=true] {
display: none;
}
.select2-container--default .select2-results__option[aria-selected=true] {
background-color: #fff;
}
.select2-container--default .select2-results__option--highlighted[aria-selected] {
background-color: #3875d7;
background-image: -webkit-gradient(linear, 50% 0%, 50% 100%, color-stop(20%, #3875d7), color-stop(90%, #2a62bc));
background-image: -webkit-linear-gradient(#3875d7 20%, #2a62bc 90%);
background-image: -moz-linear-gradient(#3875d7 20%, #2a62bc 90%);
background-image: -o-linear-gradient(#3875d7 20%, #2a62bc 90%);
background-image: linear-gradient(#3875d7 20%, #2a62bc 90%);
color: #fff;
}
.select2-container--default .select2-selection--multiple {
margin-bottom: 10px;
}
.select2-container--default.select2-container--open.select2-container--below .select2-selection--multiple {
border-radius: 4px;
}
.select2-container--default.select2-container--focus .select2-selection--multiple {
border: 1px solid #5897fb;
box-shadow: 0 0 5px rgba(0, 0, 0, 0.3);
}
.select2-container--default .select2-selection--multiple {
border-width: 1px;
}
.select2-container--open .select2-dropdown--below {
border-radius: 6px;
box-shadow: 0 0 10px rgba(0,0,0,0.5);
}
.select2-selection .select2-selection--multiple:after {
content: 'hhghgh';
}
/* select with icons badges single*/
.select-icon .select2-selection__placeholder .badge {
display: none;
}
.select-icon .placeholder {
display: none;
}
.select-icon .select2-results__option:before,
.select-icon .select2-results__option[aria-selected=true]:before {
display: none !important;
/* content: "" !important; */
}
.select-icon .select2-search--dropdown {
display: none;
}
.select2-container--default .select2-selection--multiple .select2-selection__choice {
position: relative;
margin: 3px 0 3px 5px;
padding: 3px 3px 3px 5px;
border: 1px solid #aaa;
border-radius: 3px;
background-color: #e4e4e4;
background-image: -webkit-gradient(linear, 50% 0%, 50% 100%, color-stop(20%, #f4f4f4), color-stop(50%, #f0f0f0), color-stop(52%, #e8e8e8), color-stop(100%, #eeeeee));
background-image: -webkit-linear-gradient(#f4f4f4 20%, #f0f0f0 50%, #e8e8e8 52%, #eeeeee 100%);
background-image: -moz-linear-gradient(#f4f4f4 20%, #f0f0f0 50%, #e8e8e8 52%, #eeeeee 100%);
background-image: -o-linear-gradient(#f4f4f4 20%, #f0f0f0 50%, #e8e8e8 52%, #eeeeee 100%);
background-image: linear-gradient(#f4f4f4 20%, #f0f0f0 50%, #e8e8e8 52%, #eeeeee 100%);
background-clip: padding-box;
box-shadow: 0 0 2px white inset, 0 1px 0 rgba(0, 0, 0, 0.05);
color: #333;
line-height: 13px;
cursor: default;
}
.select2-container--default .select2-selection--multiple .select2-selection__rendered li {
list-style: none;
width: auto !important;
}
.select2-remove-right {
float: right;
}
.select2-container--default .select2-selection--multiple .select2-selection__choice__remove {
float: right;
margin-left: 5px;
}
ul.select2-choices {
padding-right: 30px !important;
}
ul.select2-choices:after {
content: "";
position: absolute;
right: 10px;
top: 50%;
transform: translateY(-50%);
border-top: 5px solid #333;
border-left: 5px solid transparent;
border-right: 5px solid transparent;
}
.select2-container--default .select2-search--inline .select2-search__field{
width:initial!important;
}
.select2-dropdown {
border-radius: 0px;
background-color: white;
border: 1px solid #DDD;
box-sizing: border-box;
display: block;
position: absolute;
left: -100000px;
width: 100%;
z-index: 1051;
}
/* line 43, ../scss/_dropdown.scss */
.select2-container--open .select2-dropdown--above {
border-bottom: none;
border-bottom-left-radius: 0;
border-bottom-right-radius: 0;
}
.select2-container--open .select2-dropdown--below {
border-top: none;
border-top-left-radius: 0;
border-top-right-radius: 0;
}
.select2-container--open .select2-dropdown {
left: 0;
}
.select2-search--dropdown {
display: block;
padding: 7px;
}
.select2-search--dropdown .select2-search__field {
padding: 4px;
width: 100%;
box-sizing: border-box;
}
.select2-search--dropdown .select2-search__field::-webkit-search-cancel-button {
-webkit-appearance: none;
}
.select2-search--dropdown.select2-search--hide {
display: none;
}
和bulkhead.executeSuspendFunction将CircuitBreaker堆叠起来。