v0.99.6

May 28, 2020

🌟 New features

New CircuitBreakerRule and CircuitBreakerRuleWithContent API let you define a complex circuit breaking policy conveniently. #2726

CircuitBreakerRule myRule =
    CircuitBreakerRule.of(
        // A failure if an Exception is raised.
        CircuitBreakerRule.onException(),
        // Neither a success nor a failure because
        // the request has not been handled by the server.
        CircuitBreakerRule.builder()
                          .onUnprocessed()
                          .thenIgnore(),
        // A failure if the response is 5xx.
        CircuitBreakerRule.onServerErrorStatus(),
        // A success if the response is 2xx.
        CircuitBreakerRule.builder()
                          .onStatusClass(HttpStatusClass.SUCCESS)
                          .thenSuccess(),
        // Neither a success nor a failure. Do not take this response into account.
        CircuitBreakerRule.builder().thenIgnore());

You can now easily bind an MDC property to a RequestContext and log it using a logging framework. #2634 #2724 #2729

MDC.put("transactionId", "1234");
WebClient client = ...;
try (SafeCloseable ignored = Clients.withContextCustomizer(ctx -> {
    RequestScopedMdc.copy(ctx, "transactionId");
}) {
    assert MDC.get("transactionId").equals("1234");

    client.execute(...);
}

You can now install a custom hook to RequestContextStorage in runtime, usually at startup time. #2723

RequestContextStorage.hook(delegate -> new RequestContextStorageWrapper(delegate) {
    @Nullable
    @Override
    public <T extends RequestContext> T push(RequestContext toPush) {
        // Usually, you can just use RequestScopedMdc for this purpose.
        MDC.put("foo", toPush.attr(FOO));
        return super.push(toPush);
    }

    @Override
    public void pop(RequestContext current, @Nullable RequestContext toRestore) {
        MDC.remove("foo");
        super.pop(current, toRestore);
    }

    ...
}

You can now set method parameter descriptions for annotated services in DocService using Javadoc. #2697
You can now easily sanitize headers and content using RegexBasedSanitizer. #1810 #2721

📈 Improvements

You can now easily call ownAttr() from RequestContext. #2727
- You don't have to check if the context is ClientRequestContext or not anymore.
- root() and ownAttrs() are pulled up as well.

🛠️ Bug fixes

You can now use Armeria 0.99.6 with Micrometer 1.3.9. (It is recommended to use Micrometer 1.5.1, though.) #2742
You can now retry even when the current EndpointGroup is empty. #2736
You can send a request by setting the authority and scheme header to RequestHeaders. #2730 #2734
You no longer see <zero-length response> in DocService anymore. #2732
A NullPointerException is not raised anymore due to the dependency order when Armeria is shaded. #2731 #2735

☢️ Breaking changes

RetryStrategy and RetryStrategyWithContent are gone in favor of RetryRule and RetryRuleWithContent. #2726
CircuitBreakerStrategy and CircuitBreakerStrategyWithContent are gone in favor of CircuitBreakerRule and CircuitBreakerRuleWithContent. #2726
EndpointSelector.select() (and thus EndpointGroup.select() as well) now returns null instead of throwing an EmptyEndpointGroupException. #2736
The method signature of ClientFactory.acquireEventLoop() and EventLoopScheduler.acquire() have been changed. #2736