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Merge pull request #188 from fangjian0423/master

Polish #186. Optimize usage of Sentinel RestTemplate
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xiaojing 2018-12-17 22:30:37 +08:00 committed by GitHub
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4 changed files with 171 additions and 25 deletions

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@ -160,9 +160,25 @@ public RestTemplate restTemplate() {
}
```
`@SentinelRestTemplate` 注解的参数跟 `@SentinelResource` 一致,使用方式也一致
`@SentinelRestTemplate` 注解的参数支持限流(`blockHandler`, `blockHandlerClass`)和降级(`fallback`, `fallbackClass`)的处理
限流的资源规则提供两种粒度:
其中 `blockHandler` 或 `fallback` 对应的方法必须是对应 `blockHandlerClass` 或 `fallbackClass` 中的静态方法。
该注解对应的方法参数跟 `ClientHttpRequestInterceptor` 接口中的参数一致,并多出了一个 `BlockException` 参数,且返回值是 `ClientHttpResponse`。
比如上述 `ExceptionUtil` 的 `handleException` 方法对应的声明如下:
```java
public class ExceptionUtil {
public static ClientHttpResponse handleException(HttpRequest request, byte[] body, ClientHttpRequestExecution execution, BlockException exception) {
...
}
}
```
`@SentinelRestTemplate` 注解的限流(`blockHandler`, `blockHandlerClass`)和降级(`fallback`, `fallbackClass`)不强制填写,当被 Sentinel 熔断后,会返回 `RestTemplate request block by sentinel` 信息,或者也可以填写对应的方法自行处理。
Sentinel RestTemplate 限流的资源规则提供两种粒度:
* `schema://host:port/path`:协议、主机、端口和路径
@ -172,7 +188,7 @@ NOTE: 以 `https://www.taobao.com/test` 这个 url 为例。对应的资源名
### 动态数据源支持
#### 在版本 0.2.0.RELEASE 或 0.1.0.RELEASE 之前
#### 在我们的第一个版本 0.2.0.RELEASE 或 0.1.0.RELEASE 中的使用方式
需要3个步骤才可完成数据源的配置
@ -220,7 +236,7 @@ private ReadableDataSource dataSource;
[Sentinel Starter] load 3 flow rules
```
#### 在版本 0.2.0.RELEASE 或 0.1.0.RELEASE 之后
#### 后续版本的使用方式
只需要1个步骤就可完成数据源的配置
@ -253,7 +269,7 @@ NOTE: d1, ds2, ds3, ds4 是 `ReadableDataSource` 的名字,可随意编写。
`data-type` 配置项表示 `Converter`Spring Cloud Alibaba Sentinel 默认提供两种内置的值,分别是 `json` 和 `xml` (不填默认是json)。 如果不想使用内置的 `json` 或 `xml` 这两种 `Converter`,可以填写 `custom` 表示自定义 `Converter`,然后再配置 `converter-class` 配置项,该配置项需要写类的全路径名。
这两种内置的 `Converter` 只支持解析 json 数组 或 xml 数组。内部解析的时候会自动判断每个 json 对象或xml对象属于哪4种 Sentinel 规则(`FlowRule``DegradeRule``SystemRule``AuthorityRule`)。
这两种内置的 `Converter` 只支持解析 json 数组 或 xml 数组。内部解析的时候会自动判断每个 json 对象或xml对象属于哪4种 Sentinel 规则(`FlowRule``DegradeRule``SystemRule``AuthorityRule`, `ParamFlowRule`)。
比如10个规则数组里解析出5个限流规则和5个降级规则。 这种情况下该数据源不会注册,日志里页会进行警告。

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@ -160,9 +160,27 @@ public RestTemplate restTemplate() {
}
```
The parameter of the `@SentinelRestTemplate` annotation and its usage is the same with `@SentinelResource`.
The parameter of the `@SentinelRestTemplate` annotation support flow control(`blockHandler`, `blockHandlerClass`) and circuit breaking(`fallback`, `fallbackClass`).
Sentinel provides two granularities for resource rate limiting:
==
The `blockHandler` or `fallback` is the static method of `blockHandlerClass` or `fallbackClass`.
The parameter of method in `@SentinelRestTemplate` is same as `ClientHttpRequestInterceptor`, but it has one more parameter `BlockException` and its value of return type should be `ClientHttpResponse`.
The method signature of `handleException` in `ExceptionUtil` above should be like this:
```java
public class ExceptionUtil {
public static ClientHttpResponse handleException(HttpRequest request, byte[] body, ClientHttpRequestExecution execution, BlockException exception) {
...
}
}
```
It will return `RestTemplate request block by sentinel` when you do not write any flow control(`blockHandler`, `blockHandlerClass`) configuration or circuit breaking configuration(`fallback`, `fallbackClass`), you can override it by using your own method.
Sentinel RestTemplate provides two granularities for resource rate limiting:
* `schema://host:port/path` Protocol, host, port and path
@ -172,7 +190,7 @@ NOTE: Take `https://www.taobao.com/test` as an example. The corresponding resour
### Dynamic Data Source Support
#### For 0.2.0.RELEASE or 0.1.0.RELEASE and ealier versions,
#### The usage of our first version 0.2.0.RELEASE or 0.1.0.RELEASE
you need to complete the following 3 steps to configure your data source.
@ -220,7 +238,7 @@ If the data source takes effect and is loaded successfully, the dashboard will p
[Sentinel Starter] load 3 flow rules
```
#### In 0.2.0.RELEASE and 0.1.0.RELEASE or later
#### The usage after first version
You only need to complete 1 step to configure your data source:
@ -247,13 +265,13 @@ spring.cloud.sentinel.datasource.ds4.apollo.default-flow-rule-value = test
This method follows the configuration of Spring Cloud Stream Binder. `TreeMap` is used for storage internally, and comparator is `String.CASE_INSENSITIVE_ORDER`.
NOTE: d1, ds2, ds3, ds4 are the names of `ReadableDataSource`, and can be coded as you like. The `file` `zk` `nacos` , `apollo` refer to the specific data sources. The configurations following them are the specific configurations of these data sources respecitively.
NOTE: d1, ds2, ds3, ds4 are the names of `ReadableDataSource`, and can be coded as you like. The `file`, `zk`, `nacos` , `apollo` refer to the specific data sources. The configurations following them are the specific configurations of these data sources respecitively.
Every data source has two common configuration items: `data-type` and `converter-class`.
`data-type` refers to `Converter`. Spring Cloud Alibaba Sentinel provides two embedded values by defaul: `json` and `xml` (the default is json if not specified). If you do not want to use the embedded `json` or `xml` `Converter`, you can also fill in `custom` to indicate that you will define your own `Converter`, and then configure the `converter-class`. You need to specify the full path of the class for this configuration.
The two embedded `Converter` only supports parsing the Json array or XML array. Sentinel will determine automatically which of the 4 Sentinel rules that the Json or XML objext belongs to(`FlowRule``DegradeRule``SystemRule``AuthorityRule`).
The two embedded `Converter` only supports parsing the Json array or XML array. Sentinel will determine automatically which of the 4 Sentinel rules that the Json or XML objext belongs to(`FlowRule`, `DegradeRule`, `SystemRule`, `AuthorityRule`, `ParamFlowRule`).
For example, if 5 rate limiting rules and 5 degradation rules in the 10 rule arrays, then the data source will not be registered, and there will be warnings in the logs.

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@ -19,10 +19,12 @@ package org.springframework.cloud.alibaba.sentinel.custom;
import java.io.IOException;
import java.lang.reflect.Method;
import java.net.URI;
import java.util.Arrays;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.cloud.alibaba.sentinel.annotation.SentinelRestTemplate;
import org.springframework.cloud.alibaba.sentinel.rest.SentinelClientHttpResponse;
import org.springframework.http.HttpRequest;
import org.springframework.http.client.ClientHttpRequestExecution;
import org.springframework.http.client.ClientHttpRequestInterceptor;
@ -60,7 +62,7 @@ public class SentinelProtectInterceptor implements ClientHttpRequestInterceptor
+ (uri.getPort() == -1 ? 80 : uri.getPort());
String hostWithPathResource = hostResource + uri.getPath();
Entry hostEntry = null, hostWithPathEntry = null;
ClientHttpResponse response = null;
ClientHttpResponse response;
try {
ContextUtil.enter(hostWithPathResource);
hostWithPathEntry = SphU.entry(hostWithPathResource);
@ -68,12 +70,15 @@ public class SentinelProtectInterceptor implements ClientHttpRequestInterceptor
response = execution.execute(request, body);
}
catch (BlockException e) {
logger.error("RestTemplate block", e);
try {
handleBlockException(e);
return handleBlockException(request, body, execution, e);
}
catch (Exception ex) {
logger.error("sentinel handle BlockException error.", e);
if (ex instanceof IllegalStateException) {
throw (IllegalStateException) ex;
}
throw new IllegalStateException(
"sentinel handle BlockException error: " + ex.getMessage(), ex);
}
}
finally {
@ -88,14 +93,18 @@ public class SentinelProtectInterceptor implements ClientHttpRequestInterceptor
return response;
}
private void handleBlockException(BlockException ex) throws Exception {
Object[] args = new Object[] { ex };
private ClientHttpResponse handleBlockException(HttpRequest request, byte[] body,
ClientHttpRequestExecution execution, BlockException ex) throws Exception {
Object[] args = new Object[] { request, body, execution, ex };
// handle degrade
if (isDegradeFailure(ex)) {
Method method = extractFallbackMethod(sentinelRestTemplate.fallback(),
sentinelRestTemplate.fallbackClass());
if (method != null) {
method.invoke(null, args);
return (ClientHttpResponse) method.invoke(null, args);
}
else {
return new SentinelClientHttpResponse();
}
}
// handle block
@ -103,7 +112,10 @@ public class SentinelProtectInterceptor implements ClientHttpRequestInterceptor
sentinelRestTemplate.blockHandler(),
sentinelRestTemplate.blockHandlerClass());
if (blockHandler != null) {
blockHandler.invoke(null, args);
return (ClientHttpResponse) blockHandler.invoke(null, args);
}
else {
return new SentinelClientHttpResponse();
}
}
@ -112,10 +124,25 @@ public class SentinelProtectInterceptor implements ClientHttpRequestInterceptor
return null;
}
Method cachedMethod = BlockClassRegistry.lookupFallback(fallbackClass, fallback);
Class[] args = new Class[] { HttpRequest.class, byte[].class,
ClientHttpRequestExecution.class, BlockException.class };
if (cachedMethod == null) {
cachedMethod = ClassUtils.getStaticMethod(fallbackClass, fallback,
BlockException.class);
BlockClassRegistry.updateFallbackFor(fallbackClass, fallback, cachedMethod);
cachedMethod = ClassUtils.getStaticMethod(fallbackClass, fallback, args);
if (cachedMethod != null) {
if (!ClientHttpResponse.class
.isAssignableFrom(cachedMethod.getReturnType())) {
throw new IllegalStateException(String.format(
"the return type of method [%s] in class [%s] is not ClientHttpResponse in degrade",
cachedMethod.getName(), fallbackClass.getCanonicalName()));
}
BlockClassRegistry.updateFallbackFor(fallbackClass, fallback,
cachedMethod);
}
else {
throw new IllegalStateException(String.format(
"Cannot find method [%s] in class [%s] with parameters %s in degrade",
fallback, fallbackClass.getCanonicalName(), Arrays.asList(args)));
}
}
return cachedMethod;
}
@ -125,10 +152,24 @@ public class SentinelProtectInterceptor implements ClientHttpRequestInterceptor
return null;
}
Method cachedMethod = BlockClassRegistry.lookupBlockHandler(blockClass, block);
Class[] args = new Class[] { HttpRequest.class, byte[].class,
ClientHttpRequestExecution.class, BlockException.class };
if (cachedMethod == null) {
cachedMethod = ClassUtils.getStaticMethod(blockClass, block,
BlockException.class);
BlockClassRegistry.updateBlockHandlerFor(blockClass, block, cachedMethod);
cachedMethod = ClassUtils.getStaticMethod(blockClass, block, args);
if (cachedMethod != null) {
if (!ClientHttpResponse.class
.isAssignableFrom(cachedMethod.getReturnType())) {
throw new IllegalStateException(String.format(
"the return type of method [%s] in class [%s] is not ClientHttpResponse in flow control",
cachedMethod.getName(), blockClass.getCanonicalName()));
}
BlockClassRegistry.updateBlockHandlerFor(blockClass, block, cachedMethod);
}
else {
throw new IllegalStateException(String.format(
"Cannot find method [%s] in class [%s] with parameters %s in flow control",
block, blockClass.getCanonicalName(), Arrays.asList(args)));
}
}
return cachedMethod;
}

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@ -0,0 +1,71 @@
/*
* Copyright (C) 2018 the original author or authors.
*
* 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 org.springframework.cloud.alibaba.sentinel.rest;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.springframework.cloud.alibaba.sentinel.annotation.SentinelRestTemplate;
import org.springframework.cloud.alibaba.sentinel.custom.SentinelProtectInterceptor;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.client.AbstractClientHttpResponse;
/**
* Using by {@link SentinelRestTemplate} and {@link SentinelProtectInterceptor}
* @author <a href="mailto:fangjian0423@gmail.com">Jim</a>
*/
public class SentinelClientHttpResponse extends AbstractClientHttpResponse {
private final String BLOCK_STR = "RestTemplate request block by sentinel";
@Override
public int getRawStatusCode() throws IOException {
return HttpStatus.OK.value();
}
@Override
public String getStatusText() throws IOException {
return BLOCK_STR;
}
@Override
public void close() {
// nothing do
}
@Override
public InputStream getBody() throws IOException {
return new ByteArrayInputStream(BLOCK_STR.getBytes());
}
@Override
public HttpHeaders getHeaders() {
Map<String, List<String>> headers = new HashMap<>();
headers.put(HttpHeaders.CONTENT_TYPE,
Arrays.asList(MediaType.APPLICATION_JSON_UTF8_VALUE));
HttpHeaders httpHeaders = new HttpHeaders();
httpHeaders.putAll(headers);
return httpHeaders;
}
}