Google Git
Sign in
apache / servicecomb-website / 1222c4d5bba2e0b095aea09e6659fcc0da20d5e3 / . / content / references / java-chassis / zh_CN / question-and-answer / question_answer.html
blob: af9fc40ce66c28cfbf6e8836771a5028cb484cb9 [file] [log] [blame]
<!DOCTYPE html>
<html class="writer-html5" lang="en" >
<head>
<meta charset="utf-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<link rel="shortcut icon" href="../img/favicon.ico" />
<title>Q & A - ServiceComb Java Chassis 开发指南</title>
<link rel="stylesheet" href="../css/theme.css" />
<link rel="stylesheet" href="../css/theme_extra.css" />
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/10.5.0/styles/github.min.css" />
<script>
// Current page data
var mkdocs_page_name = "Q \u0026 A";
var mkdocs_page_input_path = "question-and-answer/question_answer.md";
var mkdocs_page_url = null;
</script>
<script src="../js/jquery-3.6.0.min.js" defer></script>
<!--[if lt IE 9]>
<script src="../js/html5shiv.min.js"></script>
<![endif]-->
<script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/10.5.0/highlight.min.js"></script>
<script>hljs.initHighlightingOnLoad();</script>
</head>
<body class="wy-body-for-nav" role="document">
<div class="wy-grid-for-nav">
<nav data-toggle="wy-nav-shift" class="wy-nav-side stickynav">
<div class="wy-side-scroll">
<div class="wy-side-nav-search">
<a href="../index.html" class="icon icon-home"> ServiceComb Java Chassis 开发指南
</a>
</div>
<div class="wy-menu wy-menu-vertical" data-spy="affix" role="navigation" aria-label="Navigation menu">
<ul>
<li class="toctree-l1"><a class="reference internal" href="../toc.html">目录</a>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../index.html">概述</a>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../start/catalog.html">快速入门</a>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../start/design.html">设计选型参考</a>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../build-provider/definition/service-definition.html">微服务定义</a>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../build-provider/catalog.html">开发服务提供者</a>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../build-consumer/catalog.html">开发服务消费者</a>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../general-development/catalog.html">通用功能开发</a>
</li>
</ul>
<p class="caption"><span class="caption-text">多样化的通信协议功能参考</span></p>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../transports/introduction.html">多协议介绍</a>
</li>
<li class="toctree-l1"><a class="reference internal" href="../transports/rest-over-servlet.html">REST over Servlet</a>
</li>
<li class="toctree-l1"><a class="reference internal" href="../transports/rest-over-vertx.html">REST over Vertx</a>
</li>
<li class="toctree-l1"><a class="reference internal" href="../transports/http2.html">REST over HTTP2</a>
</li>
<li class="toctree-l1"><a class="reference internal" href="../transports/highway-rpc.html">Highway</a>
</li>
</ul>
<p class="caption"><span class="caption-text">多样化的服务注册与发现功能参考</span></p>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../registry/introduction.html">注册发现说明</a>
</li>
<li class="toctree-l1"><a class="reference internal" href="../registry/service-center.html">使用服务中心</a>
</li>
<li class="toctree-l1"><a class="reference internal" href="../registry/local-registry.html">本地注册发现</a>
</li>
<li class="toctree-l1"><a class="reference internal" href="../registry/distributed.html">去中心化注册发现</a>
</li>
</ul>
<p class="caption"><span class="caption-text">管理服务配置</span></p>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../config/general-config.html">通用配置说明</a>
</li>
<li class="toctree-l1"><a class="reference internal" href="../config/read-config.html">在程序中读取配置信息</a>
</li>
</ul>
<p class="caption"><span class="caption-text">服务治理功能参考</span></p>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../references-handlers/intruduction.html">处理链介绍</a>
</li>
<li class="toctree-l1"><a class="reference internal" href="../references-handlers/loadbalance.html">负载均衡</a>
</li>
<li class="toctree-l1"><a class="reference internal" href="../references-handlers/ratelimit.html">限流</a>
</li>
<li class="toctree-l1"><a class="reference internal" href="../references-handlers/router.html">灰度发布</a>
</li>
<li class="toctree-l1"><a class="reference internal" href="../references-handlers/fault-injection.html">故障注入</a>
</li>
<li class="toctree-l1"><a class="reference internal" href="../references-handlers/governance.html">流量特征治理</a>
</li>
<li class="toctree-l1"><a class="reference internal" href="../references-handlers/fail-retry.html">快速失败和重试</a>
</li>
</ul>
<p class="caption"><span class="caption-text">网关功能参考</span></p>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../edge/open-service.html">介绍</a>
</li>
<li class="toctree-l1"><a class="reference internal" href="../edge/by-servicecomb-sdk.html">使用 Edge Service 做网关</a>
</li>
<li class="toctree-l1"><a class="reference internal" href="../edge/zuul.html">使用 `zuul` 和 `spring cloud gateway` 做网关</a>
</li>
<li class="toctree-l1"><a class="reference internal" href="../edge/nginx.html">nginx 网关简单介绍</a>
</li>
</ul>
<p class="caption"><span class="caption-text">安全特性参考</span></p>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../references-handlers/publickey.html">公钥认证</a>
</li>
<li class="toctree-l1"><a class="reference internal" href="../security/tls.html">使用TLS通信</a>
</li>
<li class="toctree-l1"><a class="reference internal" href="../security/shi-yong-rsa-ren-zheng.html">使用RSA认证</a>
</li>
</ul>
<p class="caption"><span class="caption-text">服务打包和运行</span></p>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../packaging/standalone.html">以standalone模式打包</a>
</li>
<li class="toctree-l1"><a class="reference internal" href="../packaging/web-container.html">以WEB容器模式打包</a>
</li>
</ul>
<p class="caption"><span class="caption-text">专题文章</span></p>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../using-java-chassis-in-spring-boot/using-java-chassis-in-spring-boot.html">在Spring Boot中使用java chassis</a>
</li>
<li class="toctree-l1"><a class="reference internal" href="../featured-topics/features.html">新功能介绍系列文章</a>
</li>
<li class="toctree-l1"><a class="reference internal" href="../featured-topics/compatibility.html">兼容问题和兼容性策略</a>
</li>
<li class="toctree-l1"><a class="reference internal" href="../featured-topics/upgrading.html">升级指导系列文章</a>
</li>
<li class="toctree-l1"><a class="reference internal" href="../featured-topics/performance.html">性能问题分析和调优</a>
</li>
</ul>
<p class="caption"><span class="caption-text">常用配置项参考</span></p>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../config-reference/rest-transport-client.html">REST Transport Client 配置项</a>
</li>
<li class="toctree-l1"><a class="reference internal" href="../config-reference/config-center-client.html">Config Center Client 配置项</a>
</li>
<li class="toctree-l1"><a class="reference internal" href="../config-reference/service-center-client.html">Service Center Client 配置项</a>
</li>
<li class="toctree-l1"><a class="reference internal" href="../config-reference/kie-client.html">ServiceComb Kie Client 配置项</a>
</li>
</ul>
<p class="caption"><span class="caption-text">常见问题</span></p>
<ul class="current">
<li class="toctree-l1"><a class="reference internal" href="faq.html">FAQ</a>
</li>
<li class="toctree-l1 current"><a class="reference internal current" href="question_answer.html">Q & A</a>
<ul class="current">
</ul>
</li>
<li class="toctree-l1"><a class="reference internal" href="interface-compatibility.html">微服务接口兼容常见问题</a>
</li>
</ul>
</div>
</div>
</nav>
<section data-toggle="wy-nav-shift" class="wy-nav-content-wrap">
<nav class="wy-nav-top" role="navigation" aria-label="Mobile navigation menu">
<i data-toggle="wy-nav-top" class="fa fa-bars"></i>
<a href="../index.html">ServiceComb Java Chassis 开发指南</a>
</nav>
<div class="wy-nav-content">
<div class="rst-content"><div role="navigation" aria-label="breadcrumbs navigation">
<ul class="wy-breadcrumbs">
<li><a href="../index.html" class="icon icon-home" alt="Docs"></a> &raquo;</li>
<li>常见问题 &raquo;</li>
<li>Q & A</li>
<li class="wy-breadcrumbs-aside">
</li>
</ul>
<hr/>
</div>
<div role="main" class="document" itemscope="itemscope" itemtype="http://schema.org/Article">
<div class="section" itemprop="articleBody">
<h1 id="javaresthttp-status-code">问题描述：如何自定义某个Java方法对应的REST接口里的HTTP Status Code？</h1>
<p><strong> 解决方法：</strong></p>
<p>对于正常的返回值，可以通过SwaggerAnnotation实现，例如：</p>
<pre><code class="language-java">@ApiResponse(code = 300, response = String.class, message = &quot;&quot;)
public int test(int x) {
return 100;
}
</code></pre>
<p>对于异常的返回值，可以通过抛出自定义的InvocationException实现，例如：、</p>
<pre><code class="language-java"> public String testException(int code) {
String strCode = String.valueOf(code);
switch (code) {
case 200:
return strCode;
case 456:
throw new InvocationException(code, strCode, strCode + &quot; error&quot;);
case 556:
throw new InvocationException(code, strCode, Arrays.asList(strCode + &quot; error&quot;));
case 557:
throw new InvocationException(code, strCode, Arrays.asList(Arrays.asList(strCode + &quot; error&quot;)));
default:
break;
}
return &quot;not expected&quot;;
}
</code></pre>
<h1 id="_1">问题描述： 如何定制自己微服务的日志配置</h1>
<p><strong> 解决方法：</strong><br />
ServiceComb不绑定日志器，只是使用了slf4j，用户可以自由选择log4j/log4j2/logback等等。ServiceComb提供了一个log4j的扩展，在标准log4j的基础上，支持log4j的properties文件的增量配置。</p>
<ul>
<li>默认以规则："classpath*:config/log4j.properties"加载配置文件</li>
<li>实际会搜索出classpath中所有的<code>config/log4j.properties和config/log4j.*.properties</code>, 从搜索出的文件中切出<code>\*</code>的部分，进行alpha排序，然后按顺序加载，最后合成的文件作为log4j的配置文件。</li>
<li>如果要使用ServiceComb的log4j扩展，则需要调用Log4jUtils.init，否则完全按标准的日志器的规则使用。</li>
</ul>
<h1 id="transporttransport">问题描述： 当服务配置了多个transport的时候，在运行时是怎么选择使用哪个transport的？</h1>
<p><strong> 解决方法：</strong></p>
<ul>
<li>
<p>ServiceComb的consumer、transport、handler、producer之间是解耦的，各功能之间通过契约定义联合在一起工作的，即：<br />
consumer使用透明rpc，还是springmvc开发与使用highway，还是RESTful在网络上传输没有关系与producer是使用透明rpc，还是jaxrs，或者是springmvc开发，也没有关系handler也不感知，业务开发方式以及传输方式</p>
</li>
<li>
<p>consumer访问producer，在运行时的transport选择上，总规则为：<br />
consumer的transport与producer的endpoint取交集，如果交集后，还有多个transport可选择，则轮流使用</p>
</li>
</ul>
<p>分解开来，存在以下场景：</p>
<ul>
<li>当一个微服务producer同时开放了highway以及RESTful的endpoint</li>
<li>consumer进程中只部署了highway transport jar，则只会访问producer的highway endpoint</li>
<li>consumer进程中只部署了RESTful transport jar，则只会访问producer的RESTful endpoint</li>
<li>consumer进程中，同时部署了highway和RESTful transport jar，则会轮流访问producer的highway、RESTful endpoint</li>
</ul>
<p>如果，此时consumer想固定使用某个transport访问producer，可以在consumer进程的microservice.yaml中配置，指定transport的名称:</p>
<pre><code>servicecomb:
references:
transport:
&lt;service_name&gt;: highway
</code></pre>
<ul>
<li>
<p>当一个微服务producer只开放了highway的endpoint</p>
</li>
<li>
<p>consumer进程只部署了highway transport jar，则正常使用higway访问</p>
</li>
<li>consumer进程只部署了RESTful transport jar，则无法访问</li>
<li>
<p>consumer进程同时部署了highway和RESTful transport jar，则正常使用highway访问</p>
</li>
<li>
<p>当一个微服务producer只开放了RESTful的endpoint</p>
</li>
<li>
<p>consumer进程只部署了highway transport jar，则无法访问</p>
</li>
<li>consumer进程只部署了RESTful transport jar，则正常使用RESTful访问</li>
<li>consumer进程同时部署了highway和RESTful transport jar，则正常使用RESTful访问</li>
</ul>
<h1 id="swagger-body">问题描述： swagger body参数类型定义错误，导致服务中心注册的内容没有类型信息</h1>
<p><strong>现象描述:</strong></p>
<p>定义如下接口，将参数放到body传递</p>
<pre><code>/testInherate:
post:
operationId: &quot;testInherate&quot;
parameters:
- in: &quot;body&quot;
name: &quot;xxxxx&quot;
required: false
type: string
responses:
200:
description: &quot;response of 200&quot;
schema:
$ref: &quot;#/definitions/ReponseImpl&quot;
</code></pre>
<p>采用上面方式定义接口。在服务注册以后，从服务中心查询下来的接口type: string 丢失，变成了：</p>
<pre><code>/testInherate:
post:
operationId: &quot;testInherate&quot;
parameters:
- in: &quot;body&quot;
name: &quot;xxxxx&quot;
required: false
responses:
200:
description: &quot;response of 200&quot;
schema:
$ref: &quot;#/definitions/ReponseImpl&quot;
</code></pre>
<p>如果客户端没有放置swagger，还会报告如下异常：</p>
<p>Caused by: java.lang.ClassFormatError: Method "testInherate" in class ? has illegal signature "</p>
<p><strong>解决方法：</strong></p>
<p>定义body参数的类型的时候，需要使用schema，不能直接使用type。</p>
<pre><code>/testInherate:
post:
operationId: &quot;testInherate&quot;
parameters:
- in: &quot;body&quot;
name: &quot;request&quot;
required: false
schema:
type: string
responses:
200:
description: &quot;response of 200&quot;
schema:
$ref: &quot;#/definitions/ReponseImpl&quot;
</code></pre>
<h1 id="_2">问题描述：微服务框架服务调用是否使用长连接</h1>
<p><strong> 解决方法：</strong></p>
<p>http使用的是长连接（有超时时间），highway方式使用的是长连接（一直保持）。</p>
<h1 id="_3">问题描述：服务断连服务中心注册信息是否自动删除</h1>
<p><strong> 解决方法：</strong></p>
<p>服务中心心跳检测到服务实例不可用，只会移除服务实例信息，服务的静态数据不会移除。</p>
<h1 id="_4">问题描述：微服务框架如何实现数据多个微服务间透传</h1>
<p><strong> 解决方法：</strong></p>
<p>透传数据塞入：</p>
<pre><code class="language-java">CseHttpEntity&lt;xxxx.class&gt; httpEntity = new CseHttpEntity&lt;&gt;(xxx);
//透传内容
httpEntity.addContext(&quot;contextKey&quot;,&quot;contextValue&quot;);
ResponseEntity&lt;String&gt; responseEntity = RestTemplateBuilder.create().exchange(&quot;cse://springmvc/springmvchello/sayhello&quot;,HttpMethod.POST,httpEntity,String.class);
</code></pre>
<p>透传数据获取：</p>
<pre><code class="language-java">@Override
@RequestMapping(path=&quot;/sayhello&quot;,method = RequestMethod.POST)
public String sayHello(@RequestBody Person person,InvocationContext context){
//透传数据获取
context.getContext();
return &quot;Hello person &quot; + person.getName();
}
</code></pre>
<h1 id="_5">问题描述：微服务框架服务如何自定义返回状态码</h1>
<p><strong> 解决方法：</strong></p>
<pre><code class="language-java">@Override
@RequestMapping(path = &quot;/sayhello&quot;,method = RequestMethod.POST)
public String sayHello(@RequestBody Person person){
InvocationContext context = ContextUtils.getInvocationContext();
//自定义状态码
context.setStatus(Status.CREATED);
return &quot;Hello person &quot;+person.getName();
}
</code></pre>
<h1 id="body-model">问题描述： body Model部分暴露</h1>
<p><strong> 解决方法：</strong></p>
<p>一个接口对应的body对象中，可能有一些属性是内部的，不想开放出去，生成schema的时候不要带出去，使用：</p>
<pre><code class="language-java">@ApiModelProperty(hidden = true)
</code></pre>
<h1 id="consumer">问题描述：框架获取远端consumer的地址</h1>
<p><strong> 解决方法：</strong></p>
<p>如果使用http rest方式（使用transport-rest-vertx依赖）可以用下面这种方式获取：</p>
<pre><code class="language-java">HttpServletRequest request = (HttpServletRequest) invocation.getHandlerContext().get(RestConst.REST_REQUEST);
String host = request.getRemoteHost();
</code></pre>
<p>实际场景是拿最外层的地址，所以应该是LB传入到edgeservice，edgeService再放到context外下传递。</p>
<h1 id="handler">问题描述：对handler描述</h1>
<p><strong> 解决方法：</strong></p>
<p>consumer默认的handler是simpleLB，没有配置的时候handler链会使用这个，如果配置了handler，里面一定要包含lb的handler，否则调用报错，需要在文档里面进行说明。</p>
<h1 id="netty">问题描述：netty版本问题</h1>
<p><strong> 解决方法：</strong></p>
<p>netty3和netty4是完全不同的三方件，因为坐标跟package都不相同，所以可以共存，但是要注意小版本问题，小版本必须使用的版本。</p>
<h1 id="_6">问题描述：服务超时设置</h1>
<p><strong> 解决方法：</strong></p>
<p>在微服务描述文件（microservice.yaml）中添加如下配置：</p>
<pre><code>servicecomb:
request:
timeout: 30000
</code></pre>
<h1 id="_7">问题描述：服务治理的处理链顺序是否有要求？</h1>
<p><strong>解决方法：</strong></p>
<p>处理链的顺序不同，那么系统工作行为也不同。 下面列举一下常见问题。</p>
<p>1、loadbalance和bizkeeper-consumer</p>
<p>这两个顺序可以随机组合。但是行为是不一样的。</p>
<p>当loadbalance在前面的时候，那么loadbalance提供的重试功能会在bizkeeper-consumer抛出异常时发生，比如超时等。但是如果已经做了fallbackpolicy配置，比如returnnull，那么loadbalance则不会重试。</p>
<p>如果loadbalance在后面，那么loadbalance的重试会延长超时时间，即使重试成功，如果bizkeeper-consumer设置的超时时间不够，那么最终的调用结果也是失败。</p>
<p>2、tracing-consumer，sla-consumer，tracing-provider，sla-provider</p>
<p>这些处理链建议放到处理链的最开始位置，保证成功、失败的情况都可以记录日志（由于记录日志需要IP等信息，对于消费者，只能放到loadbalance后面）。</p>
<p>如果不需要记录客户端返回的异常，则可以放到末尾，只关注网络层返回的错误。但是如果bizkeeper-consumer等超时提前返回的话，则可能不会记录日志。</p>
<p>3、建议的顺序</p>
<p>Consumer: loadbalance, tracing-consumer, sla-consumer, bizkeeper-consumer</p>
<p>Provider: tracing-provider, sla-provider, bizkeeper-provider</p>
<p>这种顺序能够满足大多数场景，并且不容易出现不可理解的错误。</p>
<h1 id="_8">问题描述： 文件上传中配置项最大请求大小的含义</h1>
<p>配置项： servicecomb.uploads.maxSize</p>
<p>含义： 请求体中允许的最大字节数，默认值为-1，表示没有限制。</p>
</div>
</div><footer>
<div class="rst-footer-buttons" role="navigation" aria-label="Footer Navigation">
<a href="faq.html" class="btn btn-neutral float-left" title="FAQ"><span class="icon icon-circle-arrow-left"></span> Previous</a>
<a href="interface-compatibility.html" class="btn btn-neutral float-right" title="微服务接口兼容常见问题">Next <span class="icon icon-circle-arrow-right"></span></a>
</div>
<hr/>
<div role="contentinfo">
<!-- Copyright etc -->
</div>
Built with <a href="https://www.mkdocs.org/">MkDocs</a> using a <a href="https://github.com/readthedocs/sphinx_rtd_theme">theme</a> provided by <a href="https://readthedocs.org">Read the Docs</a>.
</footer>
</div>
</div>
</section>
</div>
<div class="rst-versions" role="note" aria-label="Versions">
<span class="rst-current-version" data-toggle="rst-current-version">
<span><a href="faq.html" style="color: #fcfcfc">&laquo; Previous</a></span>
<span><a href="interface-compatibility.html" style="color: #fcfcfc">Next &raquo;</a></span>
</span>
</div>
<script>var base_url = '..';</script>
<script src="../js/theme_extra.js" defer></script>
<script src="../js/theme.js" defer></script>
<script src="../search/main.js" defer></script>
<script defer>
window.onload = function () {
SphinxRtdTheme.Navigation.enable(true);
};
</script>
</body>
</html>