Spring Boot - 限制创建的连接数

Question

我使用Spring Boot开发了一个微服务.我通过存根后端调用来测试服务的性能.当我查看线程计数时,我发现在任何时间点创建到服务的最大线程数是20,即使调用的数量要高得多.对于可以对使用Spring Boot开发的微服务进行的调用次数是否有任何限制.请您指导我需要遵循哪些步骤来排除故障/增加服务接受的连接数量？

Answer 1

此设置源自嵌入式容器(tomcat,jetty ...).

Tomcat的线程数

您可以在application.properties中指定此属性

server.tomcat.max-threads=400

你说你计算了20个线程,但根据这个其他stackoverflow问题/答案,默认的线程数应该是200与tomcat,因为server.tomcat.max-threads的默认值是0.请参阅tomcat的文档:

此Connector要创建的最大请求处理线程数,因此确定可以处理的最大并发请求数.如果未指定,则此属性设置为200.如果执行程序与此连接器关联,则忽略此属性,因为连接器将使用执行程序而不是内部线程池执行任务.

此外,该财产:

• 承诺:server.undertow.worker-threads

• 码头:server.jetty.acceptors

您可以在Spring的文档中找到属性列表

Answer 2

虽然接受的答案非常有用,但我最近经历了我认为与原始海报相同的问题.这是我能找到的与我的经历直接相关的唯一搜索结果,所以我想我会添加我的解决方案,以防它帮助某人.

在我的情况下,观察到的并发限制为20是由maxConcurrentStreamExecution属性的默认设置20强加的org.apache.coyote.http2.Http2Protocol.

如果你遇到这个问题并且你正在使用HTTP/2,那么增加很有可能maxConcurrentStreamExecution会有所帮助.

您可以在Tomcat配置参考中找到更多信息,它实际上表明默认情况下应该将其设置为200(而不是20).你肯定可以看到20 in的默认设置org.apache.coyote.http2.Http2Protocol,所以我不确定这是一个拼写错误还是只是在嵌入式Tomcat版本中呈现出不同的东西.

Answer 3

也许，您可以看一下springboot的配置

server.tomcat.accept-count=100 # Maximum queue length for incoming connection requests when all possible request processing threads are in use.
server.tomcat.additional-tld-skip-patterns= # Comma-separated list of additional patterns that match jars to ignore for TLD scanning.
server.tomcat.background-processor-delay=10s # Delay between the invocation of backgroundProcess methods. If a duration suffix is not specified, seconds will be used.
server.tomcat.basedir= # Tomcat base directory. If not specified, a temporary directory is used.
server.tomcat.max-connections=10000 # Maximum number of connections that the server accepts and processes at any given time.
server.tomcat.max-http-header-size=0 # Maximum size in bytes of the HTTP message header.
server.tomcat.max-http-post-size=2097152 # Maximum size in bytes of the HTTP post content.
server.tomcat.max-threads=200 # Maximum amount of worker threads.
server.tomcat.min-spare-threads=10 # Minimum amount of worker threads.
server.tomcat.port-header=X-Forwarded-Port # Name of the HTTP header used to override the original port value.
server.tomcat.protocol-header= # Header that holds the incoming protocol, usually named "X-Forwarded-Proto".
server.tomcat.protocol-header-https-value=https # Value of the protocol header indicating whether the incoming request uses SSL.
server.tomcat.redirect-context-root=true # Whether requests to the context root should be redirected by appending a / to the path.
server.tomcat.remote-ip-header= # Name of the HTTP header from which the remote IP is extracted. For instance, `X-FORWARDED-FOR`.
server.tomcat.resource.cache-ttl= # Time-to-live of the static resource cache.
server.tomcat.uri-encoding=UTF-8 # Character encoding to use to decode the URI.
server.tomcat.use-relative-redirects= # Whether HTTP 1.1 and later location headers generated by a call to sendRedirect will use relative or absolute redirects.

Answer 4

如果您有执行器，您可以看到指标

/actuator/metrics/tomcat.threads.config.max

{
  "name": "tomcat.threads.config.max",
  "description": null,
  "baseUnit": null,
  "measurements": [{
    "statistic": "VALUE",
    "value": 200.0
  }],
  "availableTags": [{
    "tag": "name",
    "values": ["http-nio-8080"]
  }]
}

tomcat决定创造的实际价值？/actuator/metrics/tomcat.threads.current

根据负载情况，您可能会看到 10 个

Spring Boot 似乎从来没有完全使用最大线程，但是你可以从更多开始

server:
   tomcat:
     min-spare-threads: 40