升级Elastic至8.16后Spring Boot Micrometer间歇性上报指标失败：Premature EOF

问题概述 #

使用Spring Boot 3.3.6（依赖micrometer-elastic-registry 1.13.6），将Elasticsearch从8.11.4升级至8.16后，出现间歇性指标上报失败的Premature EOF错误，此前无此问题，未修改其他配置，错误出现频率较低，未找到官方明确的版本不兼容信息。

错误堆栈如下：

java.io.UncheckedIOException: java.io.IOException: Premature EOF
    at io.micrometer.core.instrument.util.IOUtils.toString(IOUtils.java:55)
    at io.micrometer.core.instrument.util.IOUtils.toString(IOUtils.java:65)
    at io.micrometer.core.ipc.http.HttpUrlConnectionSender.send(HttpUrlConnectionSender.java:112)
    at io.micrometer.core.ipc.http.HttpSender$Request$Builder.send(HttpSender.java:306)
    at io.micrometer.elastic.ElasticMeterRegistry.publish(ElasticMeterRegistry.java:129)
    at io.micrometer.core.instrument.push.PushMeterRegistry.publishSafelyOrSkipIfInProgress(PushMeterRegistry.java:64)
    at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
    at java.base/java.util.concurrent.FutureTask.runAndReset(Unknown Source)
    at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(Unknown Source)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.base/java.lang.Thread.run(Unknown Source)
Caused by: java.io.IOException: Premature EOF
    at java.base/sun.net.www.http.ChunkedInputStream.fastRead(Unknown Source)
    at java.base/sun.net.www.http.ChunkedInputStream.read(Unknown Source)
    at java.base/java.io.FilterInputStream.read(Unknown Source)
    at java.base/sun.net.www.protocol.http.HttpURLConnection$HttpInputStream.read(Unknown Source)
    at java.base/sun.nio.cs.StreamDecoder.readBytes(Unknown Source)
    at java.base/sun.nio.cs.StreamDecoder.implRead(Unknown Source)
    at java.base/sun.nio.cs.StreamDecoder.lockedRead(Unknown Source)
    at java.base/sun.nio.cs.StreamDecoder.read(Unknown Source)
    at java.base/java.io.InputStreamReader.read(Unknown Source)
    at java.base/java.io.BufferedReader.fill(Unknown Source)
    at java.base/java.io.BufferedReader.read1(Unknown Source)
    at java.base/java.io.BufferedReader.implRead(Unknown Source)
    at java.base/java.io.BufferedReader.read(Unknown Source)
    at java.base/java.io.Reader.read(Unknown Source)
    at io.micrometer.core.instrument.util.IOUtils.toString(IOUtils.java:49)
    ... 11 more

可能的解决方案 #

• 升级Micrometer Elastic Registry版本：当前1.13.6版本可能未适配Elasticsearch 8.16的HTTP协议细节，尝试升级到与Spring Boot 3.3.6兼容的最新Micrometer版本（如1.13.x系列最新版，或Spring Boot依赖管理推荐的版本），新版本通常会修复与高版本Elasticsearch的通信问题。
• 更换HTTP客户端实现：默认的HttpUrlConnectionSender可能存在与Elasticsearch 8.16分块响应处理的兼容性问题，尝试切换到OkHttp或Apache HttpClient作为Micrometer的HTTP发送器。例如添加OkHttp依赖后，配置elastic.metrics.export.http-client=okhttp。
• 调整连接超时与重试策略：增加连接、读取超时时间，并配置重试机制，应对间歇性的网络或服务端响应中断。可通过以下配置调整：

  management.metrics.export.elastic.connect-timeout=10s
  management.metrics.export.elastic.read-timeout=10s
  management.metrics.export.elastic.num-threads=2
  management.metrics.export.elastic.retries=3
  

• 检查Elasticsearch服务端日志：查看Elasticsearch 8.16的服务端日志，确认是否存在请求处理异常、连接中断等情况，排查是否是服务端主动关闭连接导致的EOF。
• 临时禁用HTTP分块编码：尝试在Micrometer的HTTP请求中禁用分块编码，测试是否能规避问题。可通过自定义HttpUrlConnectionSender修改请求配置，关闭分块模式。

内容的提问来源于stack exchange，提问作者Xli