org.openqa.selenium.WebDriverException：会话[null]不可用，也不是在Docker中使用SeleniumGrid的最近1000个终止会话中的会话

Question

我正在运行硒网格，并且有2个节点连接到它。但是，当我尝试运行测试脚本（.java）时，出现错误：

Exception in thread "Thread-23" org.openqa.selenium.WebDriverException: Session [null] not available and is not among the last 1000 terminated sessions.
Active sessions are[ext. key 3e5f8fb2ae3b0c5cddc8817f80eb8fe1]
Command duration or timeout: 92 milliseconds
Build info: version: 'unknown', revision: 'unknown', time: 'unknown'

在VNC客户端中，Chrome浏览器打开，但是未加载URL并引发了错误。

注意：该脚本是使用maven从另一个Docker容器运行的。

当我将脚本作为Java应用程序运行时，它可以正常工作，但是在docker中，我收到了错误消息。**

Answer 1

此错误消息...

Exception in thread "Thread-23" org.openqa.selenium.WebDriverException: Session [null] not available and is not among the last 1000 terminated sessions.
Active sessions are[ext. key 3e5f8fb2ae3b0c5cddc8817f80eb8fe1]
Command duration or timeout: 92 milliseconds
Build info: version: 'unknown', revision: 'unknown', time: 'unknown'

...表示Selenium Grid Node无法与Selenium Grid Hub通信。

---

深潜

此错误在ActiveTestSessions.java中定义，并定义为：

public TestSession getExistingSession(ExternalSessionKey externalkey) {
    TestSession sessionByExternalKey = findSessionByExternalKey(externalkey);
    if (sessionByExternalKey == null) {
      SessionTerminationReason sessionTerminationReason = reasons.get(externalkey);
      String keyId = externalkey != null ? externalkey.getKey() : "(null externalkey)";
      if (sessionTerminationReason != null) {
          String msg = "Session [" + keyId + "] was terminated due to " + sessionTerminationReason;
          log.fine(msg);
          throw new GridException(msg);
      } else {
          String msg = "Session [" + keyId + "] not available and is not among the last 1000 terminated sessions.\n"
          + "Active sessions are" + this.unmodifiableSet();
          log.fine(msg);
          throw new GridException(msg);
      }
    }
    return sessionByExternalKey;
}

根据以下讨论：

• Session [....] not available and is not among the last 1000 terminated sessions
• Selenium 3.9.0 & above gives error "Session [null] not available and is not among the last 1000 terminated sessions." on geckodriver

看来此错误源于以下时间：

• Selenium Grid Hub，Selenium Grid Node和Client Process是从Selenium客户端的不同版本启动/产生的。

---

解决方案

确保Selenium Grid Hub，Selenium Grid Node和Client Process都使用相同版本的Selenium客户端，即Selenium v​​3.141.59

---

更新

[在正常情况下，如果同一罐子存在多个版本，则应该观察到Selenium Webdriver + Java - Eclipse: java.lang.NoClassDefFoundError。您的Test Architecture的更多细节将帮助我们以更好的方式调试问题。可能您需要按以下方式清理：

• mvn clean
• mvn install
• 或mvn clean install
• mvn test