Question

我的测试堆栈包含最新版本的Selenium Server（2.33.0，又名selenium-server-standalone-2.33.0.jar），Mocha，Node.js和PhantomJS。

我的问题涉及以下代码：

var webdriver = require('../../../lib/selenium/node_modules/selenium-webdriver/'),
        driver = new webdriver.Builder().
            withCapabilities({'browserName': 'phantomjs'}).
            build();

driver.manage().timeouts().implicitlyWait(15000);

describe('Wordpress', function() {
    it('should be able to log in', function(done) {
        driver.get('http://#### REDACTED ####/wp-login.php');
        driver.findElement(webdriver.By.css('#user_login')).sendKeys('#### REDACTED ####');
        driver.findElement(webdriver.By.css('#user_pass')).sendKeys('#### REDACTED ####');
        driver.findElement(webdriver.By.css('#wp-submit')).click();

        // #wpwrap is an element on the Wordpress dashboard that is displayed once
        // the user is logged in.  By testing for its presence, we can determine
        // if the login attempt succeeded.
        driver.findElement(webdriver.By.css('#wpwrap')).then(function(v) {
            done();
        });
    });
});

在我的本地系统OS X上，测试运行良好。但是，一旦测试上传到我们的CentOS服务器（我们希望进行持续集成测试），测试表现得非常奇怪。

启动Selenium Server后，测试成功运行一次。从那时起，测试仅在十次左右的时间内成功。重新启动Selenium Server可确保测试成功运行。实际上，如果每次运行测试时重新启动Selenium Server，则每次测试都会成功。

如何在不重新启动Selenium Server的情况下成功完成此测试？

非常感谢你的帮助！：）

更新：除了下面的错误日志，我偶尔也会收到以下错误：线程“Thread-21”中的异常java.lang.OutOfMemoryError：无法创建新的本机线程

有关错误消息的详细信息如下：

成功测试从Mocha产生以下输出：

[s5rich@host ~]$ mocha test/selenium/acceptance/simple.js


  Wordpress
    ✓ should be able to log in (2604ms)


  1 passing (3 seconds)

成功测试还会从Selenium Server获得以下输出：

23:21:50.517 INFO - Executing: [new session: {browserName=phantomjs}] at URL: /session)
23:21:50.527 INFO - Creating a new session for Capabilities [{browserName=phantomjs}]
23:21:50.547 INFO - executable: /usr/local/bin/phantomjs
23:21:50.547 INFO - port: 26515
23:21:50.547 INFO - arguments: [--webdriver=26515, --webdriver-logfile=/home/s5rich/phantomjsdriver.log]
23:21:50.547 INFO - environment: {}
PhantomJS is launching GhostDriver...
[INFO  - 2013-07-24T05:21:50.923Z] GhostDriver - Main - running on port 26515
[INFO  - 2013-07-24T05:21:51.435Z] Session [f235d040-f420-11e2-8d90-f50327bc3449] - CONSTRUCTOR - Desired Capabilities: {"browserName":"phantomjs"}
[INFO  - 2013-07-24T05:21:51.435Z] Session [f235d040-f420-11e2-8d90-f50327bc3449] - CONSTRUCTOR - Negotiated Capabilities: {"browserName":"phantomjs","version":"1.9.1","driverName":"ghostdriver","driverVersion":"1.0.3","platform":"linux-unknown-32bit","javascriptEnabled":true,"takesScreenshot":true,"handlesAlerts":false,"databaseEnabled":false,"locationContextEnabled":false,"applicationCacheEnabled":false,"browserConnectionEnabled":false,"cssSelectorsEnabled":true,"webStorageEnabled":false,"rotatable":false,"acceptSslCerts":false,"nativeEvents":true,"proxy":{"proxyType":"direct"}}
[INFO  - 2013-07-24T05:21:51.435Z] SessionManagerReqHand - _postNewSessionCommand - New Session Created: f235d040-f420-11e2-8d90-f50327bc3449
23:21:51.495 INFO - Done: /session
23:21:51.504 INFO - Executing: org.openqa.selenium.remote.server.handler.GetSessionCapabilities@46b78d at URL: /session/8750a6b4-ec7d-4313-a86d-04ac344b74f2)
23:21:51.505 INFO - Done: /session/8750a6b4-ec7d-4313-a86d-04ac344b74f2
23:21:51.520 INFO - Executing: [get: http://#### REDACTED ####/wp-login.php] at URL: /session/8750a6b4-ec7d-4313-a86d-04ac344b74f2/url)
23:21:51.821 INFO - Done: /session/8750a6b4-ec7d-4313-a86d-04ac344b74f2/url
23:21:51.827 INFO - Executing: [find element: By.selector: #user_login] at URL: /session/8750a6b4-ec7d-4313-a86d-04ac344b74f2/element)
23:21:51.874 INFO - Done: /session/8750a6b4-ec7d-4313-a86d-04ac344b74f2/element
23:21:51.883 INFO - Executing: [send keys: 0 org.openqa.selenium.support.events.EventFiringWebDriver$EventFiringWebElement@20788bf8, [#### REDACTED ####]] at URL: /session/8750a6b4-ec7d-4313-a86d-04ac344b74f2/element/0/value)
23:21:51.939 INFO - Done: /session/8750a6b4-ec7d-4313-a86d-04ac344b74f2/element/0/value
23:21:51.948 INFO - Executing: [find element: By.selector: #user_pass] at URL: /session/8750a6b4-ec7d-4313-a86d-04ac344b74f2/element)
23:21:51.965 INFO - Done: /session/8750a6b4-ec7d-4313-a86d-04ac344b74f2/element
23:21:52.001 INFO - Executing: [send keys: 1 org.openqa.selenium.support.events.EventFiringWebDriver$EventFiringWebElement@20788bf9, [#### REDACTED ####]] at URL: /session/8750a6b4-ec7d-4313-a86d-04ac344b74f2/element/1/value)
23:21:52.065 INFO - Done: /session/8750a6b4-ec7d-4313-a86d-04ac344b74f2/element/1/value
23:21:52.074 INFO - Executing: [find element: By.selector: #wp-submit] at URL: /session/8750a6b4-ec7d-4313-a86d-04ac344b74f2/element)
23:21:52.099 INFO - Done: /session/8750a6b4-ec7d-4313-a86d-04ac344b74f2/element
23:21:52.106 INFO - Executing: [click: 2 org.openqa.selenium.support.events.EventFiringWebDriver$EventFiringWebElement@20788bfa] at URL: /session/8750a6b4-ec7d-4313-a86d-04ac344b74f2/element/2/click)
23:21:52.842 INFO - Done: /session/8750a6b4-ec7d-4313-a86d-04ac344b74f2/element/2/click
23:21:52.850 INFO - Executing: [find element: By.selector: #wpwrap] at URL: /session/8750a6b4-ec7d-4313-a86d-04ac344b74f2/element)
23:21:52.871 INFO - Done: /session/8750a6b4-ec7d-4313-a86d-04ac344b74f2/element

测试失败从Mocha产生以下输出：

[s5rich@host ~]$ mocha test/selenium/acceptance/simple.js


  Wordpress
    1) should be able to log in


  0 passing (2 seconds)
  1 failing

  1) Wordpress should be able to log in:
     Uncaught UnknownError: Error Message => 'Unable to find element with css selector '#wpwrap''
 caused by Request => {"headers":{"Accept":"application/json, image/png","Connection":"Keep-Alive","Content-Length":"42","Content-Type":"application/json; charset=utf-8","Host":"localhost:2897"},"httpVersion":"1.1","method":"POST","post":"{\"using\":\"css selector\",\"value\":\"#wpwrap\"}","url":"/element","urlParsed":{"anchor":"","query":"","file":"element","directory":"/","path":"/element","relative":"/element","port":"","host":"","password":"","user":"","userInfo":"","authority":"","protocol":"","source":"/element","queryKey":{},"chunks":["element"]},"urlOriginal":"/session/77a0a110-f421-11e2-a6fd-61cd002d7d02/element"}
Build info: version: '2.33.0', revision: '4e90c97', time: '2013-05-22 15:32:38'
System info: os.name: 'Linux', os.arch: 'i386', os.version: '2.6.32-042stab076.8', java.version: '1.7.0'
Driver info: driver.version: unknown
      at new bot.Error (/home/s5rich/lib/selenium/node_modules_osx/selenium-webdriver/lib/atoms/error.js:108:18)
      at Object.bot.response.checkResponse (/home/s5rich/lib/selenium/node_modules_osx/selenium-webdriver/lib/atoms/response.js:106:9)
      at /home/s5rich/lib/selenium/node_modules_osx/selenium-webdriver/lib/webdriver/webdriver.js:262:20
      at /home/s5rich/lib/selenium/node_modules_osx/selenium-webdriver/lib/goog/base.js:1112:15
      at webdriver.promise.ControlFlow.runInNewFrame_ (/home/s5rich/lib/selenium/node_modules_osx/selenium-webdriver/lib/webdriver/promise.js:1431:20)
      at notify (/home/s5rich/lib/selenium/node_modules_osx/selenium-webdriver/lib/webdriver/promise.js:315:12)
      at notifyAll (/home/s5rich/lib/selenium/node_modules_osx/selenium-webdriver/lib/webdriver/promise.js:284:7)
      at fulfill (/home/s5rich/lib/selenium/node_modules_osx/selenium-webdriver/lib/webdriver/promise.js:389:7)
      at /home/s5rich/lib/selenium/node_modules_osx/selenium-webdriver/lib/webdriver/promise.js:1298:10
      at /home/s5rich/lib/selenium/node_modules_osx/selenium-webdriver/lib/goog/base.js:1112:15
      at webdriver.promise.ControlFlow.runInNewFrame_ (/home/s5rich/lib/selenium/node_modules_osx/selenium-webdriver/lib/webdriver/promise.js:1431:20)
      at notify (/home/s5rich/lib/selenium/node_modules_osx/selenium-webdriver/lib/webdriver/promise.js:315:12)
      at notifyAll (/home/s5rich/lib/selenium/node_modules_osx/selenium-webdriver/lib/webdriver/promise.js:284:7)
      at fulfill (/home/s5rich/lib/selenium/node_modules_osx/selenium-webdriver/lib/webdriver/promise.js:389:7)
      at /home/s5rich/lib/selenium/node_modules_osx/selenium-webdriver/lib/goog/base.js:1112:15
      at webdriver.promise.ControlFlow.runInNewFrame_ (/home/s5rich/lib/selenium/node_modules_osx/selenium-webdriver/lib/webdriver/promise.js:1431:20)
      at notify (/home/s5rich/lib/selenium/node_modules_osx/selenium-webdriver/lib/webdriver/promise.js:315:12)
      at notifyAll (/home/s5rich/lib/selenium/node_modules_osx/selenium-webdriver/lib/webdriver/promise.js:284:7)
      at fulfill (/home/s5rich/lib/selenium/node_modules_osx/selenium-webdriver/lib/webdriver/promise.js:389:7)
      at /home/s5rich/lib/selenium/node_modules_osx/selenium-webdriver/lib/webdriver/promise.js:600:51
      at /home/s5rich/lib/selenium/node_modules_osx/selenium-webdriver/lib/webdriver/http/http.js:96:5
      at IncomingMessage.<anonymous> (/home/s5rich/lib/selenium/node_modules_osx/selenium-webdriver/http/index.js:113:7)
      at IncomingMessage.EventEmitter.emit (events.js:117:20)
      at _stream_readable.js:910:16
      at process._tickCallback (node.js:415:13)
  ==== async task ====
  WebDriver.findElement(By.cssSelector("#wpwrap"))
      at webdriver.WebDriver.schedule (/home/s5rich/lib/selenium/node_modules_osx/selenium-webdriver/lib/webdriver/webdriver.js:246:15)
      at webdriver.WebDriver.findElement (/home/s5rich/lib/selenium/node_modules_osx/selenium-webdriver/lib/webdriver/webdriver.js:685:17)
      at Context.<anonymous> (/home/s5rich/test/selenium/acceptance/simple.js:12:10)
      at Test.Runnable.run (/usr/local/lib/node_modules/mocha/lib/runnable.js:194:15)
      at Runner.runTest (/usr/local/lib/node_modules/mocha/lib/runner.js:355:10)
      at /usr/local/lib/node_modules/mocha/lib/runner.js:401:12
      at next (/usr/local/lib/node_modules/mocha/lib/runner.js:281:14)
      at /usr/local/lib/node_modules/mocha/lib/runner.js:290:7
      at next (/usr/local/lib/node_modules/mocha/lib/runner.js:234:23)
      at Object._onImmediate (/usr/local/lib/node_modules/mocha/lib/runner.js:258:5)
      at processImmediate [as _immediateCallback] (timers.js:330:15)

测试失败还会从Selenium Server获得以下输出：

23:25:34.742 INFO - Executing: [new session: {browserName=phantomjs}] at URL: /session)
23:25:34.743 INFO - Creating a new session for Capabilities [{browserName=phantomjs}]
23:25:34.744 INFO - executable: /usr/local/bin/phantomjs
23:25:34.744 INFO - port: 2897
23:25:34.744 INFO - arguments: [--webdriver=2897, --webdriver-logfile=/home/s5rich/phantomjsdriver.log]
23:25:34.744 INFO - environment: {}
PhantomJS is launching GhostDriver...
[INFO  - 2013-07-24T05:25:34.879Z] GhostDriver - Main - running on port 2897
[INFO  - 2013-07-24T05:25:35.270Z] Session [77a0a110-f421-11e2-a6fd-61cd002d7d02] - CONSTRUCTOR - Desired Capabilities: {"browserName":"phantomjs"}
[INFO  - 2013-07-24T05:25:35.270Z] Session [77a0a110-f421-11e2-a6fd-61cd002d7d02] - CONSTRUCTOR - Negotiated Capabilities: {"browserName":"phantomjs","version":"1.9.1","driverName":"ghostdriver","driverVersion":"1.0.3","platform":"linux-unknown-32bit","javascriptEnabled":true,"takesScreenshot":true,"handlesAlerts":false,"databaseEnabled":false,"locationContextEnabled":false,"applicationCacheEnabled":false,"browserConnectionEnabled":false,"cssSelectorsEnabled":true,"webStorageEnabled":false,"rotatable":false,"acceptSslCerts":false,"nativeEvents":true,"proxy":{"proxyType":"direct"}}
[INFO  - 2013-07-24T05:25:35.270Z] SessionManagerReqHand - _postNewSessionCommand - New Session Created: 77a0a110-f421-11e2-a6fd-61cd002d7d02
23:25:35.275 INFO - Done: /session
23:25:35.283 INFO - Executing: org.openqa.selenium.remote.server.handler.GetSessionCapabilities@13b4ce4 at URL: /session/b62d0c67-2000-439c-a0bd-f2c100350dee)
23:25:35.284 INFO - Done: /session/b62d0c67-2000-439c-a0bd-f2c100350dee
23:25:35.297 INFO - Executing: [get: http://#### REDACTED ####/wp-login.php] at URL: /session/b62d0c67-2000-439c-a0bd-f2c100350dee/url)
23:25:35.592 INFO - Done: /session/b62d0c67-2000-439c-a0bd-f2c100350dee/url
23:25:35.597 INFO - Executing: [find element: By.selector: #user_login] at URL: /session/b62d0c67-2000-439c-a0bd-f2c100350dee/element)
23:25:35.619 INFO - Done: /session/b62d0c67-2000-439c-a0bd-f2c100350dee/element
23:25:35.631 INFO - Executing: [send keys: 0 org.openqa.selenium.support.events.EventFiringWebDriver$EventFiringWebElement@240035bc, [#### REDACTED ####]] at URL: /session/b62d0c67-2000-439c-a0bd-f2c100350dee/element/0/value)
23:25:35.683 INFO - Done: /session/b62d0c67-2000-439c-a0bd-f2c100350dee/element/0/value
23:25:35.695 INFO - Executing: [find element: By.selector: #user_pass] at URL: /session/b62d0c67-2000-439c-a0bd-f2c100350dee/element)
23:25:35.712 INFO - Done: /session/b62d0c67-2000-439c-a0bd-f2c100350dee/element
23:25:35.723 INFO - Executing: [send keys: 1 org.openqa.selenium.support.events.EventFiringWebDriver$EventFiringWebElement@240035bd, [#### REDACTED ####]] at URL: /session/b62d0c67-2000-439c-a0bd-f2c100350dee/element/1/value)
23:25:35.783 INFO - Done: /session/b62d0c67-2000-439c-a0bd-f2c100350dee/element/1/value
23:25:35.800 INFO - Executing: [find element: By.selector: #wp-submit] at URL: /session/b62d0c67-2000-439c-a0bd-f2c100350dee/element)
23:25:35.822 INFO - Done: /session/b62d0c67-2000-439c-a0bd-f2c100350dee/element
23:25:35.832 INFO - Executing: [click: 2 org.openqa.selenium.support.events.EventFiringWebDriver$EventFiringWebElement@240035be] at URL: /session/b62d0c67-2000-439c-a0bd-f2c100350dee/element/2/click)
23:25:36.105 INFO - Done: /session/b62d0c67-2000-439c-a0bd-f2c100350dee/element/2/click
23:25:36.121 INFO - Executing: [find element: By.selector: #wpwrap] at URL: /session/b62d0c67-2000-439c-a0bd-f2c100350dee/element)
e = java.awt.HeadlessException: 
No X11 DISPLAY variable was set, but this program performed an operation which requires it.
23:25:36.285 WARN - Exception thrown
org.openqa.selenium.NoSuchElementException: Error Message => 'Unable to find element with css selector '#wpwrap''
 caused by Request => {"headers":{"Accept":"application/json, image/png","Connection":"Keep-Alive","Content-Length":"42","Content-Type":"application/json; charset=utf-8","Host":"localhost:2897"},"httpVersion":"1.1","method":"POST","post":"{\"using\":\"css selector\",\"value\":\"#wpwrap\"}","url":"/element","urlParsed":{"anchor":"","query":"","file":"element","directory":"/","path":"/element","relative":"/element","port":"","host":"","password":"","user":"","userInfo":"","authority":"","protocol":"","source":"/element","queryKey":{},"chunks":["element"]},"urlOriginal":"/session/77a0a110-f421-11e2-a6fd-61cd002d7d02/element"}
Command duration or timeout: 149 milliseconds
For documentation on this error, please visit: http://seleniumhq.org/exceptions/no_such_element.html
Build info: version: '2.33.0', revision: '4e90c97', time: '2013-05-22 15:32:38'
System info: os.name: 'Linux', os.arch: 'i386', os.version: '2.6.32-042stab076.8', java.version: '1.7.0'
Session ID: 77a0a110-f421-11e2-a6fd-61cd002d7d02
Driver info: org.openqa.selenium.phantomjs.PhantomJSDriver
Capabilities [{platform=LINUX, acceptSslCerts=false, javascriptEnabled=true, browserName=phantomjs, rotatable=false, driverVersion=1.0.3, locationContextEnabled=false, version=1.9.1, databaseEnabled=false, cssSelectorsEnabled=true, handlesAlerts=false, browserConnectionEnabled=false, proxy={proxyType=direct}, webStorageEnabled=false, nativeEvents=true, driverName=ghostdriver, applicationCacheEnabled=false, takesScreenshot=true}]
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at org.openqa.selenium.remote.ErrorHandler.createThrowable(ErrorHandler.java:191)
    at org.openqa.selenium.remote.ErrorHandler.throwIfResponseFailed(ErrorHandler.java:145)
    at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:554)
    at org.openqa.selenium.remote.RemoteWebDriver.findElement(RemoteWebDriver.java:307)
    at org.openqa.selenium.remote.RemoteWebDriver.findElementByCssSelector(RemoteWebDriver.java:396)
    at org.openqa.selenium.By$ByCssSelector.findElement(By.java:407)
    at org.openqa.selenium.remote.RemoteWebDriver.findElement(RemoteWebDriver.java:299)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.openqa.selenium.support.events.EventFiringWebDriver$2.invoke(EventFiringWebDriver.java:101)
    at $Proxy1.findElement(Unknown Source)
    at org.openqa.selenium.support.events.EventFiringWebDriver.findElement(EventFiringWebDriver.java:180)
    at org.openqa.selenium.remote.server.handler.FindElement.call(FindElement.java:47)
    at org.openqa.selenium.remote.server.handler.FindElement.call(FindElement.java:1)
    at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at org.openqa.selenium.remote.server.DefaultSession$1.run(DefaultSession.java:169)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Caused by: org.openqa.selenium.remote.ScreenshotException: Screen shot has been taken
Build info: version: '2.33.0', revision: '4e90c97', time: '2013-05-22 15:32:38'
System info: os.name: 'Linux', os.arch: 'i386', os.version: '2.6.32-042stab076.8', java.version: '1.7.0'
Driver info: driver.version: EventFiringWebDriver
    at org.openqa.selenium.remote.ErrorHandler.throwIfResponseFailed(ErrorHandler.java:125)
    ... 20 more
Caused by: org.openqa.selenium.remote.ErrorHandler$UnknownServerException: Error Message => 'Unable to find element with css selector '#wpwrap''
 caused by Request => {"headers":{"Accept":"application/json, image/png","Connection":"Keep-Alive","Content-Length":"42","Content-Type":"application/json; charset=utf-8","Host":"localhost:2897"},"httpVersion":"1.1","method":"POST","post":"{\"using\":\"css selector\",\"value\":\"#wpwrap\"}","url":"/element","urlParsed":{"anchor":"","query":"","file":"element","directory":"/","path":"/element","relative":"/element","port":"","host":"","password":"","user":"","userInfo":"","authority":"","protocol":"","source":"/element","queryKey":{},"chunks":["element"]},"urlOriginal":"/session/77a0a110-f421-11e2-a6fd-61cd002d7d02/element"}
Build info: version: '2.33.0', revision: '4e90c97', time: '2013-05-22 15:32:38'
System info: os.name: 'Linux', os.arch: 'i386', os.version: '2.6.32-042stab076.8', java.version: '1.7.0'
Driver info: driver.version: unknown
23:25:36.293 WARN - Exception: Error Message => 'Unable to find element with css selector '#wpwrap''
 caused by Request => {"headers":{"Accept":"application/json, image/png","Connection":"Keep-Alive","Content-Length":"42","Content-Type":"application/json; charset=utf-8","Host":"localhost:2897"},"httpVersion":"1.1","method":"POST","post":"{\"using\":\"css selector\",\"value\":\"#wpwrap\"}","url":"/element","urlParsed":{"anchor":"","query":"","file":"element","directory":"/","path":"/element","relative":"/element","port":"","host":"","password":"","user":"","userInfo":"","authority":"","protocol":"","source":"/element","queryKey":{},"chunks":["element"]},"urlOriginal":"/session/77a0a110-f421-11e2-a6fd-61cd002d7d02/element"}
Build info: version: '2.33.0', revision: '4e90c97', time: '2013-05-22 15:32:38'
System info: os.name: 'Linux', os.arch: 'i386', os.version: '2.6.32-042stab076.8', java.version: '1.7.0'
Driver info: driver.version: unknown

Answer 1

从我看来，这是一个简单的问题需要解决。当发生故障时，您有一个未处理的异常：NoSuchElementException。我不认为您每次都需要重新启动网格节点（假设您正在运行与网格节点实例分开的网格集线器）。可能是从网格节点连续运行浏览器会使用足够多的内存来导致页面出现轻微延迟，从而破坏脚本。您需要做的就是通过将其包装在重试try循环中来优雅地处理NoSuchElementException。您还可以使用.ignoring方法使用FluentWait有效地执行类似操作。

Selenium Webdriver需要重新启动才能始终如一地运行

1 个答案: