使用PowerShell的随机WebRequest结果
下面是我脚本中的一段代码,它使用WebRequest ping一个web/app服务器列表,并根据服务器列表中列出的好/坏服务器的顺序得到随机结果 例如,如果坏服务器(我得到的代码是404或503)列在列表的第一位,那么我的脚本似乎可以准确地报告。但是,如果先列出好的服务器(返回status=“OK”),则我的结果不准确 以下是我的代码片段:使用PowerShell的随机WebRequest结果,powershell,webrequest,Powershell,Webrequest,下面是我脚本中的一段代码,它使用WebRequest ping一个web/app服务器列表,并根据服务器列表中列出的好/坏服务器的顺序得到随机结果 例如,如果坏服务器(我得到的代码是404或503)列在列表的第一位,那么我的脚本似乎可以准确地报告。但是,如果先列出好的服务器(返回status=“OK”),则我的结果不准确 以下是我的代码片段: $ServerList = gc "$pwd\servers\test_servers.lst" ForEach ($_ in $ServerList)
$ServerList = gc "$pwd\servers\test_servers.lst"
ForEach ($_ in $ServerList)
{
# Ping web server test
$url = "http://$_.domain.net/logon"
Write-Host "Pinging web address for server: $url ..."
$request = [System.Net.WebRequest]::Create($url)
$response = $request.GetResponse()
If ($response.StatusCode -eq "OK")
{
#$True
Write-Host "Web Ping on $_ Succeeded."
}
Else
{
#$False
Write-Host "Web Ping on $_ FAILED!!!"
}
}
以下是示例服务器列表:
server1 (reports back a 404)
server2 (reports back a 503)
server3 (gets a status = "OK")
下面是我运行脚本时的“精确”cmd输出:
C:\TFS\Sandbox>powershell ./temp.ps1
Pinging web address for server: http://server1.domain.net/wfc/logon ...
Exception calling "GetResponse" with "0" argument(s): "The remote server return
ed an error: (404) Not Found."
At C:\TFS\Sandbox\temp.ps1:8 char:34
+ $response = $request.GetResponse <<<< ()
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : DotNetMethodException
Web Ping on server1 FAILED!!!
Pinging web address for server: http://server2.domain.net/wfc/logon ...
Exception calling "GetResponse" with "0" argument(s): "The remote server return
ed an error: (503) Server Unavailable."
At C:\TFS\Sandbox\temp.ps1:8 char:34
+ $response = $request.GetResponse <<<< ()
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : DotNetMethodException
Web Ping on server2 FAILED!!!
Pinging web address for server: http://server3.domain.net/wfc/logon ...
Web Ping on server3 Succeeded.
当服务器1和服务器2被报告为正常时,我得到的结果不准确:
Pinging web address for server: http://server3.domain.net/wfc/logon ...
Web Ping on server3 Succeeded.
Pinging web address for server: http://server1.domain.net/wfc/logon ...
Exception calling "GetResponse" with "0" argument(s): "The remote server return
ed an error: (404) Not Found."
At C:\TFS\Sandbox\temp.ps1:8 char:34
+ $response = $request.GetResponse <<<< ()
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : DotNetMethodException
Web Ping on server1 Succeeded.
Pinging web address for server: http://server2.domain.net/wfc/logon ...
Exception calling "GetResponse" with "0" argument(s): "The remote server return
ed an error: (503) Server Unavailable."
At C:\TFS\Sandbox\temp.ps1:8 char:34
+ $response = $request.GetResponse <<<< ()
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : DotNetMethodException
Web Ping on server2 Succeeded.
ping服务器的网址:http://server3.domain.net/wfc/logon ...
服务器3上的Web Ping成功。
正在ping服务器的web地址:http://server1.domain.net/wfc/logon ...
使用“0”参数调用“GetResponse”时出现异常:“远程服务器返回”
编辑错误:(404)未找到。“
在C:\TFS\Sandbox\temp.ps1:8 char:34
+$response=$request.GetResponse这是因为WebRequest
在尝试失败时引发异常,$response
在您获得503
、404
等的情况下实际上没有设置。当您获得成功时,响应被设置为响应(状态代码为OK),但是,如果下一个服务器引发404,比如说,响应将仍然是OK状态,因为WebRequest只引发一个异常,并且没有为$response分配任何内容。您可能希望捕获
(或尝试捕获
)异常并在那里处理成功或失败,或者在循环的每次迭代中将$response
设置为null:
foreach($server in $serverlist){
$response=$null
...
另外,不要使用$\uuu
作为迭代变量,它是自动变量,在这里使用它并不好
请注意,您所写的内容也可能会占用系统资源(对我来说它挂起了一次),因此请适当地处理响应$response=$null可能就足够了,但在循环结束时,您可能仍然需要正确关闭响应。您可能需要关闭连接:
$response.Close()
我会这样写:
foreach ($server in $ServerList) {
try {
$url = "http://${server}.domain.net/logon"
Write-Host "Pinging web address for server: $url ..."
$request = [System.Net.WebRequest]::Create($url)
$response = $request.GetResponse()
Write-Host "Web Ping on $server Succeeded."
} catch {
Write-Host ("Web Ping on $server FAILED!!! The error was '{0}'." -f $_)
} finally {
if ($response) {
$response.Close()
Remove-Variable response
}
}
}
虽然关闭响应很好,但这并不能解决OP的问题,即为失败的返回成功。@manojlds我添加了一个删除变量
,以防它在赋值时未被置为空。@AndyArismendi--也感谢您的反馈。我也尝试过你的解决方案,效果很好@基思:没问题,我对它进行了一点全面的更新。这对我解决另一个问题有所帮助。非常感谢+1手册——感谢您的反馈。非常有用,$response=$null
工作得非常好!
foreach ($server in $ServerList) {
try {
$url = "http://${server}.domain.net/logon"
Write-Host "Pinging web address for server: $url ..."
$request = [System.Net.WebRequest]::Create($url)
$response = $request.GetResponse()
Write-Host "Web Ping on $server Succeeded."
} catch {
Write-Host ("Web Ping on $server FAILED!!! The error was '{0}'." -f $_)
} finally {
if ($response) {
$response.Close()
Remove-Variable response
}
}
}