保持与rcurl的连接打开

我正在连接一台服务器以发出数千个请求。根据我所看到的，看起来RCurl在每次请求时都会打开到服务器的连接。我想知道是否有一种方法可以让连接在一定的时间内保持打开状态。下面是我在一秒内运行两个请求时看到的情况

* About to connect() to gt-tradeview port 80 (#0)
*   Trying 192.168.141.136... * connected
* Connected to gt-tradeview (192.168.141.136) port 80 (#0)
> POST /House/TradeView/ajax/varys HTTP/1.1
User-Agent: RCurl
Host: gt-tradeview
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
Accept: application/json
Content-Length: 360

< HTTP/1.1 200 OK
< Content-Length: 1690
< Content-Type: application/json
< Server: Microsoft-HTTPAPI/2.0
< Date: Thu, 09 Jan 2014 14:27:49 GMT
< 
* Connection #0 to host gt-tradeview left intact


* About to connect() to gt-tradeview port 80 (#0)
*   Trying 192.168.141.136... * connected
* Connected to gt-tradeview (192.168.141.136) port 80 (#0)
> POST /House/TradeView/ajax/varys HTTP/1.1
User-Agent: RCurl
Host: gt-tradeview
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
Accept: application/json
Content-Length: 227

< HTTP/1.1 200 OK
< Content-Length: 195
< Content-Type: application/json
< Server: Microsoft-HTTPAPI/2.0
< Date: Thu, 09 Jan 2014 14:27:49 GMT
< 
* Connection #0 to host gt-tradeview left intact

所以没有任何连接打开

这是我的卷发

mkURL <- function(x) {
  names <- names(x)

  s <- sprintf("%s=%s",names[1],x[1])
  for (i in 2:length(names)) {
    s <- sprintf("%s&%s=%s",s,names[i],x[i])
  }
  URLencode(s)
}
curl.opts = curlOptions(
  httpheader = c(
    'Content-Type'    = "application/x-www-form-urlencoded; charset=UTF-8",
    'Accept'          = "application/json"
   #'Accept-Encoding' = "gzip,deflate,sdch"
  ),
  verbose = TRUE,  #change to TRUE for server feedback
  header = TRUE,
  buffersize = 100000000000,
  useragent = "RCurl"                                                       ###
) 

---

什么是

r$curl（）

？您是否最终调用了一次

getCurlHandle

，然后重新使用返回的值？也许您可以将范围缩小一点（根据需要编辑您的问题），例如，缩小到导致问题的特定（可公开访问的）服务器/协议。这显然会重新使用连接--

curlPerform（url=”http://stackoverflow.com/questions/21023439/keep-connection-open-with-rcurl“，nobody=TRUE，verbose=TRUE，curl=r$curl（））

当您说它重复使用连接时，这是否意味着后续请求会更快？运行该选项后，showconnections（）是否仍然不显示任何内容？如果是这样，showconnections（）做什么？

showconnections

是关于基本的R连接（

file（）

，

url（）

，等等，请参见

？连接

）；不幸的是，与RCurl无关。我通过重复

curlPerform（）

并查找报告“即将连接…”（创建新的curl连接）或“重新使用现有连接…”（重新使用以前建立的curl连接）的输出来衡量重用性。好的，所以可以安全地假设这个特定的服务器正在关闭连接，因为您唯一的更改是从不同的服务器请求？

mkURL <- function(x) {
  names <- names(x)

  s <- sprintf("%s=%s",names[1],x[1])
  for (i in 2:length(names)) {
    s <- sprintf("%s&%s=%s",s,names[i],x[i])
  }
  URLencode(s)
}
curl.opts = curlOptions(
  httpheader = c(
    'Content-Type'    = "application/x-www-form-urlencoded; charset=UTF-8",
    'Accept'          = "application/json"
   #'Accept-Encoding' = "gzip,deflate,sdch"
  ),
  verbose = TRUE,  #change to TRUE for server feedback
  header = TRUE,
  buffersize = 100000000000,
  useragent = "RCurl"                                                       ###
) 

curlPerform(url = paste0("http://",serverToHit,"/House/TradeView/ajax/varys"),
      #curlPerform(url = "http://192.168.141.148/House/TradeView/ajax/varys",
                postfields = mkURL(parameters),
                .opts = curl.opts,
                writefunction = r$update,
                post = 1L,
                curl = r$curl())