我目前正在使用包doParallel以parallelise我RSelenium网站刮板(泊坞上运行)。我发现这个职位(Speed up web scraping using multiplie Rselenium browsers)和我通过复制在@hdharrison这里给出了答案:
library(RSelenium)
library(rvest)
library(magrittr)
library(foreach)
library(doParallel)
# using docker run -d -p 4445:4444 selenium/standalone-chrome:3.5.3
# in windows
URLsPar <- c("https://stackoverflow.com/", "https://github.com/",
"http://www.bbc.com/", "http://www.google.com",
"https://www.r-project.org/", "https://cran.r-project.org",
"https://twitter.com/", "https://www.facebook.com/")
appHTML <- c()
(cl <- (detectCores() - 1) %>% makeCluster) %>% registerDoParallel
# open a remoteDriver for each node on the cluster
clusterEvalQ(cl, {
library(RSelenium)
remDr <- remoteDriver(remoteServerAddr = "192.168.99.100", port = 4445L,
browserName = "chrome")
remDr$open()
})
ws <- foreach(x = 1:length(URLsPar),
.packages = c("rvest", "magrittr", "RSelenium")) %dopar% {
print(URLsPar[x])
remDr$navigate(URLsPar[x])
remDr$getTitle()[[1]]
}
> ws
[[1]]
[1] "Stack Overflow - Where Developers Learn, Share, & Build Careers"
[[2]]
[1] "The world's leading software development platform · GitHub"
[[3]]
[1] "BBC - Homepage"
[[4]]
[1] "Google"
[[5]]
[1] "R: The R Project for Statistical Computing"
[[6]]
[1] "The Comprehensive R Archive Network"
[[7]]
[1] "Twitter. It's what's happening."
[[8]]
[1] "Facebook - Log In or Sign Up"
# close browser on each node
clusterEvalQ(cl, {
remDr$close()
})
stopImplicitCluster()
这似乎是我寻求的解决方案,但是当我运行它,我碰到过这样的错误信息:
错误checkForRemoteErrors(lapply(CL,recvResult)):
3个节点产生的错误;第一个错误:在HTTR调用未定义的错误。 HTTR输出:无法连接到192.168.99.100端口4445:连接被拒绝
这是“泊坞窗PS”的输出:
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
f2d62f6b293b selenium/standalone-chrome:3.5.3 "/opt/bin/entry_poin…" 36 minutes ago Up 35 minutes 0.0.0.0:4445->4444/tcp recursing_austin
我明白,我将不得不打开每个核心一个新的浏览器,但我认为这其中的问题是:我减少我的核心上的那一刻,我获得较少产生的错误。
如果我可以提供任何更多的细节,请让我知道!提前致谢!
在平均时间,我能想出如何解决我的错误。如果其他人也面临同样的问题,我在这里留下意见。我无法解释的逻辑背后,但我的代码运行正常,当我更换
remDr <- remoteDriver(remoteServerAddr = "192.168.99.100", port = 4445L,
browserName = "chrome")
通过
remDr <- remoteDriver(port = 4445L)
并使用Firefox浏览器,而不是浏览器。