I'm trying to implement a limited web crawler in C# (for a few hundred sites only) using HttpWebResponse.GetResponse() and Streamreader.ReadToEnd() , also tried using StreamReader.Read() and a loop to build my HTML string.
I'm only downloading pages which are about 5-10K.
It's all very slow! For example, the average GetResponse() time is about half a second, while the average StreamREader.ReadToEnd() time is about 5 seconds!
All sites should be very fast, as they are very close to my location, and have fast servers. (in Explorer takes practically nothing to D/L) and I am not using any proxy.
My Crawler has about 20 threads reading simultaneously from the same site. Could this be causing a problem?
How do I reduce StreamReader.ReadToEnd times DRASTICALLY?
HttpWebRequest may be taking a while to detect your proxy settings. Try adding this to your application config:
<system.net>
<defaultProxy enabled="false">
<proxy/>
<bypasslist/>
<module/>
</defaultProxy>
</system.net>
You might also see a slight performance gain from buffering your reads to reduce the number of calls made to the underlying operating system socket:
using (BufferedStream buffer = new BufferedStream(stream))
{
using (StreamReader reader = new StreamReader(buffer))
{
pageContent = reader.ReadToEnd();
}
}