问题
I'm using Apache HttpClient to query HTTP/1.0 (without keep alive) server on localhost with around 20 POST requests/second. I have a TCP_NODELAY enabled like this:
val httpParams = new BasicHttpParams()
HttpConnectionParams.setTcpNoDelay(httpParams, true)
val client = new DefaultHttpClient(connectionManager, httpParams)
Despite that, several times per minute I see a random delay of 10-200 milliseconds for sending such request (measuring on the server shows, that delay is in sending). I checked, that it's not a garbage collector pause. What can be the problem?
I tried to query the server with C++ client with the same rate, and it doesn't have such random delays, so i think it's HttpClient problem.
Update: I checked jetty HttpClient implementation, and it has the same problem. Can this be some problem of JVM on FreeBSD? I should test this on linux, but I don't have a linux server at hand.
回答1:
I have the same problem here using windows. In my case, HttpClient was introducing around 1 second of delay but just at the first attempt to execute a post (I do several in sequence). I try a workaround that was to create a "fake" post to the local host and execute it (and except an IOException). By doing that, my delay when calling real services was reduce from around 1 second to around 100ms. I could not improve more than that yet.
来源：https://stackoverflow.com/questions/5765982/apache-httpclient-random-delays-under-high-requests-second