Number of Request crosses number of active user. Always results in error.

I am using below-mentioned setup.

val httpConf = http.baseUrl(“http://” + Configuration.host)
.acceptHeader(“application/json”)
//.doNotTrackHeader(“1”)
//.acceptEncodingHeader(“gzip, deflate”)
//.userAgentHeader(“Mozilla/5.0 (Windows NT 5.1; rv:31.0) Gecko/20100101 Firefox/31.0”)
.disableCaching

setUp(
scn.inject(
rampConcurrentUsers(30) to (1000) during (3 minutes)).protocols(httpConf))

and I am getting following errors:

With more user, I am getting more connection timeouts.

I have an event-driven system wherein I could get bulk request at a given time. Currently, we are looking at concurrent bulk request as well.