Unable run my test file when I have increased the num of users

[seshendramln]

Hi
In my test file when I increase the num of users I was getting the warning that "WARN: Error during HTTP request: Error: ECONNREFUSED, Could not contact DNS servers" and Iam unable rectify the problem so please help me in solving this error.

nl.run({
name: "test",
host: 'http://91.123.195.57/',
port: 9200,
numUsers: 2000, //Increased my num of user
timeLimit: 180,
targetRps: 500,
stats: [
'result-codes',
{ name: 'latency', percentiles: [0.9, 0.99] },
'concurrency',
'rps',
'uniques',
{ name: 'http-errors', successCodes: [200,404], log: 'http-errors.log' }
],