jmeter scenarios

• Calculate Average, Min and max response time.
• Calculate Number of Transactions with response time >300 ms, <300 ms
• Calculate the % of Error responses.
• Break the server: 
• Source: http://stackoverflow.com/questions/39507765/response-code-non-http-response-code-java-net-connectexception-response-messag
• I am executing one script using Jmeter for load testing.I am getting error in between lets say for eg. If I applied load of 500users, till 250 users threads are running successfully then error comes of connection timed out error.Then, again it running successful for some of threads then error.
• Code is as follow:-
•     Thread Name: Thread Group 1-1274
•     Sample Start: 2016-09-15 15:02:13 IST
•     Load time: 21004
•     Connect Time: 21004
•     Latency: 0
•     Size in bytes: 2206
•     Headers size in bytes: 0
•     Body size in bytes: 2206
•     Sample Count: 1
•     Error Count: 1
•     Data type ("text"|"bin"|""): text
•     Response code: Non HTTP response code: java.net.ConnectException
•     Response message: Non HTTP response message: Connection timed out: connect
• Response headers:
• 
  
• HTTPSampleResult fields:
• ContentType: 
• DataEncoding: null
• I need to break the server.
• 
  
• Can anyone help me for this?