What the difference "latency time" VS "Connect Time" In Jmeter?

Question

I am user jmeter 3.1 I am unclear the difference of "Latency time" vs "connected time", In fact, in jmeter official document, it said :

New connect time metric

"connectTime " represents the time to establish connection. By default it is not saved to CSV or XML, to have it saved add to user.properties:

jmeter.save.saveservice.connect_time=true

So, what the mean of "latency time"?

Answer 1

Connect Time: time taken to establish TCP connection (at TCP layer in TCP/IP model) b/w client and server using TCP Handshake. If TCP Handshake is successful, then the client can send further requests (HTTP request - HTTP layer). If not, the client can't talk to the server. This can happen if the server is not live or busy responding other requests.

Latency Time: JMeter measures the latency from just before sending the request to just after the first response has been received. (Connect time is included while calculating Latency Time)

Elapsed time: JMeter measures the elapsed time from just before sending the request to just after the last response has been received

References:

1. https://jmeter.apache.org/usermanual/glossary.html
2. http://www.tcpipguide.com/free/t_TCPConnectionEstablishmentProcessTheThreeWayHandsh-3.htm