how to find response time of end to end requests from logs?

[varshna]

{"line":"10.198.125.217 - - [08/Mar/2019:06:07:17 +0000] \"POST /install/Instere/inser/form HTTP/1.1\" 200 485312","source":"stdout","tag":"abcdef12345","attrs":{"adsk.moniker":"instl-p-ue1","cloudos.portfolio.version":"2.0.200","cloudos.secrets.hash":"****","com.amazonaws.ecs.container-name":"blue","com.amazonaws.ecs.task-arn":"arn:aws:ecs:us-east-1:****:task/*****","com.amazonaws.ecs.task-definition-version":"108","docker.image":"artifactory.pr.awseast.a**.net/abcdcloud/instl:master-abcd1234","docker.tag":"master-abcd1234"}}

[nickhills]

In order to get a response time, you either need:
1.) The event to report it (which I cant see in your example)
2.) A 'start' event, and an 'end' event, and then calculate the difference between the two. - You can use the transaction command to automatically calculate this. https://docs.splunk.com/Documentation/Splunk/7.2.4/SearchReference/Transaction