Capture start and end of lambda functions - amazon-web-services

Question

Is it possible to capture the startTime and endTime of execution of lambda functions along with parameters that were passed to it ?
I couldn't find any state-change event configurations that could be configured to send events when lambda function starts/terminates?
A crappy alternative is to record parameters & start time in database when the lambda is being invoked and have the lambda update the endgame as final step before it's completion. This appears prone to failures scenarios like function erroring out before updating DB.
Are there other alternatives to capture this information

Answer 1

aws x-ray may be a good solution here. It is easy to integrate and use. You may enable it aws console.
Go to your lambda function/ configuration tab
Scroll down & in AWS X-Ray box choose active tracing.
Without any configuration in the code, it is going to record start_time and end_time of the function with additional meta data. You may integrate it as a library to your lambda function and send additional subsegments such as request parameters. Please check here for documentation
Here is a sample payload;
{
"trace_id" : "1-5759e988-bd862e3fe1be46a994272793",
"id" : "defdfd9912dc5a56",
"start_time" : 1461096053.37518,
"end_time" : 1461096053.4042,
"name" : "www.example.com",
"http" : {
"request" : {
"url" : "https://www.example.com/health",
"method" : "GET",
"user_agent" : "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/601.7.7",
"client_ip" : "11.0.3.111"
},
"response" : {
"status" : 200,
"content_length" : 86
}
},
"subsegments" : [
{
"id" : "53995c3f42cd8ad8",
"name" : "api.example.com",
"start_time" : 1461096053.37769,
"end_time" : 1461096053.40379,
"namespace" : "remote",
"http" : {
"request" : {
"url" : "https://api.example.com/health",
"method" : "POST",
"traced" : true
},
"response" : {
"status" : 200,
"content_length" : 861
}
}
}
]
}