CODEWITHSUNDEEP
c++aws-lambdaaws-sdk
Bowie Owens
Bowie Owens

Reputation: 2976

AWS Lambda C++ SDK "Process exited before completing request"

I have created a function "gen_MC_calculate_compound". When I call aws lambda list-functions I get:

{
    "Functions": [
        {
            "FunctionName": "gen_MC_calculate_compound",
            ...
        }
}

At the moment it is the hello world example:

#include <aws/lambda-runtime/runtime.h>

using namespace aws::lambda_runtime;

invocation_response my_handler(invocation_request const& request)
{
   return invocation_response::success("Hello, World!", "application/json");
}

int main()
{
   run_handler(my_handler);
   return 0;
}

I can invoke it from the command line with:

aws lambda invoke --function-name gen_MC_calculate_compound out.txt

and I get a successful result:

{
    "StatusCode": 200,
    "ExecutedVersion": "$LATEST"
}

I have in the following code to invoke using C++ SDK:

    Aws::Lambda::Model::InvokeRequest invokeRequest;
    invokeRequest.SetFunctionName("gen_MC_calculate_compound");

    // RequestResponse == synchronous
    invokeRequest.SetInvocationType(
        Aws::Lambda::Model::InvocationType::RequestResponse);

    // Tail == logging on
    invokeRequest.SetLogType(Aws::Lambda::Model::LogType::Tail);

    {
        auto const payload_json = to_json(args);

        auto const payload_ss = std::make_shared<Aws::StringStream>();

        *payload_ss << payload_json.View().WriteReadable();

        invokeRequest.SetBody(payload_ss);
        invokeRequest.SetContentType("application/javascript");
    }

    std::cerr << "invoke AWS...";
    auto outcome = lambda_->Invoke(invokeRequest);

The invoke succeeds but I get an error:

{"errorMessage":"RequestId: 7c208ba7-c221-430a-b0ca-d67fbfc0e475 Process exited before completing request"}
Log result header:
START RequestId: 7c208ba7-c221-430a-b0ca-d67fbfc0e475 Version: $LATEST
[ERROR] [1930427] LAMBDA_RUNTIME Failed to get next invocation. No Response from endpoint
END RequestId: 7c208ba7-c221-430a-b0ca-d67fbfc0e475
REPORT RequestId: 7c208ba7-c221-430a-b0ca-d67fbfc0e475  Duration: 35.81 ms      Billed Duration: 100 ms         Memory Size: 128 MB     Max Memory Used: 33 MB
RequestId: 7c208ba7-c221-430a-b0ca-d67fbfc0e475 Process exited before completing request

What am I doing differently in the C++ SDK vs the command line that is causing the execution to fail? Alternatively, any hints on how to diagnose this further would be helpful.

Upvotes: 1

Views: 562

Answers (1)

Marco M.
Marco M.

Reputation: 3106

I think you need to rewind the stream before passing it to SetBody.


        payload_ss->seekg(0, payload_ss->beg); // rewind the stream

        invokeRequest.SetBody(payload_ss);

Upvotes: 1

Related Questions