title: How to stop/control events triggered by AWS S3 on Object upload for invoking AWS Lambda?
body: <p>I'm currently uploading a file into AWS S3 Bucket(B1) with 250 MB size &amp; 1 Million records. This triggers a Lambda (L1 - 1.5GB, 3 Mins) which reads this file &amp; grouping the records with some criteria &amp; writing about 25K files into S3 again on the different bucket(B2).</p>
  
  <p>Now, notification event configured on Bucket (B2) generates 25K events(requests) to different Lambda (L2 - 512MB, 2Mins, Concurrency-2). This Lambda calls a Java-based micro-service which makes an entry into DB after processing which takes about 1-2 seconds for each call.</p>
  
  <p>The problem here is, Once 2nd Lambda (L2) is triggered, there's no way to stop it. It runs for hours &amp; not receiving any other event for the same lambda until processing all events completely &amp; I've no control over S3 events triggered already.</p>
  
  <p>Can someone please explain how events triggered on S3 upon file upload being processed (architecture) on Amazon S3 &amp; how to get fine-grained control over S3 events triggered?</p>
  
  <p>Is there anything I can do on AWS Lambda side to stop S3 events triggered already?</p>