AWS Lambda multiple threads and boto3

Question

I am writing a AWS Lambda function that deletes 100,000 objects per lambda function call from S3 bucket. I am trying to see if I can create and run the deletion on a background threads. I have the following code.

import boto3
import boto3.session
from threading import Thread

http_response = []
MAX = 999
threads = []

class myThread(Thread):
  def __init__(self, objects_to_delete, bucket_name):
    Thread.__init__(self)

    self.objects_to_delete = objects_to_delete
    self.bucket_name = bucket_name

  def run(self):
    session = boto3.session.Session().client('s3')
    s3 = session.client('s3')

    #### 
     COMES HERE AND PRINTS THE NAME OF THE BUCKET.
    ####
    print(self.bucket_name)

    response = s3.delete_objects(Bucket=bucket_name, Delete={'Objects': objects_to_delete[0:MAX] })

    #### 
      THIS IS NOT GETTING PRINTED. MEANING, delete_object IS BREAKING/NOT EXECUTING
    ####
    print(response)


def handler(event, context):

  keys = event['keys']
  bucket_name = event["bucket"]

   if (len(keys) == 0 or len(bucket_name) == 0):
    return {
        "message": http_response
    }

try:
        t = myThread(objects_to_delete[0:MAX], bucket_name)
        t.start()
        threads.append(t)

except:
    print("Something Went wrong!!! " + str(objects_to_delete))


del keys[0:MAX]

 for i in range(len(threads)):
     threads[i].start()


handler({'keys': keys, 'bucket': bucket_name}, context)

Is there anything wrong I am doing here? Seems like thread is starting, however it's not making the "delete_objects" call. It's not even returning any error messages to learn about the error. Any thoughts or ideas?

One more thing, when I run this function locally on my computer, it runs just fine without any problem.

Answer 1

turns out after starting a thread, you should join them because, once the process quits, the threads die as well. So I did the following

import boto3
from threading import Thread

MAX = 999
threads = []

class myThread(Thread):
    def __init__(self, bucket_name, objects):
        Thread.__init__(self)
        self.bucket_name = bucket_name
        self.objects = objects

def run(self):
    s3 = boto3.client('s3', region_name="us-east-1")
    response = s3.delete_objects(Bucket=self.bucket_name, Delete={'Objects':self.objects})
    print(response)


 def handler(event, context):

   keys = event["keys"]
   bucket_name = event["bucket"]

   objects_to_delete = [1...100,000]

   while (len(objects_to_delete) != 0):
      t = myThread(bucket_name, objects_to_delete[0:MAX])
      threads.append(t)
      del objects_to_delete[0:MAX]


    for thread in threads:
       thread.start()

    for thread in threads:
       thread.join()

    return {
       "message": "Success Message."
    }