Connection issues in Storage trigger GCF - google-cloud-functions

Question

For my application, new file uploaded to storage is read and the data is added to a main file. The new file contains 2 lines, one a header and other an array whose values are separated by a comma. The main file will need maximum of 265MB. The new files will have maximum of 30MB.
def write_append_to_ecg_file(filename,ecg,patientdata):
file1 = open('/tmp/'+ filename,"w+")
file1.write(":".join(patientdata))
file1.write('\n')
file1.write(",".join(ecg.astype(str)))
file1.close()
def storage_trigger_function(data,context):
#Download the segment file
download_files_storage(bucket_name,new_file_name,storage_folder_name = blob_path)
#Read the segment file
data_from_new_file,meta = read_new_file(new_file_name, scale=1, fs=125, include_meta=True)
print("Length of ECG data from segment {} file {}".format(segment_no,len(data_from_new_file)))
os.remove(new_file_name)
#Check if the main ecg_file_exists
file_exists = blob_exists(bucket_name, blob_with_the_main_file)
print("File status {}".format(file_exists))
data_from_main_file = []
if ecg_file_exists:
download_files_storage(bucket_name,main_file_name,storage_folder_name = blob_with_the_main_file)
data_from_main_file,meta = read_new_file(main_file_name, scale=1, fs=125, include_meta=True)
print("ECG data from main file {}".format(len(data_from_main_file)))
os.remove(main_file_name)
data_from_main_file = np.append(data_from_main_file,data_from_new_file)
print("data after appending {}".format(len(data_from_main_file)))
write_append_to_ecg_file(main_file,data_from_main_file,meta)
token = upload_files_storage(bucket_name,main_file,storage_folder_name = main_file_blob,upload_file = True)
else:
write_append_to_ecg_file(main_file,data_from_new_file,meta)
token = upload_files_storage(bucket_name,main_file,storage_folder_name = main_file_blob,upload_file = True)
The GCF is deployed
gcloud functions deploy storage_trigger_function --runtime python37 --trigger-resource patch-us.appspot.com --trigger-event google.storage.object.finalize --timeout 540s --memory 8192MB
For the first file, I was able to read the file and write the data to the main file. But after uploading the 2nd file, its giving Function execution took 70448 ms, finished with status: 'connection error' On uploading the 3rd file, it gives the Function invocation was interrupted. Error: memory limit exceeded. Despite of deploying the function with 8192MB memory, I am getting this error. Can I get some help on this.