copy information to few DB in parallel with single read

correctly I have a code- that take any update on "Source DB" and copy it to "Destination DB"

i think I need make it that with single read call from the "Source DB" and copy in parallel to few "Destination DB"

stream = None
while True:
try:

collection_in = source_db.get_collection(collection_name)
collection_out = destination_db.get_collection(collection_name)

with collection_in.watch(full_document='updateLookup') as stream:

for change in stream:
oper_type = change['operationType']

logger.debug(f"{oper_type} received: {collection_name}")

if oper_type in ignored_ops:
logger.debug(f"{oper_type} operation ignored")
continue

if oper_type == "insert":
callback = db_insert_callback

elif oper_type == "replace":
# db_update_callback(change)
callback = db_update_callback

elif oper_type == "delete":
callback = db_remove_callback

callback(change, collection_out=collection_out)


except Exception as ex:
logger.exception(ex)

finally:
if stream:
stream.close()
example to insert

def db_insert_callback(insert_change, collection_out):
doc = insert_change['fullDocument']
# logger.info(insert_change)
try:
collection_out.insert(doc)
except Exception as ex:
logger.exception(ex)
p

 

I find solution for this may be it can help if anyone faceing same problem like i did.
Here the source.txt contains some data and dest.txt is the file where the data is written. For text files it is done in this way:

f=open('source.txt','r')
g=open('dest.txt','w')

r=f.read()
r=r.split()
for x in r:
g.write(x+' ')

f.close()
g.close()
So, for databases probably using threading connect to the databases with each thread and do the transfers in those thread.
yesornogenerator