Get replicationLag in mongo with pyMongo

Question

I am trying, to get replication-delay using db.rs.printSlaveReplicationInfo from python with pymongo, but not getting any proper way to do so. I tried the following, but no help.

>>>from pymongo import MongoClient
>>>client = MongoClient()
>>>db = client.test_database
>>>db.rs.printSlaveReplicationInfo                 
Collection(Database(MongoClient([u'10.0.0.19:10006', u'10.0.0.68:10002']), u'xyz'), u'rs.printSlaveReplicationInfo')
db.rs.printSlaveReplicationInfo()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib64/python2.7/site-packages/pymongo/collection.py", line 2413, in __call__
    self.__name.split(".")[-1])
TypeError: 'Collection' object is not callable. If you meant to call the 'printSlaveReplicationInfo' method on a 'Collection' object it is failing because no such method exists.
>>> db.rs                            
Collection(Database(MongoClient([u'10.0.0.19:10006', u'10.0.0.68:10002']), u'xyz'), u'rs')

Can anyone help with this? or how to do it?

Thanks in advance.

Answer 1

I found out the answer.Here is the complete code :

(Note: You need to have admin privileges to run this command.)

uri = "mongodb://usernamen:password@host:port/admin"
conn = pymongo.MongoClient(uri)
db = conn['admin']
db_stats = db.command({'replSetGetStatus'  :1})


primary_optime = 0
secondary_optime = 0

for key in db_stats['members'] : 
    if key['stateStr'] == 'SECONDARY' :
        secondary_optime = key['optimeDate']
    if key['stateStr'] == 'PRIMARY' : 
        primary_optime =key['optimeDate']

print 'primary_optime : ' + str(primary_optime)
print 'secondary_optime : ' + str(secondary_optime)

seconds_lag = (primary_optime - secondary_optime ).total_seconds()
#total_seconds() userd to get the lag in seconds rather than datetime object
print 'secondary_lag : ' + str(seconds_lag)

optime reperesents the date,till which that mongo-node has data.

You can read more about it here :

https://docs.mongodb.com/manual/reference/command/replSetGetStatus/