Mongo primary is showing behind the primary? - mongodb

Question

Mongo primary is showing behind the primary ?? Its increasing as time passes . Please suggest ?
monRepl:PRIMARY> rs.printSlaveReplicationInfo()
source: xxxxxx:27017
syncedTo: Mon Apr 27 2015 10:39:02 GMT+0530 (IST)
**25835 secs (7.18 hrs) behind the primary**
monRepl:PRIMARY> rs.status();
{
"set" : "monRepl",
"date" : ISODate("2015-04-27T12:20:38Z"),
"myState" : 1,
"members" : [
{
"_id" : 3,
"name" : "xxxxx:27017",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 329104,
"optime" : Timestamp(1430111629, 90),
"optimeDate" : ISODate("2015-04-27T05:13:49Z"),
"lastHeartbeat" : ISODate("2015-04-27T12:20:36Z"),
"lastHeartbeatRecv" : ISODate("2015-04-27T12:20:37Z"),
"pingMs" : 0,
"syncingTo" : "yyyyyy:27017"
},
{
"_id" : 5,
"name" : "xxxxxx:27017",
"health" : 1,
"state" : 7,
"stateStr" : "ARBITER",
"uptime" : 329104,
"lastHeartbeat" : ISODate("2015-04-27T12:20:38Z"),
"lastHeartbeatRecv" : ISODate("2015-04-27T12:20:37Z"),
"pingMs" : 0
},
{
"_id" : 6,
"name" : "yyyyyyy:27017",
"health" : 1,
"state" : 1,
"stateStr" : "PRIMARY",
"uptime" : 579120,
"optime" : Timestamp(1430137238, 300),
"optimeDate" : ISODate("2015-04-27T12:20:38Z"),
"electionTime" : Timestamp(1429808169, 7),
"electionDate" : ISODate("2015-04-23T16:56:09Z"),
"self" : true
}
],
"ok" : 1
}

Answer 1

It's the secondary which is behind the primary. You can tell by comparing the optimeDate of the primary (2015-04-27T12:20:38Z) with the optimeDate of the secondary (2015-04-27T05:13:49Z). As you can see, the difference is about 7.18 hours.
For why the secondary is so far behind the primary... good question. There are a ton of possible reasons.