MongoDB secondary started accepting queries before syncing(replSet still syncing, not yet to minValid optime)

[Manoj Vivek]

Hi, I have brought up a new replica from EBS snapshot(2 days old) of an existing secondary and then added it to the replicaset using rs.add(). But once added it started serving queries even before fully syncing with the primary. I guess this is shouldn't be the expected behaviour. Is it a bug? MongoDB version - 2.6.11

I have attached the logs below.

 

2016-08-23T05:32:42.470+0000 [rsBackgroundSync] replSet syncing to: 10.0.1.211:27017
2016-08-23T05:32:42.470+0000 [rsSync] replSet still syncing, not yet to minValid optime 57bb0c9d:f
2016-08-23T05:32:42.471+0000 [rsBackgroundSync] replset setting syncSourceFeedback to 10.0.1.211:27017
2016-08-23T05:32:43.635+0000 [initandlisten] connection accepted from 127.0.0.1:43066 #104 (104 connections now open)
2016-08-23T05:32:43.636+0000 [conn104]  authenticate db: admin { authenticate: 1, nonce: "xxx", user: "admin", key: "xxx" }
2016-08-23T05:32:51.112+0000 [rsSync] replSet SECONDARY
2016-08-23T05:32:51.182+0000 [initandlisten] connection accepted from 10.0.0.31:39528 #105 (105 connections now open)
2016-08-23T05:32:51.188+0000 [conn105]  authenticate db: <db> { authenticate: 1, user: <user>, nonce: "xxx", key: "xxx" }
2016-08-23T05:32:51.190+0000 [initandlisten] connection accepted from 10.0.0.31:39530 #106 (106 connections now open)
2016-08-23T05:32:51.190+0000 [conn106]  authenticate db: <db> { authenticate: 1, user: <user>, nonce: "xxx", key: "xxx" }
2016-08-23T05:32:51.357+0000 [initandlisten] connection accepted from 10.0.0.31:39542 #107 (107 connections now open)
2016-08-23T05:32:51.357+0000 [initandlisten] connection accepted from 10.0.0.31:39544 #108 (108 connections now open)
2016-08-23T05:32:51.357+0000 [conn107]  authenticate db: <db> { authenticate: 1, user: <user>, nonce: "xxx", key: "xxx" }
2016-08-23T05:32:51.357+0000 [conn108]  authenticate db: <db> { authenticate: 1, user: <user>, nonce: "xxx", key: "xxx" }
2016-08-23T05:32:51.431+0000 [conn105] query <db.coll> query: { <query> } planSummary: IDHACK ntoskip:0 nscanned:1 nscannedObjects:1 idhack:1 keyUpdates:0 numYields:1 locks(micros) r:336 nreturned:1 reslen:2081 131ms
2016-08-23T05:32:51.455+0000 [initandlisten] connection accepted from 10.0.0.31:39558 #109 (109 connections now open)
2016-08-23T05:32:51.456+0000 [conn109]  authenticate db: <db> { authenticate: 1, user: <user>, nonce: "xxx", key: "xxx" }
2016-08-23T05:32:51.463+0000 [conn107] query <db.coll> query: { <query> } planSummary: IXSCAN { <index> } ntoreturn:0 ntoskip:0 nscanned:1 nscannedObjects:1 keyUpdates:0 numYields:1 locks(micros) r:206862 nreturned:1 reslen:367 104ms
2016-08-23T05:32:51.534+0000 [initandlisten] connection accepted from 10.0.0.41:46923 #110 (110 connections now open)

Made a workaround by removing and making a hidden secondary till it got synced.

Any help appreciated.

Thanks,

Manoj Vivek