5

I want to see oplog so I have started MongoDB with as suggested in here

mongod --master --port 8888 --dbpath ...

But when I run

>db.oplog.rs.find()

It returns nothing

When I run 

>db.oplog.rs.stats()

returns error 

{
"ok" : 0,
"errmsg" : "ns not found"
}

I have also tried these commands with '>use local'. I see same results.I am planning to read it using java oplog watcher API. But not able to get it. What am I missing.How to see oplog.

Maria
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  • It would have been helpful to pass that link in the other question instead of just ignoring me, not replying, and then opening a new question. With that knowledge of a deprecated tech (I don't usually store active knowledge of deprecated techs) I was able to get to the bottom of it quickly. – Sammaye Mar 06 '14 at 11:31

2 Answers2

12

"oplog.rs" is found in the "local" database. So, you can try something like:

use local
db.oplog.rs.find()

or from a different database:

db.getSiblingDB("local").oplog.rs.find()
Anand Jayabalan
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2

Ok so it isn't replica set when you use --master it is actually the deprecated master-slave replication which got me thinking that maybe it is just a different name:

> show collections
oplog.$main
startup_log
> db.oplog.$main.find()
{ "ts" : Timestamp(1394104629, 1), "op" : "n", "ns" : "", "o" : {  } }
{ "ts" : Timestamp(1394104643, 1), "op" : "n", "ns" : "", "o" : {  } }
{ "ts" : Timestamp(1394104653, 1), "op" : "n", "ns" : "", "o" : {  } }
{ "ts" : Timestamp(1394104663, 1), "op" : "n", "ns" : "", "o" : {  } }
{ "ts" : Timestamp(1394104673, 1), "op" : "n", "ns" : "", "o" : {  } }
{ "ts" : Timestamp(1394104683, 1), "op" : "n", "ns" : "", "o" : {  } }
{ "ts" : Timestamp(1394104693, 1), "op" : "n", "ns" : "", "o" : {  } }

Turns out I was right.

Sammaye
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  • Yes you are absolutely right !! Anyway I am using 'one member replica set' as you suggested in http://stackoverflow.com/questions/22218175/selective-replication-in-mongodb . – Maria Mar 06 '14 at 13:06