"exhausting cursor" while attempting db.copyDatabase()

[Wes]

Good afternoon, everybody.

I'm moving one of our development Mongo instances from 2.0 to 2.4, across a VPN link between datacenters.  Latency isn't too bad, so I don't that that's the problem.

Doing a:

devmongo01:PRIMARY> db.copyDatabase("blabla","blabla","devmongocluster-a","copyuser","CopyThatData");

results in:
    "errmsg" : "exception: recv failed while exhausting cursor",
    "code" : 16465,
    "ok" : 0


The total DB size here is about 10G. Sometimes this makes it 1G through, sometimes 5.  I kept trying it hoping it would eventually succeed but haven't had any luck yet.  Any thoughts?

Thanks!

Wes

[Mike Friedman]

Hi Wes,

Without looking in detail at your logs, my suspicion would be that your VPN connection is just not reliable enough to execute an online copy of a 10GB database without a hiccup along the way. You should also be aware that a copyDatabase operation does not provide a point-in-time snapshot and could result in the two copies being inconsistent if there are writes to the origin database during the copy.

Have you tried copying the database by doing a mongodump and mongorestore? That would probably be faster since you could compress the resulting dumped file before transmitting it.


Mike

[Wes]

Howdy, Mike.

I'm trying that now, actually.  This VPN *should* be reliable; it's over leased lines using real gear.  But if not, at least I can yell at the network guy.  If the VPN theory is correct, would you expect it to be related to latency or straight packet loss?  We're doing a ton of other traffic that's been reliable over the same link (like SAN replication) so I'm hesitant to blame the VPN.  Yet.. : )

Thanks!

Wes

[Wes]

This was an authentication problem, somehow.  A normal mongodump also failed, but when running as an adminy-account it works.  That seems incorrect, but at least it's working.

Wes