Question

I am just restoring a database which I dumped few minutes back to make some changes. Mongorestore taking around 100% CPU and much more time than expected. I thought, it may be due to indexes I created, but, the problem is same while restoring even a single collection. A collection is about 314MB in size and has about 185000 documents.
Usually, this thing does not happen. It might be due to less disk space on my system, but that too is 11GB.
Can anyone help me, what problem it could be?

Note: I’m doing things from mongo client. No driver included.

Answer 1

As you indicated in the comments that this was related to logging, then I would suggest taking a couple of steps:

First, use log rotation. This can be done via a command to the database or by sending the SIGUSR1 signal to the process, so it is very easy to script or enable as a cron job on a regular basis. More information here:

http://www.mongodb.org/display/DOCS/Logging#Logging-Rotatingthelogfiles

Second, verify your logging level. Starting with -v = log level 1; -vv = log leve 2 etc. You can adjust it both at start up and during runtime. For the runtime adjustment, you use the setParameter command:

// connect to the database or mongos
use admin;
// check the log level
db.runCommand({getParameter : 1, logLevel: 1})
{ "logLevel" : 0, "ok" : 1 }
// set it higher
db.runCommand({setParameter : 1, logLevel: 1})
// back to default levels
{ "was" : 0, "ok" : 1 }
db.runCommand({setParameter : 1, logLevel: 0})
{ "was" : 1, "ok" : 1 }

Finally you can also run with –quiet to cut down on some of the messaging also.