Mongodb – How restore a specific database from backup using mongorestore command

Sometimes, the 3 config server are out of sync. What does it mean? How can I quickly get rid of these issues?

Most convenient way would be to copy (cp or rsync) the configdb data directory content between hosts in cases of inconsistency

When should I choose MongoDb Shard with Replica Set vs MongoDb Replica set only?

Replica ONLY: When you desire to make your mongo data highly available and add redundancy in your solution. The benefit can be to offload reporting requests to secondary nodes and/or make mongodb cluster sustain network partitions or disaster recovery

Sharding ONLY: When you desire to scale your mongodb cluster horizontally to achieve load balancing and distribute traffic to multiple hosts you must choose sharding. For example, you can achieve partitioning benefits with sharding enabled on databases.

Sharding with replica set: When you desire to enable all benefits stated above i.e. scale you cluster horizontally to handle large volumes of data for load balancing and also achieve HA within each shard you must choose this approach

As at MongoDB 3.2, there is no option for the Windows MSI to only install the mongodump.exe and mongorestore.exe command line tools so a default install is the most straightforward option.

Are there mongodump and mongorestore standalone tools that one could use for this or is it best to install the entire MongoDB package on our build server (which feels like an overkill)?

If you install from a standard (non-Administrator) command prompt, the installer will not be able to create a Windows Service definition so the only overhead will be some extra binary files. In this case you can also use the MSI installer to uninstall or upgrade to newer versions of MongoDB. You will also have additional command line tools available if you want to monitor a deployment (mongostat.exe, mongotop.exe) while you are backup/restoring, and will have mongoimport.exe and mongoexport.exe if you want to import/export JSON or delimited text.

If you want a more minimal install only including specific binaries, you can copy the binaries and the two OpenSSL DLLs which can be found in the bin directory of a full install of MongoDB: ssleay32.dll and libeay32.dll. The DLLs will need to either be in your path or the same directory as the MongoDB .exe files you are running.