Timed out waiting on socket read. (Mongo::OperationTimeout)

[HellBakedMiasma]

I have two mysql databases, one is relatively small (db1), about 500 000 records, the second contains more than 3.5 million records (db2).

Using mongify to copy the first into mongodb succeeds as intented, while copying the latter yields the following error after having created the tables, copied the records, updated the references, and removed "pre_mongified_id"s from half the collections :

/var/lib/gems/2.3.0/gems/mongo-1.12.5/lib/mongo/networking.rb:336:in `rescue in receive_message_on_socket': Timed out waiting on socket read. (Mongo::OperationTimeout)

i'm on debian stretch using mongodb version 3.2.11.

[anlek]

Could be an issue with RAM... maybe manually remove the pre_mongified_id field? or is other data missing?

[Dylan2388]

I'm facing the same above error. Where can I remove the pre_mongified_id field manually?

[anlek]

pre_mongified_id gets removed as the last step of the move process