When a command with a large command object is run and the operation is logged, the message "query not recording (too large)" is recorded in the log line instead of the abbreviated command object.
To reproduce, run the following snippet with the mongo shell:
When run against a 2.6.5 mongod with the verbose flag set, this command generates the following entry in the mongod log:
This is a regression introduced in 2.5.5 by <https://github.com/mongodb/mongo/commit/bc25799bbeaee8e6133804ffa6fece31e8a62236#diff-96c987e2693d90345a318d2681e2c45eR604>. The issue is that the command object is read out of CurOp::_query (which is limited in size) instead of OpDebug::query.
When run against 2.4.12, an abbreviated version of the query is logged instead, as expected: