Query profiler
Record a database's slow operations in system.profile.
Record a database's slow operations in system.profile to find them later. It works on any node.
Requirements
- A user with
dbAdminon the database.
Turn the profiler on
JavaScript
db.setProfilingLevel(1, { slowms: 50 });Level 1 records the operations slower than slowms milliseconds; level 2, all of them; level 0 turns it off.
Read what was recorded
JavaScript
db.system.profile.find().sort({ ts: -1 }).limit(10);Check
A query slower than 50 ms appears in system.profile with its plan and its duration.
Common problems
- Level 2 records every operation and loads the node; use it only for a while.