I can't open any system.profile collections record

Working with Data Developer Tools
1

When I go to the system.profile collection from the database, I can see an archive of records. but i cant open a single record. i see a this warning:

Document not found!

I am using a mongo-express web admin panel.

2

db.system.profile will be empty until you specifically set the profiling level. but be careful as it can fill your disk space very fast. you would not want to leave it set to level 2 for long.

check the following page:

2 Likes
3

I noticed you have said you see records but cannot open a single record in it from admin panel. Sorry I missed that.

Have you checked about profiling levels? This is a side effect on how profiling records data and how mongo-express shows documents.

profiling documents are not traditional documents that are not recorded with an _id field. system.profile is written by the server itself and is read-only by users.

on the other hand, mongo-express lists documents but adds a click event to table rows each bearing the _id field of that document. when you click on them, it makes find query with that id.

since system.profile entries does not have an id, that find query just fails hence that error you see.

profiling is for debugging and performance checks, so is better to be used by such tools, not by a general purpose tool. if you have that purpose, do not forget to set the level to 0 after you job ends and then just drop the collection.

db.setProfilingLevel(2)
... wait for operations
db.setProfilingLevel(0)
... now do your analysis
db.system.profile.drop()
... drop so so free disk space
1 Like
4

tnx for reply.

can you explain how we can analysis the profiler results?

5

I am no expert on that, at least for now :slight_smile: I hope these may help.

In addition to above link, you can use this one to know bit more about the fields recorded into the profile documents: Database Profiler Output — MongoDB Manual

There also seems a GUI tool, Query Profiler, for Atlas but “Only available on M10+ clusters and serverless instances”. you can read about it in Monitor Query Performance — MongoDB Atlas

6

Back for the sake of the completeness of the Monitoring tools. I cannot say if they are directly related to a db.system.profile, yet would still be helpful :slight_smile:

1 Like