Q. Logs from unused collections

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1

I’m planning to drop unused collections.
Before that, I checked the log messages and found two patterns of log messages below.

  • command <db>.<collections> command: getMore { getMore: 3165246867793876361, collection: “<collections>”, $readPreference: { mode: “secondaryPreferred” }, $db: “<db>” } originatingCommand: { find: UUID(“<UUID>”), noCursorTimeout: true, $readPreference: { mode: “secondaryPreferred” }, $db: “<db>” } planSummary: COLLSCAN cursorid:3165246867793876361 keysExamined:0 docsExamined:123945 numYields:968 nreturned:123945 reslen:16777435 locks:{ ReplicationStateTransition: { acquireCount: { w: 969 } }, Global: { acquireCount: { r: 969 } }, Database: { acquireCount: { r: 969 } }, Collection: { acquireCount: { r: 969 } }, Mutex: { acquireCount: { r: 1 } } } storage:{ data: { bytesRead: 16805854, timeReadingMicros: 67676 } } protocol:op_msg 124ms
  • Unauthorized: not authorized on <db> to execute command { collStats: “<collection>”, verbose: true, lsid: { id: UUID(“<UUID>”) }, $clusterTime: { clusterTime: Timestamp(1688149535, 1486), signature: { hash: BinData(0, D5E8AB41724B30B7D96861F72AB25F4AC3E5B9D8), keyId: 7199120492454744961 } }, $db: “<db>” }

Why do I get this log message when I don’t fully use the collection and what does it mean?

2

collStats and getMore, especially for getMore, i’m not sure what automated operations can trigger getMore command.

Are you sure really no one is ever using that collection? How frequent do you see these two messages?

3

Hi, @Kobe_W
It’s aperiodic, but it’s printed almost once a month.
I confirmed that I don’t use it 100%.

4

then likely it’s safe to drop. getMore can be called by like find, which can exist in backup related tools.

collStats is for monitoring mostly.

5

@Kobe_W
What is this monitoring for?
There is no monitoring solutions