User Data Download - freezes the server

Community Support
1

Description

I have bad experience with “User Data Download”
The MongoDB crashed several times during this operation

After that I set the settings and tried to download again:
Processing Frequency (Minutes): 2
Message Limit per Request: 1000

For several hours the CPU(2 core) was loaded at 100% and the chat itself was terribly slow.
more than 100% took the process: mongod --config=/var/snap/rocketchat-server/1556/mongod.conf --fork --syslog

There are a lot of messages in the logs - “parties.rocketchat_uploads.chunks”
Jul 19 15:58:02 vm-it-uc5-1 mongod: {“t”:{“$date”:“2023-07-19T15:58:02.236+03:00”},“s”:“I”, “c”:“COMMAND”, “id”:51803, “ctx”:“conn82”,“msg”:“Slow query”,“attr”:{“type”:“command”,“ns”:“parties.rocketchat_uploads.chunks”,“command”:{“find”:“rocketchat_uploads.chunks”,“filter”:{“files_id”:“5355gZGWu2AHHCpX6”},“sort”:{“n”:1},“limit”:0,“lsid”:{“id”:{“$uuid”:“753ac6c7-1596-4afa-bc63-c80edbd6ed2a”}},“$clusterTime”:{“clusterTime”:{“$timestamp”:{“t”:1689771458,“i”:1}},“signature”:{“hash”:{“$binary”:{“base64”:“AAAAAAAAAAAAAAAAAAAAAAAAAAA=”,“subType”:“0”}},“keyId”:0}},“$db”:“parties”},“planSummary”:“COLLSCAN”,“keysExamined”:0,“docsExamined”:17694,“hasSortStage”:true,“cursorExhausted”:true,“numYields”:390,“nreturned”:1,“queryHash”:“9FE7AF15”,“planCacheKey”:“9FE7AF15”,“reslen”:49891,“locks”:{“FeatureCompatibilityVersion”:{“acquireCount”:{“r”:391}},“ReplicationStateTransition”:{“acquireCount”:{“w”:391}},“Global”:{“acquireCount”:{“r”:391}},“Database”:{“acquireCount”:{“r”:391}},“Collection”:{“acquireCount”:{“r”:391}},“Mutex”:{“acquireCount”:{“r”:1}}},“storage”:{“data”:{“bytesRead”:5929125,“timeReadingMicros”:128816}},“protocol”:“op_msg”,“durationMillis”:15456}}

I stop process Troubleshoot->Disable Data Exporter Processor.

I think I have a database performance issue. Perhaps some indexes are missing or something else?
How can I diagnose and fix this error?

Server Setup Information

  • Version of Rocket.Chat Server: 5.4.10
  • Operating System: Debian 11.7
  • Deployment Method: snap
  • Number of Running Instances: 1
  • DB Replicaset Oplog: Enabled
  • NodeJS Version: 14.21.2 - x64
  • MongoDB Version: 4.4.15
  • Proxy: nginx

Any additional Information