Hi Team,
In our 5-node replica set, we’re noticing high memory usage by MongoDB on one of the secondary servers. The cache is configured with default settings, but the combined total of the cache and free heap doesn’t account for MongoDB’s total memory usage. The memory usage keeps increasing by about 12 GB over two days, exceeding the expected cache + free heap values.
We’ve upgraded from version 7.0.9 to 7.0.14, but the issue persists — the memory usage still doesn’t align with the cache configuration. All memory parameters have been tuned according to MongoDB documentation.
Mongo version: 7.0.14
OS: ubuntu 22.04.3 LTS (Jammy Jellyfish)
root@dbserver04-cds:/home/mydbops# free -h
total used free shared buff/cache available
Mem: 123Gi 65Gi 796Mi 1.0Mi 56Gi 56Gi
Swap: 49Gi 585Mi 49Gi
root@dbserver04-cds:/home/mydbops#
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
2916728 mongodb 20 0 64.9g 63.3g 36096 S 68.0 61.4 678:07.12 mongod
Any insights or assistance would be greatly appreciated.