Monitoring Metrics for MongoDB
Last Updated At: 2025-10-21 09:10:00
Cloud Monitor provides the following dimensions of monitoring metrics for MongoDB:
Monitoring Metrics for the Replica Sets
| Metric Name |
Unit |
Metric Description |
| Cache dirty data percentage |
% |
Percentage of dirty data volume to total data volume in the cache |
| Cache utilization |
% |
Percentage of used cache space to total cache space |
| Disk utilization |
% |
- |
| Cache hit rate |
% |
Percentage of cache hits to total access times |
| Oplog retention time |
Hour |
- |
| Average primary/secondary node latency per unit of time |
s |
Average latency of primary/secondary nodes per unit of time |
Monitoring Metrics for Nodes
| Metric Name |
Unit |
Metric Description |
| CPU utilization |
% |
- |
| Memory utilization |
% |
- |
| Number of read requests in the waiting queue |
Count |
- |
| Number of write requests in the waiting queue |
Count |
- |
| Inbound network traffic |
MB/s |
Average inbound traffic per second |
| Outbound network traffic |
MB/s |
Average outbound traffic per second |
| Number of connections |
Count |
- |
| Node disk usage |
MB |
Disk space size used by a single node |
| WT engine's ActiveRead |
Count |
Number of active read operations in the WT engine |
| WT engine's ActiveWrite |
Count |
Number of active write operations in the WT engine |
| Number of data entries deleted after TTL is triggered |
Count |
- |
| Number of TTL running rounds |
Count |
Number of rounds of data cleanup operations triggered based on the TTL index |
Monitoring Metrics Instances
| Metric Name |
Unit |
Metric Description |
| Number of write requests |
Times |
Number of write requests initiated |
| Number of read requests |
Times |
Number of read requests initiated |
| Number of update requests |
Times |
Number of update requests initiated |
| Number of deletion requests |
Times |
Number of deletion requests initiated |
| Number of count requests |
Times |
Number of count requests initiated |
| Number of aggregation requests |
Times |
Number of aggregation requests initiated |
| Number of command requests |
Times |
Number of command requests initiated |
| Number of successful requests |
Times |
Number of requests that succeeded and received the expected response |
| Disk utilization |
% |
- |
| Number of requests with unit time latency (10 ms to 50 ms) |
Times |
Number of requests with latency between 10 ms and 50 ms |
| Number of requests with unit time latency (50 ms to 100 ms) |
Times |
Number of requests with latency between 50 ms and 100 ms |
| Number of requests with unit time latency (over 100 ms) |
Times |
Number of requests with latency over 100 ms |
| Connection utilization |
% |
- |
| Number of connections |
Count |
- |
Monitoring Metrics for Instances (Replica Set Instance for Versions Above MongoDB 4.0)
| Metric Name |
Unit |
Metric Description |
| Number of write requests |
Times |
- |
| Number of read requests |
Times |
- |
| Number of update requests |
Times |
- |
| Number of deletion requests |
Times |
- |
| Number of successful requests |
Times |
- |
| Disk utilization |
% |
- |
| Number of requests with unit time latency (10 ms to 50 ms) |
Times |
Number of requests with latency between 10 ms and 50 ms |
| Number of requests with unit time latency (50 ms to 100 ms) |
Times |
Number of requests with latency between 50 ms and 100 ms |
| Number of requests with unit time latency (over 100 ms) |
Times |
Number of requests with latency over 100 ms |
| Number of connections |
Count |
- |
| Connection percentage |
% |
- |
