Node Monitoring Metrics
- In performance testing, comprehensive monitoring of both the testing nodes and target nodes' resource usage is crucial.
- It not only helps accurately identify system bottlenecks and optimize resource allocation but also enhances the credibility of test results.
- This guide will help you master the core monitoring metrics provided by AngusTester and their application scenarios.
CPU Metrics
Evaluate system CPU usage to identify computational bottlenecks and optimize resource allocation.
| Metric Name | Parameter | Description | Key Purpose | Calculation Formula |
|---|---|---|---|---|
| Idle Rate | idle | Percentage of CPU idle time | Reflects CPU idle state | (Idle time/Total time)×100% |
| System Usage | sys | % time spent on system tasks | Evaluates OS overhead | (System time/Total time)×100% |
| User Usage | user | % time spent on user processes | Assesses app CPU usage | (User time/Total time)×100% |
| Wait Rate | wait_ | % time waiting for I/O | Identifies I/O bottlenecks | (Wait time/Total time)×100% |
| Other Usage | other | % time spent on other tasks | Evaluates additional load | (Other time/Total time)×100% |
| Total Usage | total | Overall CPU utilization | Assesses total CPU load | 100% - Idle Rate |
💡 Analysis Tip: When user usage consistently >70%, indicates potential application bottlenecks; wait rate >20% suggests I/O system performance issues.
Memory Metrics
Evaluate system memory usage to identify bottlenecks and optimize allocation.
Physical Memory Metrics
| Metric Name | Parameter | Description | Key Purpose |
|---|---|---|---|
| Free Memory | free | Unused physical memory | Assess available memory |
| Used Memory | used | Used physical memory | Evaluate memory usage |
| Free Memory % | freePercent | % of free physical memory | Quick memory adequacy |
| Used Memory % | usedPercent | % of used physical memory | Assess memory pressure |
Virtual Memory (Swap) Metrics
| Metric Name | Parameter | Description | Key Purpose |
|---|---|---|---|
| Free Swap | swapFree | Unused swap space | Virtual memory reserve |
| Used Swap | swapUsed | Used swap space | Virtual memory usage |
Total Memory (Physical+Virtual) Metrics
| Metric Name | Parameter | Description | Key Purpose |
|---|---|---|---|
| Actual Free Memory | actualFree | Total free physical+swap memory | Overall available memory |
| Actual Used Memory | actualUsed | Total used physical+swap memory | Overall memory usage |
| Actual Free Memory % | actualFreePercent | % of total free memory | Quick adequacy check |
| Actual Used Memory % | actualUsedPercent | % of total used memory | Overall memory pressure |
⚠️ Critical Threshold: When physical memory usage >80% with growing swap usage, indicates memory bottleneck requiring optimization or expansion.
Filesystem Metrics
Monitor storage space usage for capacity planning and preventing storage bottlenecks.
| Metric Name | Parameter | Description | Key Purpose | Calculation Formula |
|---|---|---|---|---|
| Free Space | free | Unused filesystem space | Available capacity | - |
| Used Space | used | Used filesystem space | Storage utilization | - |
| Available Space | avail | Actually available space | Practical capacity | - |
| Usage % | usedPercent | % of used filesystem space | Storage pressure | (Used space/Total)×100% |
📌 Configuration Note: AngusTester by default monitors the filesystem where the agent resides.
Disk I/O Metrics
Evaluate storage device performance and identify I/O bottlenecks.
| Metric Name | Parameter | Description | Key Purpose | Calculation Formula |
|---|---|---|---|---|
| Total Operations | total | Total disk read/write ops | Overall I/O load | Read ops + Write ops |
| Read Rate | readsRate | Read ops per second | Read performance | Read ops/Sampling interval |
| Write Rate | writesRate | Write ops per second | Write performance | Write ops/Sampling interval |
| Read Throughput | readBytesRate | Bytes read per second | Read bandwidth | Read bytes/Sampling interval |
| Write Throughput | writeBytesRate | Bytes written per second | Write bandwidth | Write bytes/Sampling interval |
💡 Performance Analysis: When read/write rates approach disk max IOPS, indicates potential disk bottleneck.
Network Metrics
Evaluate network performance and bandwidth usage to identify bottlenecks.
| Metric Name | Parameter | Description | Key Purpose | Calculation Formula |
|---|---|---|---|---|
| Received Bytes | rxBytes | Total bytes received | Inbound traffic | - |
| Receive Rate | rxBytesRate | Bytes received per second | Receive performance | Byte delta/Sampling interval |
| Receive Errors | rxErrors | Total receive errors | Network quality | - |
| Transmitted Bytes | txBytes | Total bytes sent | Outbound traffic | - |
| Transmit Rate | txBytesRate | Bytes sent per second | Send performance | Byte delta/Sampling interval |
Best Practices Guide
- Baseline Testing: Record metric baselines before formal load testing
- Correlation Analysis: When CPU wait rate increases, simultaneously check disk I/O metrics
- Alert Thresholds:
- Memory usage > 80%
- Disk usage > 85%
- Network error rate > 0.1%
- Capacity Planning: Reserve 30% headroom based on peak resource usage