Adaptive Throughput Timer Plugin

A JMeter plugin that dynamically adjusts thread count to achieve target throughput defined in a CSV file. It calculates 90th percentile latency per second and automatically increases or decreases thread count to meet specified TPS targets.

Features

• CSV-based Configuration: Define time and target TPS in a CSV file
• Dynamic Thread Adjustment: Automatically adjusts threads to meet TPS targets
• Percentile Monitoring: Calculates 90th percentile latency every second
• Configurable Thresholds: Control ramp-up/down steps, min/max threads, and adjustment intervals
• Real-time Metrics: Tracks current throughput vs target and latency metrics

Project Structure

adaptive-throughput-timer/
├── src/
│   ├── main/
│   │   ├── java/
│   │   │   └── com/adaptive/jmeter/plugins/
│   │   │       ├── AdaptiveTimerFromCSV.java          (Main timer component)
│   │   │       ├── AdaptiveTimerFromCSVGui.java       (GUI configuration)
│   │   │       ├── ThroughputMetrics.java             (Metrics tracking)
│   │   │       ├── CSVThroughputReader.java           (CSV file reading)
│   │   │       └── CSVThroughputEntry.java            (Data model)
│   │   └── resources/
│   └── test/
│       └── java/
│           └── com/adaptive/jmeter/plugins/
│               ├── AdaptiveTimerFromCSVTest.java
│               ├── CSVThroughputReaderTest.java
│               └── ThroughputMetricsTest.java
├── pom.xml
├── example-throughput.csv
└── README.md

CSV/TXT/Excel Format

CSV/TXT files use comma-separated values with format: stepcount,mm:ss,tps

Excel files (.xlsx, .xls) should have:

• Column A: stepcount (step number)
• Column B: time (mm:ss format)
• Column C: tps (transactions per second)

Supported file formats:

• .csv (Comma-Separated Values)
• .txt (Text file - same format as CSV)
• .xlsx (Excel 2007-2016)
• .xls (Excel 97-2003)

Example CSV/TXT:

# Load testing profile
# Format: stepcount,mm:ss,tps

1,00:30,100
2,01:00,250
3,02:00,500
4,03:00,1000
5,05:00,500

Example Excel File:

A         B        C
stepcount time     tps
1         00:30    100
2         01:00    250
3         02:00    500
4         03:00    1000
5         05:00    500

Configuration Options

Parameter	Default	Description
CSV File Path	-	Path to CSV/TXT/Excel file with time/TPS targets
Min Threads	1	Starting thread count (was called Initial Threads)
Max Threads	100	Maximum thread count
Adjustment Interval (ms)	5000	How often to check and adjust threads
Ramp Up Step	1	Threads to add per adjustment
Ramp Down Step	1	Threads to remove per adjustment
P90 Threshold (ms)	500	Maximum acceptable 90th percentile latency

Note: The plugin starts with Min Threads as the initial thread count (no separate Initial Threads parameter).

Building

mvn clean package

The compiled JAR will be located in target/adaptive-throughput-timer-1.0.0.jar

Installation

1. Build the plugin: mvn clean package
2. Copy JAR to JMeter: cp target/adaptive-throughput-timer-*.jar $JMETER_HOME/lib/ext/
3. Restart JMeter
4. The "Adaptive Timer From CSV" will appear in: Thread Group > Add > Timers

Thread Adjustment Algorithm

Every Adjustment Interval milliseconds, the plugin:

1. Calculates current throughput (samples/second)
2. Calculates 90th percentile response time
3. Compares current TPS vs target TPS
4. If deviation > 5%:
   • Increase threads if current TPS < target (ramp up)
   • Decrease threads if current TPS >> target AND P90 latency is acceptable (ramp down)
5. Resets metrics for next window

Usage Example

1. Create a CSV file throughput-profile.csv:

   00:30,100
   01:00,500
   02:00,1000
   05:00,500

2. In JMeter:

   • Add Thread Group
   • Add "Adaptive Timer From CSV" to the thread group
   • Configure CSV file path
   • Set initial threads and min/max ranges
   • Run test

Components

AdaptiveTimerFromCSV

Main timer component that implements JMeter's Timer interface. Manages thread adjustment logic and metrics collection.

ThroughputMetrics

Tracks response times in a sliding window and calculates percentiles, throughput, and error rates.

CSVThroughputReader

Reads and parses CSV files containing time/TPS definitions.

AdaptiveTimerFromCSVGui

Swing GUI component for configuring the timer in JMeter's UI.

Testing

Run tests:

mvn test

Test coverage includes:

• CSV file parsing
• Percentile calculations
• Thread adjustment logic
• Property management

License

Apache License 2.0