Added documentation + detailed logging

README.md

@@ -1,6 +1,15 @@
 # Loadr
 
-A lightweight REST load testing tool with robust support for different request patterns, token auth, and performance reports.
+A lightweight REST load testing tool with flexible request patterns, token auth, and detailed performance metrics output.
+
+## Stack
+- Core: Pure Golang
+- Output: Console + CSV/TXT reporting
+- Pattern support: Sequential and probabilistic request patterns
+- Transport: Standard Go HTTP client
+
+## Requirements
+- Golang 1.22.0+
 
 ## Installation
 
@@ -11,58 +20,85 @@ go build
 ## Quick Start
 
 ```bash
-# Simple pattern: 5 POST requests
+# Simple pattern: 5 POST requests at 20 req/sec
 ./loadr -rate=20 -max=100 -url=http://api.example.com -pattern=5p
 
 # Mixed pattern: 1 POST followed by 5 GETs, repeating
 ./loadr -rate=20 -max=100 -url=http://api.example.com -pattern=1p5g
 
-# With authentication and request body
+# Probabilistic pattern: 20% POSTs, 80% GETs
+./loadr -rate=20 -max=100 -url=http://api.example.com -pattern=20%p80%g
+
+# With auth and request body
 ./loadr -rate=20 -max=100 -url=http://api.example.com -pattern=2p3g -json=./data.json -token=YourBearerToken
 ```
 
 ## Request Patterns
 
-The `-pattern` flag supports flexible request patterns:
+The `-pattern` flag supports three types of request patterns:
 
 ### Simple Patterns
 - `5p` : 5 POST requests
 - `3g` : 3 GET requests
+- Default is `1g` if no pattern specified
 
 ### Sequential Patterns
-- `1p5g` : 1 POST followed by 5 GETs
+- `1p5g` : 1 POST followed by 5 GETs, repeating
 - `2p3g` : 2 POSTs followed by 3 GETs
 - `3g2p` : 3 GETs followed by 2 POSTs
 
-### Probabalistic Patterns
-- `20%p80%g` : 20% POST and by 80% GETs
-
-### Pattern Rules
-- Numbers specify how many requests of each type
-- 'p' or 'P' specifies POST requests
-- 'g' or 'G' specifies GET requests
-- '%' indicates probabilistic requests
-- If no number is specified, 1 is assumed (e.g., "pg" = "1p1g")
-- Pattern repeats until max requests is reached
+### Probabilistic Patterns
+- `20%p80%g` : Random selection with 20% POST and 80% GET probability
+- Percentages must sum to 100
 
 ## Command Line Flags
 
-- `-rate`: Number of requests per second (default: 10)
-- `-max`: Maximum number of requests to send (default: 50)
-- `-url`: Target URL (default: "https://example.com")
-- `-pattern`: Request pattern (e.g., "5p", "1p5g", "3g2p", "10%p90%g")
-- `-json`: Path to JSON file for request body
-- `-token`: Bearer token for authorization
-- `-v`, `-version`: Print version information
+```bash
+-rate     Number of requests per second (default: 10)
+-max      Maximum number of requests to send (default: 50)
+-url      Target URL (default: "https://example.com")
+-pattern  Request pattern (e.g., "5p", "1p5g", "20%p80%g")
+-json     Path to JSON file for request body
+-token    Bearer token for authorization
+-v        Print version information
+```
 
-## Reports
+## Performance Metrics
 
-Test results are automatically:
-1. Displayed in the console
-2. Saved to `.reports/[timestamp].txt`
+Loadr generates two types of reports:
 
-Reports include:
-- Total requests sent and received
+### Summary Report (.reports/summary_[timestamp].txt)
+- Total requests sent/received
 - Average, maximum, and minimum latency
-- Requests per second (sent and received)
+- Requests/sec (target and actual)
+- Latency percentiles (p50, p95, p99)
 - Pattern information
+
+### Detailed CSV (.reports/detailed_metrics_[timestamp].csv)
+- Per-request timestamps
+- Individual request latencies
+- Status codes
+- Request types
+
+## Technical Details
+
+### Rate Limiting
+Loadr uses a time-based approach to approximate the target requests per second:
+
+1. Calculates ideal interval between requests: `interval = 1second / requestsPerSecond`
+2. Tracks next scheduled request time
+3. Uses sleep to maintain timing between requests
+4. Launches requests asynchronously to maintain timing accuracy
+
+### Request Execution
+- Uses a global HTTP client for connection reuse
+- Requests are executed concurrently using goroutines
+- Metrics are updated synchronously using mutex protection
+
+### Metrics Collection
+- Real-time tracking of request latencies
+- Thread-safe counters for requests and responses
+- Calculates percentiles from stored request durations
+- Support for detailed CSV export for external analysis
+
+Note: The actual request rate may vary slightly from the target rate due to system load and network conditions. The detailed CSV output can be used to analyze the actual timing distribution.