🚀 LogPulse CLI

A High-Performance, Memory-Efficient Log Analysis Tool built with Java Core.

LogPulse is a command-line interface (CLI) tool designed to ingest, parse, and analyze massive server log files. It uses a Stream-based architecture to process files larger than available RAM (e.g., analyzing a 10GB log file on a machine with 512MB RAM) without triggering OutOfMemoryError.

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⚡ Key Features

• Zero-Memory Ingestion: Uses java.nio.file.Files.lines() to process logs lazily (line-by-line) rather than loading the entire file into memory.
• Robust Parsing: Regex-based parser with Optional handling to gracefully skip corrupt log lines without crashing.
• Statistical Analysis: Uses Java 8 Stream API (filter, map, groupingBy) to aggregate error counts and identify unstable services.
• State Persistence: Serializes analysis results into binary .ser files using ObjectOutputStream for efficient storage and retrieval.
• CLI flexibility: Supports command-line arguments to filter by specific Log Levels (INFO, WARN, ERROR) or target specific files.

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🛠️ Technical Highlights (The "Why")

This project was built to demonstrate mastery of Java Core and JVM Memory Management.

Challenge	Solution
Memory Constraints	Instead of readAllLines() (which creates a huge List), I used a Stream<String> pipeline. This allows the JVM to Garbage Collect processed lines immediately.
Data Integrity	Custom LogParseException and Optional<LogEntry> ensure the pipeline is fault-tolerant against bad data.
Performance	O(N) complexity for a single pass through the file using Functional Programming concepts.

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🚀 Getting Started

Prerequisites

• Java Development Kit (JDK) 8 or higher.

1. Generate Dummy Data

Navigate to the src directory Create a server.log file (default is 2 million lines, ~120MB) to test the performance

java service/LogGenerator.java

2. Run the Analyzer

java Main.java

Run with Custom Arguments

# Analyze WARN logs
java Main.java --level WARN

# Analyze a specific file
java Main.java logs/backup.log --level INFO

The "Stress Test" (Proof of Concept)

To prove the memory efficiency, run the application with a restricted Heap size of 64MB against a 100MB+ log file.

java -Xmx64m Main.java

👤 Author

Sujal Birari Core Java Project focusing on High-Performance I/O and Functional Programming.