# HighAvailabilityAndClustering

**Repository Path**: sps1998/high-availability-and-clustering

## Basic Information

- **Project Name**: HighAvailabilityAndClustering
- **Description**: Keepalived&LVS（IPVS）从0-1实现高可用与集群功能
- **Primary Language**: C
- **License**: MulanPSL-2.0
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2026-06-30
- **Last Updated**: 2026-07-09

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# Keepalived - High Availability & Clustering

A lightweight, pure C implementation of Keepalived's core functionality, including VRRP (Virtual Router Redundancy Protocol) and IPVS (IP Virtual Server) load balancing.

## Features

### ✅ VRRP Protocol Stack
- RFC 3768 VRRP Version 2 compliance
- Master-Backup election mechanism
- Virtual IP (VIP) management via RTNetlink
- State machine (INIT → BACKUP → MASTER)
- Advertisement timer with skew time calculation
- Preempt timer for priority-based failover

### ✅ IPVS Load Balancing
- Netlink Generic interface for kernel communication
- Fallback to ipvsadm command mode
- Support for multiple scheduling algorithms (rr, wrr, lc)
- Automatic kernel module loading
- Static compilation for universal deployment

### ✅ Event-Driven Architecture
- Epoll-based I/O multiplexing
- Min-heap timer management
- Unified event scheduler
- Signal handling

### ✅ Memory Management
- Custom memory allocation wrapper
- Memory leak detection
- Debug-friendly allocation tracking

## Project Architecture

```
Keepalived/
├── core/                    # Core entry point
│   └── main.c               # Main process entry
├── lib/                     # Base library modules
│   ├── memory.c             # Memory management
│   ├── log.c                # Log system
│   ├── netlink.c            # RTNetlink interface
│   ├── ipvs.c               # IPVS interface
│   ├── epoll.c              # Epoll wrapper
│   ├── timer.c              # Min-heap timer
│   └── scheduler.c          # Event scheduler
├── vrrp/                    # VRRP protocol module
│   ├── vrrp.c               # VRRP core implementation
│   └── vrrp.h               # VRRP data structures
├── check/                   # Health check module (TBD)
├── include/                 # Public header files
│   ├── types.h              # Core data structures
│   ├── list.h               # Linked list utilities
│   ├── memory.h             # Memory interface
│   ├── log.h                # Log interface
│   ├── netlink.h            # Netlink interface
│   ├── ipvs.h               # IPVS interface
│   ├── epoll.h              # Epoll interface
│   ├── timer.h              # Timer interface
│   └── scheduler.h          # Scheduler interface
├── tests/                   # Test programs
│   └── test_netlink_ipvs.c  # Netlink & IPVS tests
└── Makefile                 # Build configuration
```

## Build & Installation

### Requirements
- GCC 9.0+
- Linux kernel with IPVS support
- Root privileges for runtime

### Build
```bash
git clone https://gitee.com/sps1998/high-availability-and-clustering.git
cd high-availability-and-clustering
make clean && make
```

### Install
```bash
sudo make install
```

### Static Build
The project uses static compilation by default, enabling deployment on systems with different GLIBC versions.

## Usage

### Run
```bash
sudo ./keepalived
```

### Signal Handling
- `SIGINT` / `SIGTERM`: Graceful shutdown
- `SIGUSR1`: Dump memory statistics
- `SIGUSR2`: Check memory leaks

## Development Phases

| Phase | Status | Description |
|-------|--------|-------------|
| Phase 1 | ✅ | Project architecture, core data structures, basic modules |
| Phase 2 | ✅ | Epoll event-driven scheduler, IPVS Netlink interface optimization |
| Phase 3 | ✅ | VRRP protocol stack implementation |
| Phase 4 | ⏳ | Health check module |
| Phase 5 | ⏳ | Configuration file parsing, complete function integration |

## VRRP State Machine

```
INIT → BACKUP → MASTER
         ↑          │
         └──────────┘
```

### State Transitions
| Current State | Event | Target State |
|---------------|-------|--------------|
| INIT | INIT / INTERFACE_UP | BACKUP |
| BACKUP | ADVERT_TIMER_EXPIRED | MASTER |
| BACKUP | RECEIVE_ADVERT (higher priority) | BACKUP |
| BACKUP | INTERFACE_DOWN | INIT |
| MASTER | RECEIVE_ADVERT (higher priority) | BACKUP |
| MASTER | INTERFACE_DOWN | INIT |

## License

This project is licensed under the MIT License - see the LICENSE file for details.

## References

- [RFC 3768 - Virtual Router Redundancy Protocol](https://tools.ietf.org/html/rfc3768)
- [Keepalived Official Documentation](https://keepalived.readthedocs.io/)
- [Linux IPVS Documentation](https://www.linuxvirtualserver.org/docs/)

## Contributing

Contributions are welcome! Please feel free to submit issues and pull requests.