https://github.com/codepr/llb
Dead simple event-driven load-balancer
https://github.com/codepr/llb
epoll event-driven http load-balancer multithreading networking simple small-projects
Last synced: 9 days ago
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Dead simple event-driven load-balancer
- Host: GitHub
- URL: https://github.com/codepr/llb
- Owner: codepr
- License: bsd-2-clause
- Created: 2020-03-17T21:16:45.000Z (almost 6 years ago)
- Default Branch: master
- Last Pushed: 2024-12-12T17:22:50.000Z (about 1 year ago)
- Last Synced: 2024-12-12T18:28:45.918Z (about 1 year ago)
- Topics: epoll, event-driven, http, load-balancer, multithreading, networking, simple, small-projects
- Language: C
- Size: 139 KB
- Stars: 33
- Watchers: 4
- Forks: 7
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Changelog: changelog.sh
- License: LICENSE
Awesome Lists containing this project
README
llb
===
(**L**)ittle(**L**)oad(**B**)alancer, a dead simple event-driven load-balancer.
Supports Linux (and arguably OSX) through epoll and poll/select (kqueue on
BSD-like) as fallback, it uses an event-loop library borrowed from
[Sol](https://github.com/codepr/sol.git).
Written out of boredom/learning purpose (50/50) during self-isolation. Sure
thing there will be bugs and plenty of corner cases to be addressed.
Features:
- Logging
- Configuration file on disk
- Basic healthcheck for backends
- TLS encryption (to be refined)
- Daemon mode
- Multithread event-loop
- HTTP and TCP load-balancing
- Round-robin, weighted round-robin, hash-balancing, random-balancing,
leastconn, leasttraffic
- Pretty small (~2000 sloc) and little dependencies (openssl)
Next:
- Improvements on all previous points
## Build
**Dependencies**
- gcc
- make
- cmake
- OpenSSL (libssl-dev)
```sh
$ cmake . && make
```
## Quickstart
Backend servers at http://localhost:8080 and http://localhost:8081, balancing
strategy WEIGHTED-ROUND-ROBIN
```sh
$ ./llb -v -b http://localhost:8080:2,http://localhost:8081:4 -l weighted-round-robin
```
A simple configuration can be passed in with `-c` flag:
```sh
$ ./llb -c path/to/llb.conf
```
As of now the configuration is very small and self-explanatory, default path is
located to `/etc/llb/llb.conf`:
```sh
# llb configuration file, uncomment and edit desired configuration
# accepts http | tcp
mode http
# Load-balancing settings
# Frontends are the endpoint exposed as entry point for connecting clients
frontends 127.0.0.1:8789,127.0.0.1:8790,127.0.0.1:8791
# Backends is a pool of server to load-balance requests from clients
backends 127.0.0.1:6090,127.0.0.1:6090,127.0.0.1:6090
# Set round robin as balancing algorithm
# Other options available can be
# random-balancing | hash-balancing | leastconn | leasttraffic | weighted-round-robin
load_balancing round-robin
# Logging configuration
# Could be either DEBUG, INFO/INFORMATION, WARNING, ERROR
log_level DEBUG
log_path /tmp/llb.log
# TCP backlog, size of the complete connection queue
tcp_backlog 128
# TLS certs
#cafile certs/ca.crt
#certfile certs/alaptop.crt
#keyfile certs/alaptop.key
# TLS supported versions
#tls_protocols tlsv1,tlsv1_1,tlsv1_2,tlsv1_3
```
Executable accepts some simple arguments, in case of a configuration file
specified every setting is overridden by it.
- `-h` print an usage help
- `-v` enable verbose debug messages
- `-d` run in daemon mode
- `-c ` specify a configuration path, defaults to `/etc/llb/llb.conf`
- `-l ` specify a load-balancing algorithm to be
used. Choices are `round-robin`, `hash`, `random`, `leastconn`, `leasttraffic`
and `weighted-round-robin`
- `-m ` choose the run mode between `tcp` and `http`. Defaults to `http`
- `-b ,..` add backend machines with a
weight associated, it will be ignored for load-balancing algorithms other
than `weighted-round-robin`