GoTLB
GoTLB is a Go based TCP Load Balancer built for marathon apps.
Status: Alpha
Usage
Today we support only marathon based discovery and we would like to add support for other types of backend as well.
$ gotlb http://marathon.host:8080
Features
- RAW TCP Support
- Round Robin based LoadBalancingStrategy
- Marathon provider (more providers are welcome)
- Live updating of routing table (no downtime)
- Zero configuration (except for marathon host)
- Application specification in marathon is the source of truth. Configurations done via labels.
TODO
- TLS
- SNI + TLS
Why an another LB?
When you're doing micro-services there are number of load balancers available as choices like Traefik, LinkerD, HAProxy via marathon-lb or others, etc. But all of them support HTTP and some HTTP/2 and only one in that list support TCP - HAProxy. Unfortunately it still doesn't support hot reloading of the routes. We looked at things like fabio as well which recently added support for TCP. But that had an external dependency like Consul, which is something we don't have in our infrastructure. At Indix, we use application labels for configuring our apps. So the source of truth is always with the application's specification and not outside. Hence this is an attempt at solving the problem with the given constraints.
Also it was fun!
Required Labels
We use the following list of labels in the app specification to identify and configure the frontends
| Property | Description | Example |
|---|---|---|
| tlb.enabled | Controls if the load balancer for the app should be enabled or disabled. Defaults - false |
true |
| tlb.port | Expose the app through this port to the outside world. This is a mandatory label. If this property is not present even though tlb.enabled is set to true we'll not expose the app. |
11000 |
| tlb.portIndex | Ability to choose which port to be picked for load balancing. If you've configured 2 ports for your app, and you want to expose the app via the 2nd port via tlb.port to the outside world set this value to 1. This is 0 based index value. Default - 0 |
1 |
Contribute
If you've any feature requests or issues, please open a Github issue. We accept PRs. Fork away!