20170830_srecon17_2.4
20170830_srecon17_2.4
- Anycast is not loadbalancing
- 1 - Start the story
- 2 - What is AnyCast ?
- 3 - Catch ?
- 4 - Don’t believe in Magic
Anycast is not loadbalancing
1 - Start the story
How do you scale ?
* Start with 1 Server
* More servers
* Tell clients about new servers ?
2 - What is AnyCast ?
What
- Network magic
- Configure the same IP on multiple devices
- Let the “netwrk” decide wich server receive the request
Pros:
- Simple client config
- Simple horizontal scaling
- Low dependency
Good for:
- Staless app
- “Simple” HA
3 - Catch ?
NOT lbs
- no control where is the request going
- no way to “stop accepting new request” BUT “keep serving existing”
- no traffic shapping
Monitoring ?
- Probe are basics
- Not easy to know from wich server the issue comes from
- May fall in a case were no backend is the closest for the Anycast probe …
Failure modes
- By default, no check of pool member ships
- No nothion on Pool
4 - Don’t believe in Magic
Anycast is usefull
But
- it is load DISTRIBUTION