We have a kubernetes cluster with ~100 nodes with istio and want to enable the Locality LoadBalancing feature. This will save us up to 70k USD/year because our interzone data traffic is too high.
I've followed the docs and setup the istio configmap like this:
...
meshNetworks: {}
localityLbSetting:
enabled: true
distribute:
- from: us-east-1/us-east-1a/*
to:
"us-east-1/us-east-1a/*": 100
- from: us-east-1/us-east-1b/*
to:
"us-east-1/us-east-1b/*": 100
...And then deployed 2 apps, one of them just responds with the zone where the node is deployed (we are using a VirtualService) and the another one just do the requests.
The requests that are coming from node in us-east-1a should only be replied by the nodes in the same zone, right?
But it's not happening.
We also tried to set this variable inside pilot pods:
PILOT_ENABLE_LOCALITY_LOAD_BALANCING
When I get logs from one pod that is deployed in zone "us-east-1a" it shows replies from both zones.
Istio Version: 1.2.8
Kubernetes Version: 1.14
Any help is appreciated! Thank you!
I'm afraid your configuration is invalid in case of 'Locality' weights between regions/zones in context of 'Locality Load Balancing' feature in 'distribute' mode.
The logs of your istio-pilot should give you a clue about it, in the form of warning similar to this one:
<timestamp> warn failed to read mesh configuration, using default: 1 error occurred:
* locality weight must not be in range [1, 100]I don't think you can find it documented anywhere in Istio documentation, but the logic behind the weights' validation can be found here.