tencent cloud

Overview

This document describes how to restrict the Pod bandwidth in TKE. Currently, TKE does not support Pod speed restriction; however, you can modify the CNI plugin to achieve it based on your actual scenario.

Notes

• TKE supports using the bandwidth plugin of the community to restrict the network speed. Currently, it can be used in GlobalRouter mode and VPC-CNI shared ENI mode.
• Currently, it is not supported for the VPC-CNI dedicated ENI mode.

Directions

Modifying CNI plugin

GlobalRouter mode

The GlobalRouter network mode is a routing policy for communication between the container network and VPC based on the global routing capabilities of the underlying VPC. It is suitable for common scenarios and seamlessly compatible with standard Kubernetes features. For more information, see GlobalRouter Mode.

1. Log in to the Pod node as instructed in Logging in to Linux Instance Using Standard Login Method.
2. Run the following command to view the configuration of tke-bridge-agent:

   kubectl edit daemonset tke-bridge-agent -n kube-system
   

Add args --bandwidth to enable the support for the bandwidth plugin.

VPC-CNI shared ENI mode

The VPC-CNI mode is container network capability implemented based on CNI and VPC ENI and is suitable for scenarios with high requirements for latency.
The open-source bandwidth plugin supports traffic shaping at the Pod entry and exit as well as bandwidth control. For more information, see VPC-CNI Mode.

1. Log in to the Pod node as instructed in Logging in to Linux Instance Using Standard Login Method.
2. Run the following command to view the configuration of tke-eni-agent:

   kubectl edit daemonset tke-eni-agent -n kube-system
   

Add args --bandwidth to enable the support for the bandwidth plugin.

Note：

You can enable this feature simply by adding the above parameters to tke-eni-agent and disable it by removing the parameters. Deployment, enablement, and disablement are supported, which take effect only for new Pods.

Specifying annotation in Pod

You can configure in the method provided by the community:

• Use the kubernetes.io/ingress-bandwidth annotation to specify the inbound bandwidth cap.
• Use the kubernetes.io/egress-bandwidth annotation to specify the outbound bandwidth cap.

Sample:

apiVersion: apps/v1
kind: Deployment
metadata:
 name: nginx
spec:
 replicas: 1
 selector:
   matchLabels:
     app: nginx
 template:
   metadata:
     labels:
       app: nginx
     annotations:
       kubernetes.io/ingress-bandwidth: 10M
       kubernetes.io/egress-bandwidth: 20M
   spec:
     containers:
     - name: nginx
       image: nginx

Configuration Verification

You can verify whether the configuration succeeds in the following two methods:

• Method 1: log in to the Pod node and run the following command to check whether the caps have been added:

  tc qdisc show
  

If a result similar to the following is returned, the caps have been added successfully:

qdisc tbf 1: dev vethc09123a1 root refcnt 2 rate 10Mbit burst 256Mb lat 25.0ms
qdisc ingress ffff: dev vethc09123a1 parent ffff:fff1 ----------------
qdisc tbf 1: dev 6116 root refcnt 2 rate 20Mbit burst 256Mb lat 25.0ms

• Method 2: run the following command to use iperf for testing:

  iperf -c <service IP> -p <service port> -i 1
  

If a result similar to the following is returned, the caps have been added successfully:

------------------------------------------------------------
Client connecting to 172.16.0.xxx, TCP port 80
TCP window size: 12.0 MByte (default)
------------------------------------------------------------
[  3] local 172.16.0.xxx port 41112 connected with 172.16.0.xx port 80
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0- 1.0 sec   257 MBytes  2.16 Gbits/sec
[  3]  1.0- 2.0 sec  1.18 MBytes  9.90 Mbits/sec
[  3]  2.0- 3.0 sec  1.18 MBytes  9.90 Mbits/sec
[  3]  3.0- 4.0 sec  1.18 MBytes  9.90 Mbits/sec
[  3]  4.0- 5.0 sec  1.18 MBytes  9.90 Mbits/sec
[  3]  5.0- 6.0 sec  1.12 MBytes  9.38 Mbits/sec
[  3]  6.0- 7.0 sec  1.18 MBytes  9.90 Mbits/sec
[  3]  7.0- 8.0 sec  1.18 MBytes  9.90 Mbits/sec
[  3]  8.0- 9.0 sec  1.18 MBytes  9.90 Mbits/sec
[  3]  9.0-10.0 sec  1.12 MBytes  9.38 Mbits/sec
[  3]  0.0-10.3 sec   268 MBytes   218 Mbits/se