- Release Notes and Announcements
- Product Introduction
- Purchase Guide
- Getting Started
- Operation Guide
- FAQs
- Overview
- Permissions
- Pod Startup Fails Because the Envoy Sidecar Is Unready
- Envoy Status Code 431 "Request Header Fields Too Large" Is Returned
- Envoy Converts Headers to Lowercase
- Headless Service-related FAQs
- Istio-init Crashes
- VirtualService Does Not Take Effect
- Inappropriate VirtualService Route Matching Order
- Failed to Access an Ingress Gateway from the Public Network
- Parsing Fails After Smart DNS Is Enabled
- Locality Load Balancing Does Not Take Effect
- Client Status Code 426 "Upgrade Required" Is Returned
- Sidecars Are Not Automatically Injected
- Circuit Breaking Does Not Take Effect
- 404 Is Returned During Access to a StatefulSet's Pod IP Address
- Service Is Abnormal Due to a Retry Policy
- Incomplete Call Tracing Information
- TCM Policy
- Glossary
- Release Notes and Announcements
- Product Introduction
- Purchase Guide
- Getting Started
- Operation Guide
- FAQs
- Overview
- Permissions
- Pod Startup Fails Because the Envoy Sidecar Is Unready
- Envoy Status Code 431 "Request Header Fields Too Large" Is Returned
- Envoy Converts Headers to Lowercase
- Headless Service-related FAQs
- Istio-init Crashes
- VirtualService Does Not Take Effect
- Inappropriate VirtualService Route Matching Order
- Failed to Access an Ingress Gateway from the Public Network
- Parsing Fails After Smart DNS Is Enabled
- Locality Load Balancing Does Not Take Effect
- Client Status Code 426 "Upgrade Required" Is Returned
- Sidecars Are Not Automatically Injected
- Circuit Breaking Does Not Take Effect
- 404 Is Returned During Access to a StatefulSet's Pod IP Address
- Service Is Abnormal Due to a Retry Policy
- Incomplete Call Tracing Information
- TCM Policy
- Glossary
Client Status Code 426 "Upgrade Required" Is Returned
Last updated: 2023-12-26 15:28:29
Istio uses Envoy as the data plane to forward HTTP requests, and Envoy requires HTTP/1.1 or HTTP/2 by default.
426 Upgrade Required is returned when a client uses HTTP/1.0.Common nginx Scenario
If nginx is used for
proxy_pass reverse proxy, it uses HTTP/1.0 by default. You can explicitly set proxy_http_version to 1.1.upstream http_backend {server 127.0.0.1:8080;keepalive 16;}server {...location /http/ {proxy_pass http://http_backend;proxy_http_version 1.1;proxy_set_header Connection "";...}}
Stress Test Scenario
During ab stress test, HTTP/1.0 requests will be sent, and Envoy will always return
426 Upgrade Required but not forward them. Therefore, the stress test result will not be accurate. You can use other stress test tools, such as wrk.Enable Istio to Support HTTP/1.0
Some SDKs or frameworks may use the HTTP/1.0 protocol. For example, they use HTTP/1.0 to pull configuration information from the resource center/configuration center. If you want your service to run on Istio without modifying code, you can modify the istiod configuration by adding the
PILOT_HTTP10: 1 environment variable to enable HTTP/1.0.
Yes
No
Was this page helpful?