HTTP/3 Support Issues

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Enabling HTTP/3 support in HyperBEAM can present unique challenges, particularly around configuration and runtime errors. This article delves into common issues encountered when attempting to run HyperBEAM with HTTP/3, providing detailed insights and potential solutions. Understanding these challenges is crucial for developers aiming to leverage the performance benefits of HTTP/3 in their applications. Let’s explore the problems and how to address them effectively.

Problem Description

When attempting to run HyperBEAM with HTTP/3 support, you might encounter several configuration and runtime errors that can prevent the server from starting successfully. These issues often stem from missing dependencies, incorrect configurations, or underlying problems with the TLS setup. Identifying these issues early is key to ensuring a smooth deployment process.

Environment

To provide context, the following environment was used when encountering these issues:

  • Branch: edge
  • Build Profile: http3
  • Platform: Linux
  • Erlang/OTP: 27.3

These environmental factors play a crucial role in the behavior of HTTP/3 support within HyperBEAM. Variations in these configurations can lead to different outcomes, highlighting the importance of a consistent and well-documented setup.

Issues Encountered

1. Missing quicer.app Dependency

One of the initial hurdles you might face is a missing dependency on quicer.app. This dependency is essential for HTTP/3 functionality, as QUIC (Quick UDP Internet Connections) is the underlying protocol for HTTP/3. The error message typically looks like this:

{badmatch,{error,{quicer,{"no such file or directory","quicer.app"}}}}

This error indicates that the quicer application is not found in the expected location. The quicer application is a crucial component for handling the QUIC protocol, which HTTP/3 relies on for its transport layer. Without it, the server cannot establish HTTP/3 connections.

Temporary Fix:

A temporary workaround involves adding quicer to the relx configuration. This ensures that the quicer application is included in the build. However, this is not an ideal solution for production environments, as it can lead to unnecessary bloat by including the dependency in profiles where it’s not needed. Adding dependencies globally can increase the size of your application package and potentially introduce conflicts or performance issues in environments where HTTP/3 is not used.

To address this properly, the dependency should be managed conditionally, ensuring it’s only included when the http3 profile is active. This approach keeps the build lean and reduces the risk of unintended side effects. Configuration management tools or build scripts can be used to dynamically include or exclude dependencies based on the active profile, providing a more robust and maintainable solution.

2. TLS Configuration Error

After resolving the quicer dependency, you might encounter TLS configuration errors. These errors often manifest during the startup of the HTTP/3 server and can be tricky to diagnose without clear error messages. The initial error might look like this:

{{badmatch,{error,config_error,tls_error}},
 [{cowboy,'-start_quic/3-fun-3-',5,
 [{file,"/home/ubuntu/HyperBEAM/_build/default/lib/cowboy/src/cowboy.erl"},
 {line,96}]}]}

This error message points to a mismatch or misconfiguration in the TLS settings, which are crucial for securing HTTP/3 connections. TLS (Transport Layer Security) is the cryptographic protocol that provides secure communication over a network. In the context of HTTP/3, TLS is integral to the QUIC protocol, ensuring encrypted and authenticated connections.

Following this, the application might exit with a more descriptive error message, indicating a timeout during the startup of the HTTP/3 server:

=INFO REPORT==== 16-Jun-2025::14:10:29.337931 ===
 application: hb
 exited: {bad_return,
 {{hb_app,start,[normal,[]]},
 {'EXIT',
 {{badmatch,
 {error,
 {timeout,staring_http3_server,
 <<"Ws-ct6H1E8fezVzTXV84cMsIDwoyaHkzDTLqHWgS_kw">>}}},
 [{hb_http_server,new_server,1,
 [{file,"/home/ubuntu/HyperBEAM/src/hb_http_server.erl"},
 {line,198}]},
 {hb_http_server,start,1,
 [{file,"/home/ubuntu/HyperBEAM/src/hb_http_server.erl"},
 {line,111}]},
 {hb_app,start,2,
 [{file,"/home/ubuntu/HyperBEAM/src/hb_app.erl"},
 {line,19}]},
 {application_master,start_it_old,4,
 [{file,"application_master.erl"},{line,295}]}]}}}}
 type: permanent

This error indicates that the server failed to start the HTTP/3 listener within the expected timeframe, suggesting an issue with the TLS configuration or the underlying QUIC setup. The timeout often occurs because the server cannot establish a secure connection due to incorrect or missing TLS certificates or other configuration problems.

To resolve this, you should verify the TLS configuration settings, including the paths to the certificate and key files, the supported TLS versions, and any other relevant TLS parameters. Ensure that the certificates are valid and correctly configured for the domain or IP address the server is listening on. Additionally, check for any firewall rules or network configurations that might be interfering with the establishment of TLS connections.

3. QUIC Listen Failure

A more detailed error message might reveal that the QUIC listener failed to start due to a configuration error related to TLS. Debug output might show the QUIC start configuration and the subsequent failure:

QUIC start config: [{alpn,["h3"]},
 {peer_unidi_stream_count,3},
 {peer_bidi_stream_count,100},
 {certfile,"priv/cert.pem"},
 {keyfile,"priv/cert.key"}]
Starting quicer:listen on port 58732 with opts: [{alpn,["h3"]},
 {peer_unidi_stream_count,3},
 {peer_bidi_stream_count,100},
 {certfile,"priv/cert.pem"},
 {keyfile,"priv/cert.key"}]
quicer:listen failed: {error,config_error,tls_error}

This output clearly indicates that the quicer:listen function, which is responsible for starting the QUIC listener, failed with a TLS-related configuration error. The error message config_error,tls_error suggests that there is an issue with the TLS settings provided to the QUIC listener. This could be due to invalid or missing certificate files, incorrect file paths, or other TLS configuration issues.

The final error message confirms this issue, providing further context about the location of the error within the code:

=ERROR REPORT==== 16-Jun-2025::15:09:06.708758 ===
Error in process <0.846.0> on node hb@ns31528130 with exit value:
{{badmatch,{error,config_error,{error,config_error,tls_error}}},
 [{hb_http_server,'-start_http3/3-fun-1-',3,
 [{file,"/home/ubuntu/HyperBEAM/src/hb_http_server.erl"},
 {line,224}]}]}

This error message highlights that the failure occurred within the hb_http_server module, specifically in the function responsible for starting HTTP/3. The nested config_error and tls_error indicate that the problem lies within the TLS configuration passed to the QUIC listener. To resolve this, you should carefully review the TLS configuration, ensuring that all required files are present and valid, and that the settings are correctly applied.

Common causes for this error include:

  • Incorrect file paths: The paths to the certificate (cert.pem) and key (cert.key) files might be incorrect, causing the server to fail to load the necessary credentials.
  • Invalid certificates: The certificate file might be invalid or not match the key file, leading to TLS handshake failures.
  • Missing intermediate certificates: If the certificate requires intermediate certificates, they might be missing, causing TLS verification to fail.
  • Permissions issues: The server process might not have the necessary permissions to read the certificate and key files.

To troubleshoot this issue, you should first verify that the file paths to the certificate and key files are correct. Next, ensure that the certificate is valid and matches the key. You can use tools like openssl to verify the certificate and key:

openssl x509 -in priv/cert.pem -text -noout
openssl rsa -in priv/cert.key -check

These commands will help you inspect the certificate details and ensure that the key is valid. If the certificate requires intermediate certificates, make sure they are included in the certificate chain. Additionally, verify that the server process has the necessary permissions to read the certificate and key files. Correcting these issues should help resolve the QUIC listen failure and allow the HTTP/3 server to start successfully.

Impact on Development

The issues encountered can significantly impede the development process. As noted, this is blocking the development of a specific device (referenced as #317), underscoring the critical nature of resolving these problems. When HTTP/3 support is not functioning correctly, it can lead to delays in testing, deployment, and overall project timelines. Developers might spend considerable time troubleshooting configuration errors rather than focusing on feature development and optimization.

The impact extends beyond immediate delays. Unstable HTTP/3 support can lead to uncertainty about the application's performance and reliability in real-world scenarios. If developers cannot confidently rely on HTTP/3 for improved performance, they might need to revert to older protocols, sacrificing the benefits of HTTP/3.

To mitigate these impacts, it's essential to prioritize the resolution of HTTP/3 support issues. This includes thorough testing, detailed documentation, and active community support. Clear communication about the status of HTTP/3 support and any known issues can also help manage expectations and prevent further delays.

Questions

To gain clarity and move forward, several questions need to be addressed:

  1. Is HTTP/3 support fully implemented and ready for use?
  2. Is there a specific branch where HTTP/3 functionality is working?
  3. Are there additional configuration steps or dependencies required for HTTP/3 that aren't documented?

These questions are crucial for understanding the current state of HTTP/3 support in HyperBEAM. Knowing whether HTTP/3 is fully implemented helps developers gauge its readiness for production use. Identifying specific branches with working HTTP/3 functionality can provide a stable environment for development and testing. Finally, understanding any undocumented configuration steps or dependencies is essential for avoiding common pitfalls and ensuring a successful deployment.

Addressing these questions will help streamline the development process and ensure that HyperBEAM can fully leverage the advantages of HTTP/3.