6 The HTTP Server - 6.27 Configuring the HTTP Server - 《Micronaut v2.1.0 Documentation》

6.27 Configuring the HTTP Server
- Using Native Transports

6.27 Configuring the HTTP Server

The HTTP server features a number of configuration options you may wish to tweak. They are defined in the NettyHttpServerConfiguration configuration class, which extends HttpServerConfiguration.

The following example shows how to tweak configuration options for the server via application.yml:

Configuring HTTP server settings

micronaut:
    server:
        maxRequestSize: 1MB
        host: localhost (1)
        netty:
           maxHeaderSize: 500KB (2)
           worker:
              threads: 8 (3)
           childOptions:
              autoRead: true (4)

1	By default Micronaut will bind to all the network interfaces. Use `localhost` to bind only to loopback network interface
2	Maximum size for headers
3	Number of netty worker threads
4	Auto read request body

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Table 1. Configuration Properties for NettyHttpServerConfiguration
Property	Type	Description
`micronaut.server.netty.child-options`	java.util.Map	Sets the Netty child worker options.
`micronaut.server.netty.options`	java.util.Map	Sets the channel options.
`micronaut.server.netty.max-initial-line-length`	int	Sets the maximum initial line length for the HTTP request. Default value (4096).
`micronaut.server.netty.max-header-size`	int	Sets the maximum size of any one header. Default value (8192).
`micronaut.server.netty.max-chunk-size`	int	Sets the maximum size of any single request chunk. Default value (8192).
`micronaut.server.netty.chunked-supported`	boolean	Sets whether chunked transfer encoding is supported. Default value (true).
`micronaut.server.netty.validate-headers`	boolean	Sets whether to validate incoming headers. Default value (true).
`micronaut.server.netty.initial-buffer-size`	int	Sets the initial buffer size. Default value (128).
`micronaut.server.netty.log-level`	io.netty.handler.logging.LogLevel	Sets the Netty log level.
`micronaut.server.netty.compression-threshold`	int	Sets the minimum size of a request body must be in order to be compressed. Default value (1024).
`micronaut.server.netty.compression-level`	int	Sets the compression level (0-9). Default value (6).
`micronaut.server.netty.use-native-transport`	boolean	Sets whether to use netty’s native transport (epoll or kqueue) if available . Default value (false).
`micronaut.server.netty.fallback-protocol`	java.lang.String	Sets the fallback protocol to use when negotiating via ALPN.

Using Native Transports

The native Netty transports add features specific to a particular platform, generate less garbage, and generally improve performance when compared to the NIO based transport.

To enable native transports first add a necessarily dependency:

For macOS:

runtime("io.netty:netty-transport-native-kqueue:osx-x86_64")

<dependency>
    <groupId>io.netty</groupId>
    <artifactId>netty-transport-native-kqueue</artifactId>
    <scope>runtime</scope>
    <classifier>osx-x86_64</classifier>
</dependency>

For Linux:

runtime("io.netty:netty-transport-native-epoll:linux-x86_64")

<dependency>
    <groupId>io.netty</groupId>
    <artifactId>netty-transport-native-epoll</artifactId>
    <scope>runtime</scope>
    <classifier>linux-x86_64</classifier>
</dependency>

Then configure the default event loop group to prefer native transports:

Configuring The Default Event Loop to Prefer Native Transports

micronaut:
    netty:
        event-loops:
            default:
                prefer-native-transport: true