System properties
These system properties and environment variables can be set when you start your server allowing for the configuration of various settings.
How they work
Section titled “How they work”System properties are set when you start your server. For example, if you are using a .bat or a .sh file to start your server, you can add the system properties to
the file. For example:
java -Dvelocity.packet-decode-logging=true -jar velocity.jarWhere a -D is used to set a system property, and the system property is velocity.packet-decode-logging with a value of true.
Otherwise, just add them to the start command.
List of system properties
Section titled “List of system properties”auth.forceSecureProfiles
Section titled “auth.forceSecureProfiles”- default:
true - description: Overrides
force-key-authenticationfrom the config. If not set, it will be automatically set to the current config value.
velocity.natives-tmpdir
Section titled “velocity.natives-tmpdir”- default:
unset - description: Temporary directory for Velocity native files. (If set, it will also define
io.netty.native.workdir)
velocity.max-known-packs
Section titled “velocity.max-known-packs”- default:
64 - description: Limits known packs to the Vanilla default to prevent crashing Velocity.
velocity.max-packets-per-flush
Section titled “velocity.max-packets-per-flush”- default:
8192 - description: The max amount of packets before the queue is flushed automatically.
velocity.log-server-backpressure
Section titled “velocity.log-server-backpressure”- default:
false - description: Whether Velocity should log if the server connection is writable and thus if the player connection will be auto-read.
velocity.packet-decode-logging
Section titled “velocity.packet-decode-logging”- default:
false - description: Whether packet decoding errors should be logged extensively.
velocity.increased-compression-cap
Section titled “velocity.increased-compression-cap”- default:
false - description: Whether the maximum uncompressed packet size should be set to its maximum supported limit (128 MiB) instead of the Vanilla limit (8 MiB).
velocity.disable-native-transport
Section titled “velocity.disable-native-transport”- default:
false - description: Whether to disable Netty’s native transport methods like the io_uring support and Epoll. If set to true, Velocity will use Java’s NIO transport instead.
velocity.enable-iouring-transport
Section titled “velocity.enable-iouring-transport”- default:
false - description: Enables Netty’s io_uring transport when set to true. By default, Velocity only uses the Epoll (on Linux) and kqueue (on macOS) native transports. This property does not override the
velocity.disable-native-transportproperty.
velocity.natives-disabled
Section titled “velocity.natives-disabled”- default:
false - description: Whether native functionality for specific operating systems should be disabled.
velocity.strictErrorHandling
Section titled “velocity.strictErrorHandling”- default:
true - description: Whether the client should disconnect on packet errors. Temporarily added in MC 1.20.5 and removed in 1.21.2 to help modded servers transition to this change.
List of environment variables
Section titled “List of environment variables”VELOCITY_FORWARDING_SECRET
Section titled “VELOCITY_FORWARDING_SECRET”- default:
unset - description: Overrides the forwarding secret inside the
forwarding-secret-file.