Log Begone — a mod for filtering log messages in Minecraft

Log Begone — a mod for filtering log messages in Minecraft

Log Begone is a utility mod for Minecraft that removes specified lines from the console and from the latest.log file. The vanilla game writes all warnings to the log file, including repeated messages about missing structures, biomes, blocks, or items left over from content that was previously removed from a modpack. This mod hides such lines, so the console and the log file remain readable during a session. It works both on the client and on a dedicated server — filtering operates separately for each environment, so no version synchronization between them is needed.

What tasks it is used for

The main scenario is modpacks from which individual mods or content have been removed. The remnants of such removals show up as thousands of identical warnings about a "missing entry" or an unknown registry identifier. Without a filter, while the world is loading the console is flooded with hundreds of such lines in a row, and the latest.log file grows to tens of megabytes during a single session.

Another typical case is messages about attempts by a vanilla client to connect to a modified server, or service lines about network channels. On a server with an open port, such messages appear with every scan by third-party clients and create background noise that makes it harder to spot real problems.

The third scenario is optimization. If the log is being written at thousands of lines per minute, disk write operations and message formatting take up a noticeable share of resources. By removing the expected noise from the filter list, these resources can be returned to the game thread — this is especially noticeable on servers with long uptime.

How filtering works

The mod intercepts log events even before they reach the standard output. If a message matches one of the specified criteria, it is not written to the console or to the file. There are no commands, graphical interface, or in-game notifications: everything is configured through a single text configuration file.

Two comparison modes are supported. The first is substring search: if any of the phrases from the list occurs in the message text, the line is cut off. This is enough for most repeated warnings, because their template usually contains a stable, unique part. The second mode is regular expressions: for messages where variable elements (numbers, identifiers, time) need to be accounted for, a pattern is specified in Java-regex syntax, and a match means the line is cut off.

Configuration

The file is named logbegone.json and is created automatically in the config folder of the game profile on first launch. In versions up to 1.0.1 the TOML format was used, but due to incompatibility with TOML packaging in NeoForge, the author switched the config to JSON via the GSON library.

File structure

By default, both lists contain the same lines — Disconnecting VANILLA connection attempt and Channels (with a trailing space, which is important for a correct match). These values remove messages that often appear on servers with an active modified network protocol.

Conclusion

Log Begone hides known-in-advance noise in Minecraft's log file using a list of phrases or regular expressions. It is not an optimization mod in the classic sense: world rendering and chunk loading remain the same, but an indirect gain in performance and log size under heavy spam is achieved because thousands of repeated lines simply are not written to disk.

It suits server administrators with a stable set of mods, modpack authors after removing content, as well as players who want to bring the log file down to a readable size for later diagnosing of real problems.