ModsFinder

FullStack Watchdog

by TelepathicGrunt

When the server watchdog kills a frozen server thread, FullStack Watchdog changes the crash report so it lists the code running on every thread.

FabricForgeNeoForgeServer-side onlyMIT LicenseOpen source1.16.5 – 1.21.1

What it does

The mod targets crashes where a thread locks up and the server thread stays stuck until the watchdog ends the process because a tick ran too long. Normally the crash report gives little to go on about which modded code or mixin caused the lock. With this mod installed, the report lists the code that was running for all threads at that moment, which may point to the source of a deadlock. It does not fix every deadlock, and the extra information may only narrow down a few cases.

The mod runs only on the server, where the watchdog system operates. Players can keep it installed on their clients, but it does nothing there, and clients without it can still connect. Server owners can also ship it inside a modpack. It requires Fabric API on Fabric. Files are published for Fabric, Forge and NeoForge, covering game versions 1.16.5 – 1.21.1, and the code is open source under the MIT License.

Key features

  1. Full thread dumps

    Watchdog crash reports include the code executing on every thread, not only the stuck server thread.

  2. Server-only operation

    The changes take effect only on dedicated servers, where the watchdog runs, and leave client gameplay untouched.

  3. Deadlock diagnosis aid

    The added stack detail can help identify which modded code or mixin caused an off-thread lock.

  4. Before and after examples

    The project page shows how a crash report looks without and with the mod installed.

Compatibility

Latest build for each game version and loader.

1.21.x2 of 2 versions with builds
1.21.11.0.1+1.19.2-fabricNot availableNot available
1.211.0.1+1.19.2-fabricNot availableNot available
1.20.x7 of 7 versions with builds
1.20.61.0.1+1.19.2-fabricNot availableNot available
1.20.51.0.1+1.19.2-fabricNot availableNot available
1.20.41.0.1+1.19.2-fabricNot available1.1.0+1.20.2-neoforge
1.20.31.0.1+1.19.2-fabricNot available1.1.0+1.20.2-neoforge
1.20.21.0.1+1.19.2-fabricNot available1.1.0+1.20.2-neoforge
1.20.11.0.1+1.19.2-fabric1.0.1+1.19.2-forge1.0.1+1.19.2-forge
1.201.0.1+1.19.2-fabric1.0.1+1.19.2-forge1.0.1+1.19.2-forge
1.19.x5 of 5 versions with builds
1.19.41.0.1+1.19.2-fabric1.0.1+1.19.2-forge1.0.1+1.19.2-forge
1.19.31.0.1+1.19.2-fabric1.0.1+1.19.2-forge1.0.1+1.19.2-forge
1.19.21.0.1+1.19.2-fabric1.0.1+1.19.2-forge1.0.1+1.19.2-forge
1.19.11.0.1+1.19.2-fabric1.0.1+1.19.2-forge1.0.1+1.19.2-forge
1.191.0.1+1.19.2-fabric1.0.1+1.19.2-forge1.0.1+1.19.2-forge
1.18.x3 of 3 versions with builds
1.17.x1 of 1 version with builds
1.16.x1 of 1 version with builds
ReleaseBetaAlphaNot available

Only full game releases are shown. This mod publishes no snapshot builds.

Requirements

Dependencies declared by the latest file for each loader.

Required 1

Fabric APILightweight and modular API providing common hooks and intercompatibility measures utilized by mods using the Fabric toolchain.
Required

Use cases

Diagnosing frozen servers

A server operator who sees repeated watchdog crashes can read the expanded report to find the thread and code involved.

Modpack deployment

Modpack authors can include the mod, since it is open source and runs only on the server side.

Who it’s for: Server owners and modpack authors who run into watchdog crashes caused by thread lockups and want more detail in the crash report.

Questions

Does FullStack Watchdog need Fabric API?

Yes. Fabric API is a required dependency on the Fabric loader, and it must be installed alongside FullStack Watchdog.

Do players need to install FullStack Watchdog?

No. The mod is server-side only, so clients can keep it or leave it out and still connect to a server that runs it.

Is the mod still needed on NeoForge for newer Minecraft releases?

Not on those releases, because newer NeoForge builds already include the same change, so a separate install is not required there.

Is the mod still needed on newer Fabric releases?

Not on those releases, because recent Fabric API builds already include the same change, so a separate install is not required there.

In the catalog

FullStack Watchdog is one of 36,990 Utility mods on ModsFinder, and one of 25,772 Utility mods for Fabric. 32,366 mods support Minecraft 1.21.1.

Utility mods36,990Fabric modsMods for 1.21.132,366

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What the author says

This is a tiny server-sided mod that makes it so that the logs show more information when the Watchdog system on the server has killed the server due to being deadlocked or stuck so long. The crash report log will now show all of the code that was running at the time of the deadlocked server. In other words, the full…
TelepathicGrunt, on the Modrinth page

Official listing

Owner
TelepathicGrunt
Published
2023-04-13
Updated on Modrinth
2023-11-22
Facts verified
2026-10-15

Tags

Utility
Open on ModrinthCompare