Spark Unforged

What this mod does Spark Unforged brings the current Spark profiler to Minecraft 1.12.2. The original Spark project moved on to newer game versions, leaving the 1.12.2 builds stuck on old code without async profiling or the newer quality-of-life features. This fork ports those improvements forward so older modpacks and servers can still use them. It runs on Forge, works on both client and server, and is licensed under GNU GPLv3. ## Who it's for If you run a 1.12.2 server or play a heavy 1.12.2 modpack and need to find why ticks are slow, this is the tool. Pack authors use it to debug load times. Server admins use it to catch lag spikes. Developers use it to inspect memory and CPU behavior without leaving the game. ## Main capabilities CPU profiling samples thread activity and builds a call graph you can open in the Spark web viewer. Two engines are available: the Java engine (ThreadMXBean) works everywhere, while the native async profiler only runs on Linux and macOS. A 30-second sample is usually enough to spot the hot paths. Memory inspection gives three tools. Heap Summary shows a quick class-level breakdown of the live heap. Heap Dump writes a full HPROF file you can load into VisualVM or Eclipse MAT. GC Monitoring logs young and old generation collections so you can correlate pauses with tick spikes. Server health reporting tracks TPS, per-tick min/max/average durations, process and system CPU, JVM memory, and disk space. You can set a threshold and get a report whenever a single tick exceeds it. Load profiling is the new feature unique to this fork. And it profiles the startup sequence - coremod, preinit, init, postinit, world load, server load - and can also capture memory allocation data when the async profiler is available. It's off by default; enable it in config/spark/config.json after the first run creates the file. Results save to config/spark/data for manual upload to the viewer. ## Compatibility caveats Only Forge on 1.12.2 is supported. The mod requires Mixin at runtime; most packs already include it via another mod, but if not you'll need MixinBootstrap or the Mixin 0.7-0.8 compatibility layer. Because 1.12.2 runs on Java 8, live profile viewing and the extra server metadata panel (datapack listing) are disabled. The command syntax matches the modern Spark wiki, so existing guides apply directly.