spark 1.6.2

spark is a performance profiling plugin/mod for Minecraft clients, servers and proxies.

  1. Luck
    Tested Minecraft Versions:
    • 1.8
    • 1.9
    • 1.10
    • 1.11
    • 1.12
    • 1.13
    • 1.14
    • 1.15
    • 1.16
    • 1.17
    Source Code:
    sk89q, astei
    spark is a performance profiling plugin/mod for Minecraft clients, servers and proxies.
    Useful Links
    What does it do?
    spark is made up of a number of components, each detailed separately below.
    • CPU Profiler: Diagnose performance issues.
    • Memory Inspection: Diagnose memory issues.
    • Server Health Reporting: Keep track of overall server health.

    ⚡ CPU Profiler
    spark's profiler can be used to diagnose performance issues: "lag", low tick rate, high CPU usage, etc.

    It is:
    • Lightweight - can be ran in production with minimal impact.
    • Easy to use - no configuration or setup necessary, just install the plugin/mod.
    • Quick to produce results - running for just ~30 seconds is enough to produce useful insights into problematic areas for performance.
    • Customisable - can be tuned to target specific threads, sample at a specific interval, record only "laggy" periods, etc
    • Highly readable - simple tree structure lends itself to easy analysis and interpretation. The viewer can also apply deobfuscation mappings.
    It works by sampling statistical data about the systems activity, and constructing a call graph based on this data. The call graph is then displayed in an online viewer for further analysis by the user.

    There are two different profiler engines:
    • Native AsyncGetCallTrace + perf_events - uses async-profiler (only available on Linux x86_64 systems)
    • Built-in Java ThreadMXBean - an improved version of the popular WarmRoast profiler by sk89q.

    ⚡ Memory Inspection

    spark includes a number of tools which are useful for diagnosing memory issues with a server.
    • Heap Summary - take & analyse a basic snapshot of the servers memory
      • A simple view of the JVM's heap, see memory usage and instance counts for each class
      • Not intended to be a full replacement of proper memory analysis tools. (see below)
    • Heap Dump - take a full (HPROF) snapshot of the servers memory
      • Dumps (& optionally compresses) a full snapshot of JVM's heap.
      • This snapshot can then be inspected using conventional analysis tools.
    • GC Monitoring - monitor garbage collection activity on the server
      • Allows the user to relate GC activity to game server hangs, and easily see how long they are taking & how much memory is being free'd.
      • Observe frequency/duration of young/old generation garbage collections to inform which GC tuning flags to use
    ⚡ Server Health Reporting
    spark can report a number of metrics summarising the servers overall health.

    These metrics include:
    • TPS - ticks per second, to a more accurate degree indicated by the /tps command
    • Tick Durations - how long each tick is taking (min, max and average)
    • CPU Usage - how much of the CPU is being used by the server process, and by the overall system
    • Memory Usage - how much memory is being used by the process
    • Disk Usage - how much disk space is free/being used by the system
    As well as providing tick rate averages, spark can also monitor individual ticks - sending a report whenever a single tick's duration exceeds a certain threshold. This can be used to identify trends and the nature of performance issues, relative to other system or game events.

    To install, just add the spark.jar file to your servers plugins directory.

    Information about how to use commands can be found in the docs.

    If you’d like help analysing a profiling report, or just want to chat, feel free to join us on Discord.

    There are a few small "guides" available in the docs, covering the following topics.
    ccorp2002, PilgrimViis, Tau and 32 others like this.

Recent Updates

  1. 1.6.2
  2. 1.6.0
  3. 1.5.0

Recent Reviews

  1. andrewkm
    Version: 1.6.2
    Perfect for detecting and going over server issues. As always, amazing stuff from an amazing developer. Thank you Luck!
  2. Tau
    Version: 1.6.2
    epic profiler!
    just great.
  3. lokka30
    Version: 1.6.1
    Using Spark to test LevelledMobs, Spark made it very easy for us to spot where the plugin was using the most resources, allowing us to promptly solve the issues.
  4. samueljonas245
    Version: 1.6.1
    excelent plugin, great job!

  5. WarnDangerous
    Version: 1.6.1
    The plugin is way more better than timings, it helped me soo much on optimising my server, it's absolutely awesome
  6. CabbageRoll_
    Version: 1.6.1
    I never used any profiler before and this took me just a few minutes to figure out how the stuff works, awesome
  7. omgmagic
    Version: 1.6.1
    Excellent plugin, keep work on it! 10/10..
    I recommend to all..
    Very nice work..
  8. JonRahm
    Version: 1.6.1
    Although I put 4 stars, the plugin is 100% recommended, I only suggest that it be added to be able to obtain information about what CPU the machine uses and the TPS instead of putting 5 seconds, 10 seconds, 1 minute ... putting more time, or at least to be able to configure it to the taste of each one, since the maximum is 15 minutes and you cannot see the performance that has been half an hour or 1 hour ago, I think the ideal would be 5 seconds, 1 minute, 15 minutes, 30 minutes and 1 hour.
  9. ImIllusion
    Version: 1.6.0
    This plugin is a perfect tool for generating heapdumps.

    A developer using a proper profiler along will this plugin will have an extremely smooth ride patching memory leaks and improving general performance.
  10. Jxyy
    Version: 1.6.0
    I LOVE this plugin. Also that "mister_someone" guy is rating 1 star because it doesn't work on his server only (he is probably on 1.17 or smth lmao)

    good plugin for removing lag (Really helped when I had 1 tps, it was because of bees and spark told me that it was using 98% CPU)