spark 1.9.9

spark is a performance profiler 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
    • 1.18
    • 1.19
    Source Code:
    sk89q, astei
    spark is a performance profiler 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.

Recent Updates

  1. 1.9.9
  2. 1.8.0
  3. 1.7.0

Recent Reviews

  1. TakenNone
    Version: 1.9.9
    very nice plugin. Super duper helpful!!!!!!!!!!! Definitely get this!!!!!!!!!! UwU
  2. Auxilor
    Version: 1.9.9
    11/10 - Absolutely the best, most useful piece of server software available today
  3. Ssomar
    Version: 1.9.9
    Thank you for your work, great resource ! .
  4. V-SPAN
    Version: 1.8.14
    The web interface in spark has a number of improvements over the standard WarmRoast one, in particular the ability to apply MCP mappings directly in the interface, without having to go and obtain+configure the mappings yourself. :)
  5. TeamBergerhealer
    Version: 1.8.6
    Been using spark for many many years. As a developer it is a great tool to find and fix bottlenecks, tick stutters and even to diagnose plugins server admins created themselves. While timings give people hints of something being wrong, spark answers what.
  6. RobinMC
    Version: 1.8.0
    Excellent plugin, essential to any vanilla or modded server. My most used features are the healthreport, tickmonitor and profiler.
  7. Tau
    Version: 1.8.0
    Awesome new viewer changes
  8. DawsonH
    Version: 1.7.2
    What an amazing profiler. Extremely easy to user and provides all the information you could ever possibly need to make your plugin more performant! I would appreciate a feature to automatically filter out sleep functions in the numbers, however.
  9. Adenosine1
    Version: 1.7.2
    Honestly one of if not the best profiling plugin available. Spark has been super helpful finding memory issues on my server network. It also works on bungeecord and is very helpful for finding issues that are limited to the proxy.
  10. Photon
    Version: 1.7.2
    Great for profiling plugins, especially if you develop your own and want to check for performance problems.