From cc88bc65e1aa1465ca7c9262c6d6f8349de4806f Mon Sep 17 00:00:00 2001 From: Aikar Date: Mon, 4 May 2020 01:14:10 -0400 Subject: [PATCH] Set cap on JDK per-thread native byte buffer cache See: https://www.evanjones.ca/java-bytebuffer-leak.html This is potentially a source of lots of native memory usage. We are clearly seeing native usage upwards to 1-4GB which doesn't make sense. Region File usage fixed in previous patch should of tecnically only been somewhat temporary until GC finally gets it some time later, but between all the various plugins doing IO on various threads, this hidden detail of the JDK could be keeping long lived large direct buffers in cache. Set system properly at server startup if not set already to help protect from this. --- ...-per-thread-native-byte-buffer-cache.patch | 31 +++++++++++++++++++ 1 file changed, 31 insertions(+) create mode 100644 Spigot-Server-Patches/Set-cap-on-JDK-per-thread-native-byte-buffer-cache.patch diff --git a/Spigot-Server-Patches/Set-cap-on-JDK-per-thread-native-byte-buffer-cache.patch b/Spigot-Server-Patches/Set-cap-on-JDK-per-thread-native-byte-buffer-cache.patch new file mode 100644 index 0000000000..6f5f14f5b9 --- /dev/null +++ b/Spigot-Server-Patches/Set-cap-on-JDK-per-thread-native-byte-buffer-cache.patch @@ -0,0 +1,31 @@ +From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 +From: Aikar +Date: Mon, 4 May 2020 01:08:56 -0400 +Subject: [PATCH] Set cap on JDK per-thread native byte buffer cache + +See: https://www.evanjones.ca/java-bytebuffer-leak.html + +This is potentially a source of lots of native memory usage. + +We are clearly seeing native usage upwards to 1-4GB which doesn't make sense. + +Region File usage fixed in previous patch should of tecnically only been somewhat +temporary until GC finally gets it some time later, but between all the various +plugins doing IO on various threads, this hidden detail of the JDK could be +keeping long lived large direct buffers in cache. + +Set system properly at server startup if not set already to help protect from this. + +diff --git a/src/main/java/org/bukkit/craftbukkit/Main.java b/src/main/java/org/bukkit/craftbukkit/Main.java +index 093dbeae27..93340e9470 100644 +--- a/src/main/java/org/bukkit/craftbukkit/Main.java ++++ b/src/main/java/org/bukkit/craftbukkit/Main.java +@@ -0,0 +0,0 @@ public class Main { + + public static void main(String[] args) { + // Todo: Installation script ++ if (System.getProperty("jdk.nio.maxCachedBufferSize") == null) System.setProperty("jdk.nio.maxCachedBufferSize", "262144"); // Paper - cap per-thread NIO cache size + OptionParser parser = new OptionParser() { + { + acceptsAll(asList("?", "help"), "Show the help"); +-- \ No newline at end of file