jvm.options

## JVM configuration

################################################################
## IMPORTANT: JVM heap size
################################################################
##
## You should always set the min and max JVM heap
## size to the same value. For example, to set
## the heap to 4 GB, set:
##
## -Xms4g
## -Xmx4g
##
## See https://opensearch.org/docs/opensearch/install/important-settings/
## for more information
##
################################################################

# Xms represents the initial size of total heap space
# Xmx represents the maximum size of total heap space

-Xms${heap.min}
-Xmx${heap.max}

################################################################
## Expert settings
################################################################
##
## All settings below this section are considered
## expert settings. Don't tamper with them unless
## you understand what you are doing
##
################################################################

## GC configuration
8-10:-XX:+UseConcMarkSweepGC
8-10:-XX:CMSInitiatingOccupancyFraction=75
8-10:-XX:+UseCMSInitiatingOccupancyOnly

## G1GC Configuration
# NOTE: G1GC is the default GC for all JDKs 11 and newer
11-:-XX:+UseG1GC
# See https://github.com/elastic/elasticsearch/pull/46169 for the history
# behind these settings, but the tl;dr is that default values can lead
# to situations where heap usage grows enough to trigger a circuit breaker
# before GC kicks in.
11-:-XX:G1ReservePercent=25
11-:-XX:InitiatingHeapOccupancyPercent=30

## JVM temporary directory
-Djava.io.tmpdir=${OPENSEARCH_TMPDIR}

## heap dumps

# generate a heap dump when an allocation from the Java heap fails
# heap dumps are created in the working directory of the JVM
-XX:+HeapDumpOnOutOfMemoryError

# specify an alternative path for heap dumps; ensure the directory exists and
# has sufficient space
${heap.dump.path}

# specify an alternative path for JVM fatal error logs
${error.file}

## JDK 8 GC logging
8:-XX:+PrintGCDetails
8:-XX:+PrintGCDateStamps
8:-XX:+PrintTenuringDistribution
8:-XX:+PrintGCApplicationStoppedTime
8:-Xloggc:${loggc}
8:-XX:+UseGCLogFileRotation
8:-XX:NumberOfGCLogFiles=32
8:-XX:GCLogFileSize=64m

# JDK 9+ GC logging
9-:-Xlog:gc*,gc+age=trace,safepoint:file=${loggc}:utctime,pid,tags:filecount=32,filesize=64m

# Explicitly allow security manager (https://bugs.openjdk.java.net/browse/JDK-8270380)
18-23:-Djava.security.manager=allow

# JDK 20+ Incubating Vector Module for SIMD optimizations;
# disabling may reduce performance on vector optimized lucene
20-:--add-modules=jdk.incubator.vector

# HDFS ForkJoinPool.common() support by SecurityManager
-Djava.util.concurrent.ForkJoinPool.common.threadFactory=org.opensearch.secure_sm.SecuredForkJoinWorkerThreadFactory

# See please https://bugs.openjdk.org/browse/JDK-8341127 (openjdk/jdk#21283)
23:-XX:CompileCommand=dontinline,java/lang/invoke/MethodHandle.setAsTypeCache
23:-XX:CompileCommand=dontinline,java/lang/invoke/MethodHandle.asTypeUncached

# It should be JDK-24 (but we cannot bring JDK-24 since Gradle does not support it yet)
21-:-javaagent:agent/opensearch-agent-3.0.0-SNAPSHOT.jar