my /etc/elasticsearch/jvm.options is :
## 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://www.elastic.co/guide/en/elasticsearch/reference/current/heap-size.html
## for more information
##
################################################################
# Xms represents the initial size of total heap space
# Xmx represents the maximum size of total heap space
-Xms16g
-Xmx16g
################################################################
## 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
#-XX:+UseConcMarkSweepGC
#-XX:CMSInitiatingOccupancyFraction=75
#-XX:+UseCMSInitiatingOccupancyOnly
8-13:-XX:+UseConcMarkSweepGC
8-13:-XX:CMSInitiatingOccupancyFraction=75
8-13:-XX:+UseCMSInitiatingOccupancyOnly
## G1GC Configuration
# NOTE: G1GC is only supported on JDK version 10 or later.
# To use G1GC uncomment the lines below.
# 10-:-XX:-UseConcMarkSweepGC
# 10-:-XX:-UseCMSInitiatingOccupancyOnly
# 10-:-XX:+UseG1GC
# 10-:-XX:G1ReservePercent=25
# 10-:-XX:InitiatingHeapOccupancyPercent=30
## DNS cache policy
# cache ttl in seconds for positive DNS lookups noting that this overrides the
# JDK security property networkaddress.cache.ttl; set to -1 to cache forever
-Des.networkaddress.cache.ttl=60
# cache ttl in seconds for negative DNS lookups noting that this overrides the
# JDK security property networkaddress.cache.negative ttl; set to -1 to cache
# forever
-Des.networkaddress.cache.negative.ttl=10
## optimizations
# pre-touch memory pages used by the JVM during initialization
-XX:+AlwaysPreTouch
## basic
# explicitly set the stack size
-Xss1m
# set to headless, just in case
-Djava.awt.headless=true
# ensure UTF-8 encoding by default (e.g. filenames)
-Dfile.encoding=UTF-8
# use our provided JNA always versus the system one
-Djna.nosys=true
# turn off a JDK optimization that throws away stack traces for common
# exceptions because stack traces are important for debugging
-XX:-OmitStackTraceInFastThrow
# flags to configure Netty
-Dio.netty.noUnsafe=true
-Dio.netty.noKeySetOptimization=true
-Dio.netty.recycler.maxCapacityPerThread=0
-Dio.netty.allocator.numDirectArenas=0
# log4j 2
-Dlog4j.shutdownHookEnabled=false
-Dlog4j2.disable.jmx=true
-Djava.io.tmpdir=${ES_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
-XX:HeapDumpPath=/var/lib/elasticsearch
# specify an alternative path for JVM fatal error logs
-XX:ErrorFile=/var/log/elasticsearch/hs_err_pid%p.log
## JDK 8 GC logging
8:-XX:+PrintGCDetails
8:-XX:+PrintGCDateStamps
8:-XX:+PrintTenuringDistribution
8:-XX:+PrintGCApplicationStoppedTime
8:-Xloggc:/var/log/elasticsearch/gc.log
8:-XX:+UseGCLogFileRotation
8:-XX:NumberOfGCLogFiles=32
8:-XX:GCLogFileSize=64m
# JDK 9+ GC logging
9-:-Xlog:gc*,gc+age=trace,safepoint:file=/var/log/elasticsearch/gc.log:utctime,pid,tags:filecount=32,filesize=64m
# due to internationalization enhancements in JDK 9 Elasticsearch need to set the provider to COMPAT otherwise
# time/date parsing will break in an incompatible way for some date patterns and locals
9-:-Djava.locale.providers=COMPAT
but when i run smem:
PID User Command Swap USS PSS RSS
5781 elasticsearch /usr/share/elasticsearch/mo 0 6252 6333 8044
54110 root /lib/systemd/systemd-journa 0 26184 31892 39132
1054 user java -Xmx512M -Xms512M -ser 0 199072 200351 209832
43041 kibana /usr/share/kibana/bin/../no 0 250296 250497 252616
22054 logstash /usr/bin/java -Xms1g -Xmx1g 0 676772 679179 694364
37635 user java -Xmx1G -Xms1G -server 0 895996 897323 907332
37767 root /usr/bin/java -Xms1g -Xmx1g 0 997132 999649 1015288
9764 root /usr/lib/jvm/java-8-oracle/ 0 1590800 1592193 1602372
61930 root /usr/bin/java -Xms1g -Xmx1g 0 1604516 1607022 1622600
51066 root /usr/bin/java -Xms1g -Xmx1g 0 1741792 1744290 1759828
37897 root /usr/bin/java -Xms1g -Xmx1g 0 2101580 2104112 2119796
2458 elasticsearch /usr/share/elasticsearch/jd 0 28923468 28923772 28926408
2458 elasticsearch /usr/share/elasticsearch/jd 0 28923468 28923772 28926408
this line means 29GB of RAM! why? what is elasticsearch/jd ?