We have used four different commands to capture the memory usage for the Springboot apps running in CF runtime including: jcmp, ps, cf app and pmap. However, everyone seems report different values. Do you know which one is accurate? Here are example outputs:

Running “cf apps” the memory usage is reported as 930.4M:

C:\Program Files\Cloud Foundry>cf app mtp-identities
Showing health and status for app mtp-identities in org stocf / space dev as admin...

name: mtp-identities
requested state: started
instances: 1/1
usage: 2G x 1 instances
routes: vdmml.17w21.sas.com/identities
last uploaded: Thu 27 Apr 19:01:05 EDT 2017
stack: cflinuxfs2
buildpack: java_buildpack

state since cpu memory disk details
#0 running 2017-04-27T23:02:13Z 0.2% 930.4M of 2G 186M of 2G


If I ssh into the container and run ‘ps’, the RSS size is reported as 939M:

vcap(a)dpgdg9915eg:~$ ps axo user,pid,cpu,rss,size,vsize,nlwp,cmd --sort -rss
USER PID CPU RSS SIZE VSZ NLWP CMD
vcap 13 - 962008 5909184 6023768 58 /home/vcap/app/.java-buildpack/open_jdk_jre/bin/java -Djava.io.tmpdir=/home/vcap/tmp -XX:OnOutOfMemoryError=/home/vcap/app/.java-buildpack/open_jdk_jre/bin/killjava.sh -Xmx384M -XX:MaxMetaspaceSize=128M -Xss256K -Xms384M -XX:MetaspaceSize=128M -javaagent:/home/vcap/app/lib/aspectjweaver-1.8.9.jar -Dserver.port=8080 -Djava.security.egd=file:/dev/./urandom -Dconsul.token=tobeusedfordemosonlyclnt -XX:NativeMemoryTracking=detail -verbose:class -XX:MaxDirectMemorySize=10M -XX:ReservedCodeCacheSize=240M -cp /home/vcap/app/. org.springframework.boot.loader.JarLauncher

While still in the container, running pmap for the process, the RSS is reported as 944M, and the “dirty” column reports 921M:
Address Kbytes RSS Dirty Mode Mapping
…
total kB 6030924 966196 942984

None of this looks close to what is reported via the NMT (jcmp) totals though (644M of committed):

2017-04-28T12:28:03.81-0400 [APP/0] OUT Total: reserved=1889246KB +84548KB, committed=659678KB +137612KB