container support not enabled due to required cgroup subsystems not found

[Bob Vandette]

> On Mar 15, 2018, at 8:55 AM, Baesken, Matthias <matthias.baesken at sap.com> wrote:
> 
>> Following subsystems are present in the docker container:
>> # ls /sys/fs/cgroup/
>> blkio  cpu  cpuacct  cpuacct,cpu  cpuset  devices  freezer  hugetlb
>> memory  net_cls  net_prio  net_prio,net_cls  perf_event  pids  systemd
>> 
>> As far as I understand, JVM is using only memory, cpu and cpuset
>> subsystems
> 
> Hi,  in  jdk10  
> 
> "cpu,cpuacct”
> 

His system has  “cpu” and “cpuacct” links so that shouldn’t be the issue.

Bob.


> 
> Is checked  as well , see
> 
> http://hg.openjdk.java.net/jdk/jdk10/file/b09e56145e11/src/hotspot/os/linux/osContainer_linux.cpp
> 
> ( but unfortunately  not  cpuacct,cpu  ).
> This might cause  the message  :
> 
>> [0.001s][debug][os,container] Required cgroup subsystems not found
> 
> 
> In  jdk11  both  "cpu,cpuacct"  and  "cpuacct,cpu"   are checked .
> Jdk11  has also  a bit better  logging , so I think it would tell  you what  subsystem  is  not found .
> Could you maybe   rerun  with jdk11  ?
> 
> 
> Thanks, Matthias
> 
> 
> 
>> -----Original Message-----
>> From: jdk-dev [mailto:jdk-dev-bounces at openjdk.java.net] On Behalf Of
>> ashutosh mehra
>> Sent: Donnerstag, 15. März 2018 11:52
>> To: jdk-dev at openjdk.java.net
>> Subject: container support not enabled due to required cgroup subsystems
>> not found
>> 
>> When I run  jdk-10+46 build in a docker container, I don't see MaxHeapSize
>> being adjusted based on container memory limit.
>> 
>> Command to run docker container with 2G memory, 2 CPUs:
>> $ docker run -m2g --memory-swap=2g --cpus=2 -it --rm -v
>> /home/ashu/data/builds/openjdk/jdk-10+46:/root/jdk-10 ubuntu:16.04
>> 
>> Once inside the container ran the following command:
>> 
>> # /root/jdk-10//bin/java -XX:+UnlockDiagnosticVMOptions
>> -XX:+PrintFlagsFinal -version | grep MaxHeapSize
>> 
>> Output:
>>   size_t MaxHeapSize                              = 2015363072
>>                   {product} {ergonomic}
>> openjdk version "10" 2018-03-20
>> OpenJDK Runtime Environment 18.3 (build 10+46)
>> OpenJDK 64-Bit Server VM 18.3 (build 10+46, mixed mode)
>> 
>> When I used -Xlog:os+container=trace option, I get following information:
>> 
>> # /root/jdk-10//bin/java "-Xlog:os+container=trace" -version
>> 
>> [0.001s][trace][os,container] OSContainer::init: Initializing Container
>> Support
>> [0.001s][debug][os,container] Required cgroup subsystems not found
>> openjdk version "10" 2018-03-20
>> OpenJDK Runtime Environment 18.3 (build 10+46)
>> OpenJDK 64-Bit Server VM 18.3 (build 10+46, mixed mode)
>> 
>> Following subsystems are present in the docker container:
>> # ls /sys/fs/cgroup/
>> blkio  cpu  cpuacct  cpuacct,cpu  cpuset  devices  freezer  hugetlb
>> memory  net_cls  net_prio  net_prio,net_cls  perf_event  pids  systemd
>> 
>> As far as I understand, JVM is using only memory, cpu and cpuset
>> subsystems
>> which are present in my system. Not sure why is it reporting "Required
>> cgroup subsystems not found".
>> 
>> Any idea what could be wrong here? Are there other debug options to figure
>> out what is going wrong?
>> 
>> Regards,
>> Ashutosh Mehra