Sporadically my docker container gets 'orphaned' - docker

Question

My docker container builds a software product which takes more or less a couple of hours.
Most times, it runs fine. However, sometimes it gets 'orphaned' towards the end of execution.
By 'orphaned,' I mean:
1. 'docker ps' reports the container properly.
2. 'docker inspect' reports normally too.
3. however, 'docker exec' returns an error, saying "connect: connection refused": unknown"
[jenkins#aga-slave-jenkins-lnx1 ~]$ docker exec -it 6f667c2ca550 bash
connection error: desc = "transport: dial unix /var/run/docker/containerd/docker-containerd.sock: connect: connection refused": unknown
Once orphaned, it wouldn't go to the next step or exit; it's just hanging there forever.
So my only option is to restart the docker daemon in order to end this misery.
Here is my dockerfile after non-crucial parts omitted for brevity.
RUN svn update -q --no-auth-cache --username $SVN_USER --password $SVN_PASSWORD $WORKSPACE/_Build && \
svn update -q --no-auth-cache --username $SVN_USER --password $SVN_PASSWORD $IVY_REPOSITORY && \
ant -f $WORKSPACE/_Build/_Checkout.xml checkoutLibraries $ANT_ARGUMENTS -Daga.component=ui && \
ant -f $WORKSPACE/_Build/_BuildAll.xml retrieveAll && \
ant -f $WORKSPACE/_Build/_BuildAll.xml $ANT_ARGUMENTS -Daga.component=ui -Drun.tests=false -Dgenerate.javadoc=false -Drun.findbugs=false -Drun.checkstyle=false -Drun.pmd=false && \
ant -f $WORKSPACE/_Build/_BuildAll.xml gather
FROM ${AGA_REPO}base_aga${AGA_VERSION}
Once the 'orphan' problem happens, the docker container hangs between the two tasks.
The dockerd logs contain an interesting line which is the last one in the following snippet.
[jenkins#aga-slave-jenkins-lnx1 ~]$ journalctl -u docker.service |grep 'Jan 13' |tail
Jan 13 23:03:30 aga-slave-jenkins-lnx1.aga.net dockerd[11352]: time="2018-01-13T23:03:27-05:00" level=info msg="loading plugin "io.containerd.grpc.v1.namespaces"..." module=containerd type=io.containerd.grpc.v1
Jan 13 23:03:30 aga-slave-jenkins-lnx1.aga.net dockerd[11352]: time="2018-01-13T23:03:27-05:00" level=info msg="loading plugin "io.containerd.grpc.v1.snapshots"..." module=containerd type=io.containerd.grpc.v1
Jan 13 23:03:30 aga-slave-jenkins-lnx1.aga.net dockerd[11352]: time="2018-01-13T23:03:27-05:00" level=info msg="loading plugin "io.containerd.monitor.v1.cgroups"..." module=containerd type=io.containerd.monitor.v1
Jan 13 23:03:30 aga-slave-jenkins-lnx1.aga.net dockerd[11352]: time="2018-01-13T23:03:27-05:00" level=info msg="loading plugin "io.containerd.runtime.v1.linux"..." module=containerd type=io.containerd.runtime.v1
Jan 13 23:03:30 aga-slave-jenkins-lnx1.aga.net dockerd[11352]: time="2018-01-13T23:03:27-05:00" level=info msg="loading plugin "io.containerd.grpc.v1.tasks"..." module=containerd type=io.containerd.grpc.v1
Jan 13 23:03:30 aga-slave-jenkins-lnx1.aga.net dockerd[11352]: time="2018-01-13T23:03:27-05:00" level=info msg="loading plugin "io.containerd.grpc.v1.version"..." module=containerd type=io.containerd.grpc.v1
Jan 13 23:03:31 aga-slave-jenkins-lnx1.aga.net dockerd[11352]: time="2018-01-13T23:03:27-05:00" level=info msg="loading plugin "io.containerd.grpc.v1.introspection"..." module=containerd type=io.containerd.grpc.v1
Jan 13 23:03:31 aga-slave-jenkins-lnx1.aga.net dockerd[11352]: time="2018-01-13T23:03:27-05:00" level=info msg=serving... address="/var/run/docker/containerd/docker-containerd-debug.sock" module="containerd/debug"
Jan 13 23:03:31 aga-slave-jenkins-lnx1.aga.net dockerd[11352]: time="2018-01-13T23:03:27-05:00" level=info msg=serving... address="/var/run/docker/containerd/docker-containerd.sock" module="containerd/grpc"
Jan 13 23:03:31 aga-slave-jenkins-lnx1.aga.net dockerd[11352]: time="2018-01-13T23:03:27-05:00" level=info msg="containerd successfully booted in 0.274601s" module=containerd
I am a beginner in docker and wondering the issue might have to do with the booted containerd.
Thanks for your help!

Answer 1

Thanks for looking.
I came to believe too tight memory for the VM was causing or at least giving too much stress to my docker container.
It's running fine free of trouble with a doubled memory.
Not sure what exactly was going wrong with the small memory.