Developer Guide: Maintaining an installation

Monitoring

Tail log output of all containers with docker-compose -p <Project Name> -f <Your docker-compose.yml> logs -f.

Use docker stats to show CPU, memory, network read/writes, and total disk read/writes for running containers.

Finding problems on running Manager

Use jstat to monitor a running system/JVM. The following command will connect to a Manager and print garbage collection statistics (polling 1000 times, waiting for 2.5 seconds):

docker exec -it <Manager Container ID/Name> /usr/bin/jstat -gcutil 1 2500 1000

The output contains:

S0: Survivor space 0 utilization as a percentage of the space's current capacity.
S1: Survivor space 1 utilization as a percentage of the space's current capacity.
E: Eden space utilization as a percentage of the space's current capacity.
O: Old space utilization as a percentage of the space's current capacity.
M: Metaspace utilization as a percentage of the space's current capacity.
CCS: Compressed class space utilization as a percentage.
YGC: Number of young generation GC events.
YGCT: Young generation garbage collection time.
FGC: Number of full GC events.
FGCT: Full garbage collection time.
GCT: Total garbage collection time.

Restarting a Manager with new settings

To get more details or set JVM options, edit your docker-compose.yml and change or add an entrypoint section:

  manager:
    entrypoint:
      - "java"
      - "-Xmx1024m"
      - "-XX:+PrintGCDetails"
      - "-cp"
      - "/opt/app/lib/*"
      - "org.openremote.manager.server.Main"

Then restart the service with:

SERVICE=manager && PROJECT=<Your project name> && PROFILE=<Your docker-compose.yml> && \
  docker-compose -p $PROJECT -f $PROFILE stop $SERVICE && \
  docker-compose -p $PROJECT -f $PROFILE rm -f $SERVICE && \
  docker-compose -p $PROJECT -f $PROFILE create $SERVICE && \
  docker-compose -p $PROJECT -f $PROFILE start $SERVICE