Words and their Meanings

We will try to avoid using ambiguous terms like 'NGAS server' in favor of more specific terms:

  • NGAS Service: an instance of the the NGAS software running on an NGAS node.
  • Service Number: an enumeration of the NGAS services running on an NGAS node 
  • Port Number: the tcp/ip port an NGAS service listens to.
  • NGAS Node: a computer running one or more NGAS services.
  • NGAS Cluster: one or more NGAS nodes sharing a common cluster name and relational database.
  • NGAS Root directory: the base directory a service executes from.
  • NGAS Volume: a storage partition NGAS uses to store files
  • NGAS Copy Node: an NGAS Node that is a duplicate of another NGAS node, using subscription or rsync

NGAS Node Host Names

Server host names follow this general format and should be under 128 characters long:

$SITE-$CLUSTER-ngas-$PROFILE-$NUMBER, e.g. soc-ssa-ngas-prod-001


What the Node Host Name Components Mean

$SITE

$CLUSTER

$PROFILE

$NUMBER

 2 to 3 lowercase letters representing site location:

  • cv: Charlottesville, Virginia
  • soc: Socorro, New Mexico
  • gb: Green Bank, West Virginia
  • uva: University of Virginia
  • nmt: New Mexico Tech

Non-NRAO Sites:

  • jao: Joint ALMA Observatory (Chile)
  • eso: European Southern Observatory (Germany)
  • naoj: National Astronomy Observatory (Japan)
  • naasc
  • ssa
  • gbo
  • prod: production
  • test: test
  • dev: development
  • copy: duplicate


001 onwards

Mapping Old Node Host Names to New Node Host Names

Old Name

New Name

Old NameNew Name
nmngas01soc-ssa-ngas-prod-001cvngas01cv-ssa-ngas-prod-001
nmngas02soc-ssa-ngas-prod-002cvngasttest01cv-ssa-ngas-test-001
nmngas03soc-ssa-ngas-prod-003cvngas01-mirroruva-ssa-ngas-copy-001
nmngas04soc-ssa-ngas-prod-004vegas-arc-03uva-ssa-ngas-prod-001
nmngas01mirrornmt-ssa-ngas-copy-001vegas-arc-04uva-ssa-ngas-prod-002
nmngas02mirrornmt-ssa-ngas-copy-002ngas-01cv-naasc-ngas-prod-001
nmngas03mirrornmt-ssa-ngas-copy-003ngas-02cv-naasc-ngas-prod-002
nmngas04mirrornmt-ssa-ngas-copy-004ngas-03cv-naasc-ngas-prod-003
nmngastest01soc-ssa-ngas-test-001

nmngastest02soc-ssa-ngas-test-002

Ports and Service Numbers

A given NGAS node can be configured to run more than one service, this can be described as a service number and a port number. The first service on a node will be service number 1, and it will bind to port 7777. Subsequent services increment both the service number and port number, so the second service on a node would be service number 2, port 7778, and so on.

Partition Names and Mount Points

  • NGAS nodes will have one root directory per service:
    • The root directory will be /NGAS$Number, so, /NGAS1 for the first service, /NGAS3 for the third and so on.
    • Nodes that will only run one service can use /NGAS for the root directory, omitting the service number.
  • Volumes will be named VolumeNN, where NN is a zero padded number starting at 1, so Volume01, Volume02 and so on.
  • Volumes will be mounted at $ROOT_DIRECTORY/volumes/$VOLUME_NAME
    • e.g. /NGAS2/volumes/Volume03, /NGAS/volumes/Volume12

Alerts, Monitoring & Logging

  • We will aggregate logs in the SSA metrics server.
  • We will provide service interruption alerts via Slack
  • We will track the load on the NGAS servers via the metrics server
  • This will be set up and configured on each host via an Ansible playbook
  • No labels