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Budget of $330,000

To Do

  • Done: Find a spot at DSOC for test system.  253T if we buy a rack.
  • Talk with SSA and VLASS about how we actually use these remote clusters (e.g.Staging, flocking, etc)
  • Get account number and routing number.
  • Buy test system
  • Talk with Pueto Rico about their technical situation
  • Ask David if there are enough Red Hat licenses for RADIAL or if we will need to get more licenses
  • Think about getting drives from third party instead of Dell and sparing them ourselves.
  • prefer 208V for us and the remote site(s)
    • Install a 208V circuit for our reserved space (253T) in the server room.
    • Could use PD1-B breakers 7, 9, 11
  • Think about getting the same drives for the OS that we get for the data array.  It's simpler but perhaps slower.
  • Who is going to put all the RAM and drives in the servers?
  • Work on a price spreadsheet

Timeline

  • Buy test system as soon as practical (assuming the project is still a go)
    • Does Jeff Kern know if this is a go or not
      • Tony apparently told Jeff it is still a go.
    • Done: Talk to Matthew about where to put this stuff
      • May 3, 2022 krowe: talked to Matthew and Peter.  RADIAL has space 253T reserved.
  • Buy production system by July
  • Receive production system by Aug
  • Install production system by Dec
  • Running in Jan. 2023


Data Path

This is conceptual at this point.  Need to talk with SSA and VLASS about this.

  • We pre-stage data on the remote head node
  • We then either submit a job locally and it flocks to the remote site or we login to the remote site and submit from there.
    • Can we use a nifty filesystem to simplify this (Ceph or that LHC fs)?
    • This might be a good phase2 problem to solve.
    • Is this kinda what nraorsync does?
  • The remote execute hosts transfer data from the remote head node
  • The job uploads resulting data to the remote head node
  • We retrieve data from the remote head node


Using

  • Get NRAO jobs on the remote racks.  This may depend on how we want to use these remote racks. If we want them to do specific types of jobs then ClassAd options may be the solution. If we want them as overflow for jobs run at NRAO then flocking may be the solution. Perhaps we want both flocking and ClassAd options.  Actually flocking may be the best method because I think it doesn't require the execute nodes to have external network access.
    • Staging and submitting remotely?
    • Flocking?
    • Classad options?  I think this will require the execute hosts to have routable IPs because our submit host will talk directly to them and vice-versa.  Could CCB help here?
    • Other?
  • Remote HTCondor concerns
    • Do we want our jobs to run an NRAO user like vlapipe, or nobody?
    • Do we want remote institution jobs to run as the remote institution user, some dedicated user, or nobody?
  • Need to support 50% workload for NRAO and 50% workload for remote institution.  How?
  • Share disk space on head node 50% NRAO and 50% remote institution
    • Two partitions: one for NRAO and one for remote institution?


Documentation

  • A projectbook like we did for USNO could be appropriate
  • Process diagrams (how systems boot, how jobs get started from NRAO and run, how remote institutions start jobs, etc)


Networking

HTCondor flocking requires

  • From local schedd to remote collectord on condor port 9618
  • From remote negotiator and execute hosts to local schedd.  Here the execute hosts can be NATed.
  • From local shadow to remote starterd.  Use CCB.  It allows execute hosts to live behind firewall and be NATed.

Non-flocking just requires ssh access from probably mcilroy and to gibson

NRAO side

  • NRAO -> remote head node on port 22 (ssh)
  • Submit Host -> remote head node (condor_collector) on port 9618 (HTCondor) for flocking
  • Submit Host <- remote head node (condor_negotiator) on port 9618 (HTCondor) for flocking
    • mcilroy has external IPs (146.88.1.66 for 1Gb/s and 146.88.10.66 for 10Gb/s).  Is the container listening?
  • Submit Host <- remote execute hosts (condor_starter) on port 9618 (HTCondor) for flocking
  • Submit Host (condor_shadow) -> remote execute hosts (condor_starter) on port 9618 (HTCondor) for flocking.  CCB might alleviate this.

Remote side

  • Head node <- from nrao.edu on port 22 (ssh)
  • Head node -> revere.aoc.nrao.edu on port 25 (smtp)
  • Head node -> NRAO Submit Host on port 9618 (HTCondor) for flocking
  • Head node <- NRAO Submit Host on port 9618 (HTCondor) for flocking
  • Execute node -> NRAO Submit Host on port 9618 (HTCondor) for flocking.  Execute host may be NATed.
  • Execute node -> gibson.aoc.nrao.edu on port 22 (ssh) for flocking with nraorsync.  Execute host can be NATed.


Services

  • DNS
    • What DNS domain will these hosts be in?  nrao.edu? remote-institution.site? other?
  • DHCP
  • SMTP
  • NTP
  • NFS
  • LDAP?  How do we handle accounts?  I think we will want accounts on at least the head node.  The execution nodes could run everything as nobody or as real users.  If we want real users on the execute hosts then we should use a directory service which should probably be LDAP.  No sense in teaching folks how to use NIS anymore.
    • remote institution accounts only?
  • ssh
  • rsync (nraorsync_plugin.py)
  • NAT so the nodes can download/upload data
  • TFTP (for OSes and switch)
  • condor (port 9618) https://htcondor-wiki.cs.wisc.edu/index.cgi/wiki?p=HowToMixFirewallsAndHtCondor
  • ganglia
  • nagios


Operating System

  • Must support CASA
  • Will need a patching/updating mechanism
  • How to boot diskless OS images
  • What Linux distrobution to use?
    • Can we use Red Hat with our current license?  I have looked in JDE and I can't find a recent subscription.  Need to ask David.
      • We have a 1,000 FTE license with up to 20,000 installations allowed.  But since we are either selling the equipment to the institution or asking them to buy it themselves, at least with UPRM, I don't see how we can use our RHEL license legally.  Asking each institution to aquire an RHEL license sounds like a recepie for failure so I think open source OS is the answer.
    • Should we buy Red Hat licenses like we did for USNO?
      • USNO is between $10K and $15K per year for 81 licensed nodes.  This may not be an EDU license.
      • NRAO used to have a 1,000 host license for Red Hat but I don't know what they have now.
      • I don't want to maintain licenses for up to 10 differenct installs.  I don't think the institutions will want to purchase and maintain a license.
    • Do we even want to use Red Hat?
      • Alternatives would be Rocky Linux or AlmaLinux or CentoOS Stream
  • What version do we use RHEL7 or RHEL8 or RHEL9?
  • What OSes is CASA is verified against?  I am pretty sure RHEL but what about CentOS or Rocky or ALMA, etc?.
  • The cost of RHEL is pretty small compared to the hardware.
  • UPRM has their own money but the other institutions will either get a grant or money from us so we can say what OS they use and pay for.
  • Should pull in Matthew or Schlake on this decision.
  • Should we use Ansible for deployments?

Third party software for VLASS

  • CASA
  • HTCondor
  • Will need a way to maintain the software
    • stow, rpm, modules, containers?

Third party software for remote institution

  • Will need a way to maintain software for the remote institution site
  • Will need a way to maintain the software
    • stow, rpm, modules, containers?


Management Access

  • PDU
  • UPS
  • BMC/IPMI
  • switch

Maintenance

  • replace disk (remote institution admin)
  • replace/reseat DIMM (remote institution admin)
  • replace power supply (remote institution admin)
  • NRAO may handle replacement hardware. Drop ship. Spare ourselves?
  • Patching OS images (NRAO)
  • Patching third party software like CASA and HTCondor (NRAO)
  • Altering OS images (NRAO)

Hardware


Shipping

  • Drop ship everything to the site and assemble on site.  This will require an NRAO person on site to assemble with a pre-built OS disk for the head node.  I think this is too much work to do on site.
    • Install DIMMs in nodes
    • Install NVMe drives in nodes
    • Rack everything
    • Cable everything
    • Configure switch
    • Install/Configure OS
  • Ship everything here and assemble then ship a rack-on-pallet.
  • Mix the two. Ship minimal stuff here (head node, switch, couple of compute nodes, etc) and configure and drop ship most of the nodes to the site.
    • Re-ship head node, switch, compute nodes to site
    • Re-ship memory and drives to site
  • A person from the remote site could travel to NM or CV to see the test system and get instruction.


Other

  • Keep each pod as similar to the other pods as possible.
  • Test system at NRAO should be one of everything.
  • Since we are making our own little OSG, should we try to leverage OSG for this or not?  Or do we want to make each POD a pool and flock?
  • Should we try to buy as much as we can from one vendor like Dell to simplify things?
  • APC sells a packaged rack on a pallet ready for shipping.  We could fill this with gear and ship it.  Not sure if that is a good idea or not.  We will not be able to move the unit into the server room while still on the pallet because no doorway is tall enough.  We would have to roll it off the pallet (it comes with a ramp and the rack is on casters) move it into the server room, fill and configure it, roll it out of the server room, roll it back onto the pallet, probably remove the bottom server(s) so we can attach it to the pallet, then re-add the bottom server(s).  We could use the double glass doors for this but there is a lip on the transition.  We could use the doors in the PRA closet as it has no lip but would require a lot of moving of shelves and stuff.
  • APC NetShelter SX packaged:
    • On Pallet: Height 85.79in (2179mm) Width 43.5in (1105mm)
    • On Casters: Height 78.39in 1991mm) Width 23.62in (600mm)
  • NRAO Dimensions
    • Double Glass doors: Height: 80in (2032mm) (because of the 2in maglock)
    • NRAO-NM wide server doors: Height: 83in (2133mm) Width: 48in (1187mm)
  • I could start prototyping now using AWS.
  • If jobs are submitted from the remote head node, does that mean SSA will want a container on that remote head node?



Site Questions

  • Voltage in server room (120V or 208V or 240V)
  • Receptacles in server room (L5-30R or L21-30R or ...)
  • Single or dual power feeds?
  • Is power from below or from above?
  • How stable is their power?
  • Is there a UPS?
  • Is there a generator?
  • Door width and height and path to server room.
    • Can a rack-on-pallet fit upright?  Height: 85.79inches (2179mm) Width: 43.5inches (1105mm)
    • Can a rack-on-casters fit upright?  Height: 78.39inches (1991mm) Width: 23.62inches (600mm)
    • NRAO-NM wide server door Height: 84inches (2108mm) Width: 46.75inches (1219mm)
  • Firewalls
  • How are you going to use this?
  • Do you care if this is in your DNS zone or ours?
  • Is NAT available for the execute hosts?


Resources

  • USNO correlator (Mark Wainright)
  • VLBA Control Computers (William Colburn)
  • Red Hat maintenance (William Colburn)
  • Virtual kickstart (William Colburn)
  • Switch models and ethernet (Jeff Long)
  • HTCondor best practices (Greg Thain)
  • OSG (Lauren Michael)
  • SDSC at UCSD
  • TACC at UT Austin
  • IDIA https://www.idia.ac.za/



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