Oauth2/OIDC: I know the address of a resource server, is there a standard for querying which authorization servers it accepts?

I have a bunch of what are essentially IOT devices that will authenticate connections using oauth 2 tokens and/or openid connect (depending on use-case). Each IOT device is individually configurable with one or more authorization servers (ie. each has a client-id/client-secret with one or more auth servers).

My problem is that, given the URI/address of the IOT device, is there an RFC or standard for determining the address(es) of authorization servers that IOT device trusts?

I am going to build a console-like application that will need to be able to connect to many (thousands) of these devices. I control the code on the IOT device and can build something proprietary in, but I’m trying to follow relevant RFCs, where applicable. I have thus far found no specification for querying a resource server to determine the configured authorization servers.

how to automatically launch multiuser vnc servers on boot using vnc4server on ubuntu 16.04?

I’m trying to setup vnc4server on ubuntu 16.04 machine now. Previously someone installed TightVNC for a single user but I found some problem (vnc window sometimes stalls when I move some graphic window around) so I installed vnc4server. (in the past , I learned vnc4server doesn’t have that problem.). The vncserver alternatives is set to vnc4server(using update_alternatives --config vncserver).
ok, vnc4 server runs ok, but I don’t know how to let the vnc servers start automatically after the boot each for multiple users. In the past, I used to have /etc/vncserver/vncservers.conf and speicified all the vnc parameters there like (I’m not sure it was for vnc4server) :

VNCSERVERS="1:ckim 11:jchung" VNCSERVERARGS[1]="-geometry 2460x1500" VNCSERVERARGS[11]="-geometry 3840x2160"   

I think I have missed something important for letting the vnc service start automatically. What should I do? (of course each user can start vncserver with like vncserver :7).

How to test server’s peak draw on electrical amperage?

I’m moving my server to a co-location center and they’r not concerned with the actual wattage, which is what I’ve tracked, but they are very concerned with the peak amperage. They charge by the amps made available to the machine. Is there some industry standard way I can test that? The person I spoke with in the data center is a sales guys, so he’s not sure of the technical aspects that he’s asking me about.

If there’s a software solution, my system is an HP DL580 G7 running centos 7.

What I’ve tried:

I have a UPS on it now that gives wattage outputs which bounce all over the place. The highest I’ve seen is 800 watts, so my guess is 800watts/120volts should be six and two thirds amps. Do I provision 7 amps? Sounds a little flimsy.

Powerstat says “Device does not have any RAPL domains, cannot power measure power usage.” so I don’t think it’s compatible with my system.

Please let me know what the industry standards for this are.

Android TV showing “There was a problem communicating with Google servers, try again later” error

I just got a new Android TV box and am trying to sign into Google play store but every time I put in the information and hit enter the error “There was a problem communicating with Google servers, try again later” pops up. I have cleared the data on Google play store and Google play services and have restarted my TV but nothing works. What should I do? How do I solve this problem?

Failing over PULL servers

I have a server that’s pulling data from another server, formatting it and passing it on. I have a standby configured to take its place if it fails, but because two servers can’t pull simultaneously, the pull process is turned off in the secondary server. In the event of a primary server failure I will need to login and start up the process in the secondary server. Normal fail-over architecture doesn’t work, of course, because the source doesn’t send any information – it just passively responds to requests. I need a solution that will recognize that one server failed and automatically start a process on another server. Any ideas on how this could be automated?

Performance of TensorFlow in a virtual machine on old servers

I’d like to enlist some old servers (e.g, G5 HP servers) for TensorFlow distributed computation. They’re running Windows 2012 r2 on the bare-metal. I’m thinking about creating a Ubuntu virtual machine guest on the servers with VirtualBox or Hyper-V to operate as the TensorFlow cluster workers.


  1. Has anyone done any performance benchmarking on a similar set-up (a) between different virtualization software, and (b) versus bare-metal?

  2. Are there any customizations / configurations that should be used to maximize performance on this set-up?

I note that I was unable to install modern operating systems (e.g., Ubuntu 16 and 19 and CentOS7) on the bare-metal because of antiquated RAID controllers that can’t be disabled (hence why I’m exploring virtualization).

Should I use public IP or private IP for connecting servers within the same VPC?

I have 2 Linux servers on AWS. Both servers are in the default vpc (aws default vpc). Both of these servers have their own Elastic IP. I also have a webServer which is inside the same vpc.

I want to run a replicated MySQL on these 2 servers, so one server would be master and the other slave.

I need to provide an ip address for each MySQL server, so in my.cnf, there is a setting: bind-address

Should I use the public or private IP for the bind-address or the private IP? (All the computers who need access to MySQL server are in the same vpc).

Note both servers are in the same Security Group and I have opened all the ports within the security group.