Is there a way to start multiple virtual machines (instances) simultaneously in CloudStack?
Apparently this can't be done using the http user interface. Also, the http API request specifies only one id for targeting the virtual machine.
All I can think to solve this problem is to fire multiple individual start requests for each instance, then polling each of the job for results. Is there a better way?
CloudStack is an API driven system, if there is no API call where you can specify multiple VMs to be created (and I don't think there is), then it is not possible.
If you do need to create multiple machines (nearly) simultaneously, the only option I see is to fire multiple API calls, as you already mentioned.
See this answer on another question for a list of tools that make interfacing with CloudStack easier.
To start VM on cloudstack simultaneously tho in serial, I used cloudmonkey and created a bash script to setup a group of know VM UUID. See here for my experience
https://sites.google.com/site/cloudfyp/tutorial/cloudmonkey/commands-on-cloudmonkey
Related
Long story short - I need to use networking between projects to have separate billing for them.
I'd like to reach all the VMs in different projects from a single point that I will use for provisioning systems (let's call it coordinator node).
It looks like VPC network peering is a perfect solution to this. But unfortunately one of the existing networks is "legacy". Here's what google docs state about legacy networks.
About legacy networks
Note: Legacy networks are not recommended. Many newer GCP features are not supported in legacy networks.
OK, naturally the question arises: how do you migrate out of legacy network? Documentation does not address this topic. Is it not possible?
I have a bunch of VMs, and I'd be able to shutdown them one by one:
shutdown
change something
restart
unfortunately it does not seem possible to change network even when VM is down?
EDIT:
it has been suggested to recreate VMs keeping the same disks. I would still need a way to bridge legacy network with new VPC network to make migration fluent. Any thoughts on how to do that using GCE toolset?
One possible solution - for each VM in the legacy network:
Get VM parameters (API get method)
Delete VM without deleting PD (persistent disk)
Create VM in the new VPC network using parameters from step 1 (and existing persistent disk)
This way stop-change-start is not so different from delete-recreate-with-changes. It's possible to write a script to fully automate this (migration of a whole network). I wouldn't be surprised if someone already did that.
UDPATE
https://github.com/googleinterns/vm-network-migration tool automates the above process, plus it supports migration of a whole Instance Group or Load Balancer, etc. Check it out.
I'd like replace RExcel with the Excelsi-R. Excelsi-R talks R via RServe, and RServe has this feature, that makes each client work in independent workspaces.
What I want is to actually share a single workspace between at least 2 simultaneously connected clients. One client would be run by Excelsi-R, and another by manually launched interactive R Session. That would allow me to interface with the Excelsi-R session in traditional way (say, in RStudio).
I don't need asynchronous computation; I'm perfectly happy if Excelsi-R would have to wait, until a command issued by the other connection finishes, and vice versa; just like in the RExcel "foreground mode".
Is it possible?
Not currently, since each process has exactly one connection. There are a few hacks - such as you can "switch" sessions by starting a listener for another connection in an existing session - but that may be a bit too limited.
That said, it is technically possible (Rserve support looping over multiple connections - it is used in RCloud to support two separate processes on one connection) - the challenge is how to link two independent connections to a single process. The rsio communication was added in Rserve 1.8 specifically to allow the passing of descriptors between Rserve instances, but it was not used so far. If there is interest in that kind of functionality, I can see how it could be added.
How to make two VMs communicate with each other? I have to split a task between two VMs, so I think MPI has to be used, If so are there any useful resources that I can use to get started? Any help would be appreciated.
P.S : I have instaled devstack juno
Your question is not really clear.
Openstack is just a virtualization technology. There's almost no difference between having two hardware servers and two VMs. E.g. normally if two servers belong to the same network segment they will have access to each other's open ports. Openstack works just in the same way - if you assign the same network to VMs then this will also work.
However if you wish to install two VMs that will consume from a list of tasks and do them in parallel I would recommend you to read about Enterprise Integration Patterns (e.g. here). Technically this is implemented by using one or several messaging middleware servers such as ActiveMQ or ZeroMQ.
By reading documents on MSDN, I realized that it is recommended to create separate hosts by functionality (Sending hosts, Receiving hosts and Processing hosts). And if there is only one host in this bizTalk server, this host can perform all receiving, sending, and processing messages functionality.
My question is: Is it possible to have multiple hosts that each host can perform its own sending, receiving and processing function , and not affect each other?
This is for multiple developers working on the same project, because our current situation doesn't allow us to have a full set of SQL Server Database and SQL server for each developer or using VM.
Thanks a lot!
Multiple hosts is not a solution for letting multiple developers work on a single server. A single send/receive adapter can only be assigned to one host.
You will also run into other problems, as all the configuration settings are shared in a single database, a change from 1 developer will effect the others.
This same question was asked and answered at MSDN. What you are trying to do is not supported and will not work. There is no way around this.
You must deploy the same application code to each computer in a BizTalk Group.
Sharing a BizTalk computer for development work is not a workable or productive solution and will have a definite negative affect on productivity.
You are correct, the best way to handle DEV is a VM with the entire stack. This is the issue you must address in your environment.
Consider the following situation:
You have an application you are tesing, but in order to test the networking functionality of said program, you are required to run multiple instances of it and have them communicate with one another.
Possible solutions are:
- Run software on individual machines connected by WAN or LAN.
- Run the software on virtual machines, all on the same computer.
I do not want to use either of these methods (the reasoning is irrelevant). I want to know if there is a way that I can reroute network transmissions from the test application (ideally in any programmming language) in a way such that I can run multiple instances of the same software on one computer, and have them behave as if they were the only instance running on that computer.
In other words, I want to be able to code the application so that each instance listens on the same "listening" port (since only one instance will be running on each computer when in production). Then, I want to know if I can reroute the network requests at a lower level then the application so that they do not interfere with eachother (clash over the same port number).
Essentially, I want to build a virtual environment which only redirects the network calls (whereas a virtual machine takes far more resources, and has way more involved). Is this possible, and how might I approach this problem?
Thank you!
UPDATE: This is a more accurate idea of what I want to accomplish:
Basically, I want to program another application which TRANSPARENTLY redirects bind requests to available ports, and manages which applications are bound where... So from the applications perspective, all the instances are bound to port 1000, but in reality, this other application is automatically managing which instance is bound where, and avoiding potential conflicts. I feel like this could be accomplished with Windows Hooks, but I'm not sure how you could implement this?
As far as I know, there is no sane way to multiplex the same port on the same network device. At the very minimum, you will need to choose on of the following:
Run each instance of your program on a different port
Create multiple virtual network interfaces
The first choice is easy and may be the one I would choose. The second one is more towards what you are looking for but it would be a true PITA to set up - you can look into VirtualBox and its host-only networks for inspiration. If you are writing things on linux you might look into pipes and chrooting but you'll be spending more time setting up this environment than writing your software.