So far, based on my understanding of OpenStack Python SDK, I am able to read the Hypervisor, Servers instances, however, I do not see an API to receive and handle the change notification/events for the operations that happens on the cluster e.g. A new VM is added, an existing VM is deleted etc.
There is a similar old post (circa 2016) and I am curious if there have been any changes in Notification handling?
Notifications to external systems from openstack
I see a documentation, which talks about emitting notifications over a message bus that indicate different events that occur within the service.
https://docs.openstack.org/ironic/latest/admin/notifications.html
I have the following questions:
Does Openstack Python SDK support notification APIs?
How do I receive/monitor notifications for VM related changes?
How do I receive/monitor notifications for compute/hypervisor related changes?
How do I receive/monitor notifications for Virtual Switch related changes?
I see other posts such as Notifications in openstack and they recommend to use Ceilometer project, which uses a Database. Is there more light-weight solution than using a completely different service like Ceilometer?
Thanks in advance for your help in this regard.
As far as I see and I know, Openstack SDK doesn't provide such a function.
Ceilometer will also not help you. It only collects data by polling and by notifications over RPC. You would still have to poll the data from ceilometer by yourself. Beside this, ceilometer alone has the problem, that it only grow and will blow up your database, that's why you should also use gnocchi, when you use ceilometer.
At the moment I see only the 3 possible solutions for you:
Write your own tool, which runs permanently in the background and collect the data in a regular interval over OpenstackSDK and REST-API requests.
Write something, which does the same like ceilometer by reciving notifications over oslo-messaging (RPC). See the oslo_messaging_notifications-section in the configs: https://docs.openstack.org/ocata/config-reference/compute/config-options.html#id35 (neutron has also such an option) and use messagingv2 as driver like ceilometer does. But be aware here, that not every event creates a notification. The list of the ceilometer meter-data should give a good overview of which event are creating a notification and what can only be collected by polling: https://docs.openstack.org/ceilometer/pike/admin/telemetry-measurements.html. The number of notification-events is really low, so its possible, that it doesn't provides all events you want.
Use in the oslo_messaging_notifications-section in the configs log as driver to write the notification in a log-file, and write a simple program to read the log-file and process or forward the read content. Here is the same problem like in number 2, that not every event creates a notification (log-entry in this case here). This has also the problem, that the notifications and so also the event-logs, are created on the compute-nodes (as far as I know) and so you would have to watch all compute-nodes by your tool.
Based on the fact, that I don't know, how much work it would be to write a tool to collect notifications over RPC and because I don't know, if all events you want to watch really creates a notification (base on the overview here: https://docs.openstack.org/ceilometer/pike/admin/telemetry-measurements.html), I would prefer number 1.
Its the easiest way to create a tool, which runs GET-Requests over REST-API in a regular interval and forward the results to the desired destination as your own custom notifications.
I followed the below references to get this working. Also, chatted with the author of this code and video.
https://github.com/gibizer/nova-notification-demo/blob/master/ws_forwarder.py
https://www.youtube.com/watch?v=WFq5JWXa9AM
In addition, I faced other issues:
By default, OpenStack server would not allow you to connect to RabbitMQ bus from remote host because of an IPTABLE rule. You will have to enable access to the RabbitMQ Port in the IP table.
Related
I need to create a web UI for a client company to allow them to monitor which subscribers (Microservices) are up and if they are part of a worker queue, how many of them are running.
Although this is easy to implement by keeping sending a signal to another instance of NATS (to minimize overheads) for monitoring, I would like to ask if there is any built-in feature that can provide this functionality.
This link suggests that there is a monitoring endpoint built-in but I am not sure if I can get what I need out of it. So do I have to start inventing the wheel, or is there something that can be used out of the box?
I'm developing an on-site WinRT application and would like to send push notifications when a new update is available (since it's an on-site app, the installation process requires a custom loader rather than the Windows Store app).
However, I'm trying to wrap my head around how such a system should ideally function.
I could obviously create a service which returns the latest version number and the app would periodically poll the service for that info. It would be easy to implement, but it seems like a very ugly approach (the need to send constant requests for the latest version doesn't seem like an elegant one).
I have the power of Azure at my disposal. Obviously a Notification Hub would be the preferred way. HOWEVER, I have no intention of getting a Windows Store account purely to develop a "private" on-site application. So using the Notification Hub is a no-go.
I've thought about using topics. This WOULD work, but every client would probably need to be added as a subscriber. While technically possible, the administrative overhead could be a major issue. I also thought about creating the subscribers dynamically by the WinRT application itself. However the SDK (Azure Messaging Managed) for handling this is too old and always throws an error (invalid date format, which apparently was changed at some point) when creating subscribers. The only "current" package from MS seems to be for the full .NET framework, not the limited WinRT counterpart.
I'm looking for ways around this problem. Either a newer, proper SDK (which can handle listing and creating subscriptions as well as receiving topic), or perhaps a completely different approach to the problem.
Note - I don't need any code just yet. Pseudocode or simply a description on how the communication would work should suffice.
For a limited scale deployment, Service Bus Topics may quite well be a feasible choice. Or you may want to take a look at IoT Hub as an alternative push notification channel.
The new Service Bus client SDK for .NET Standard lives this repo, but we do not build binaries as of yet: https://github.com/Azure/azure-service-bus-dotnet
I want to check anyone phonenumber's online status by query from serverside without any notice to user. Is it even possible?
An operator can see the latest location updates etc from a mobile device, but I am guessing this is not your use case.
To do it as a third party service, you would need to either implement an instant messaging like availability service or leverage or extend an existing open source one like Tox (https://tox.chat), Telegram (https://telegram.org), Linphone (http://www.linphone.org) etc.
All,
I have completed the basic GAE "Guestbook" example which uses Google Cloud Endpoints and Google Cloud Messaging. I can successfully add a note to the guestbook and have it appear on all registered devices.
I've also used the super simple Server Sent Event (SSE) mechanism to have a web page initiate an event source and then update itself as events are received. But separate web pages appear to create their own distinct event sources (even if using the same URI to the event source) and thus get their own events at their own times.
The objective here is to create a bit of collaboration such that user actions can come from an android device or a web page and the effects the received action are then pushed to all connected users/devices/web pages.
I have assumed I will need a background module and that both Endpoints and 'normal' web pages / queries would channel the received user action to that background module. I believe I can get that far. Next, I need the background module to trigger a push notification to all interested parties.
I believe I can trigger a Google Could Messaging event to registered Android devices from that background module.
But it isn't clear to me how a background module can be the source of an SSE, or how the background module can best communicate with a foreground module that already is the source of an SSE.
I've looked at the Google Queue API, but I have a feeling I'm making something quite easy much more difficult than it needs to be. If you were not going to 'poll' for changes from a web page... and you wanted to receive notifications from an SSE source when changes were made by other users, possibly using Android devices rather than a typical web page, and the deployed application is running on the Google Application Engine, what would you recommend?
Many thanks,
Randy
You are on the right track, not really sure why you are using the background module but from what i understood you need to:
Your front end module receives an update
You retrieve a list of all devices receiving that update
Use the Queue service to send the update via GCM to every single device
Why use queues? because front end instances have a 1 min time limit per request and you'll need to queue work in order to go beyond that time to serve you (potentially) thousands of users.
Now, If you already have a backend instance (which does not have the 1min limit) you could just iterate over the list and send all messages on one request. I believe you have a 24 hr request limit so you should be OK. But in this scenario you don't have need for the front end module, you can just hit this server straight up.
I'm evaluating Urban Airship as a push solution and I was wondering if it's possible to export my device tokens should I decide to stop using their service?
I've noticed they have an API endpoint to download device data (http://docs.urbanairship.com/reference/api/v3/device_information.html#device-token-list-api) but I was wondering if anyone actually went through the process of switching their push solution from UA to an internal solution (i.e. run my own push server and ping old users).
Thank you!
I'm not sure if there is an API call for it, but you could go to Audience->device tokens, and make a script to fetch all of them.
In the company I work, we decided on a different approach.
All communication with Urban Airships goes through our own backend, where we at the same time store the devicetokens sent from the device. That way we can shift to another way of sending push notifications without modifying our apps. It is of course a bit more time consuming to do the initial development. On the other hand, if you go for the solution you are currently considering, the switch to you own implementation (or another push provider) will properly require several migrations, or at least maintaining two different ways of sending push notification for a considerable time.
BTW:we have been using UA for almost 3 years, and have been very happy with their service.