- EVENTS
- ATTRIBUTES
- METHODS
- Minion Notifications For Long Running Tasks 1 360
- Minion Notifications For Long Running Tasks 1 3rd
- Minion Notifications For Long Running Tasks 1 32
Minion::Notifier - Notify listeners when a Minion task has completed
Although Minion is a highly capable job queue, it does not natively have a mechanism to notify listeners when a job has finished or failed. Minion::Notifier provides this feature using pluggable Transport backends. Currently supported are Postgres, Redis, and WebSocket. Postgres support requires Mojo::Pg and Redis requires Mojo::Redis2. WebSockets are native to Mojolicious but you need a broker to manage the connections; Mercury is the author's suggested WebSocket message broker.
Note that this is an early release and the mechansim for loading plugins, especially third-party plugins is likely to change. Also note that due to the use of messaging buses, the order of events is not guaranteed especially on very fast jobs.
Minion – Notifications For Long Running Tasks 1.3 Description Black Friday discount! $23.99 to only $2.99! Today only Minion is the easiest way to monitor long running tasks on your Mac. Just tell it what to look for and Minion. Limit the maximum amount of processes or threads created by salt-minion. This is useful to avoid resource exhaustion in case the minion receives more publications than it is able to handle, as it limits the number of spawned processes or threads.1 is the default and disables the limit. Find Minion select it and press Modify You should have 2 entries to allow outbound 1 for TCP and UDP and one for just TCP. If not please post a screen shot. Also under the 'Tasks' tab at the top. Click on 'Check Security History'. Do you see anything related to Minion or mmoui.com? Maybe try Launching Minion first, then visit that location.
Minion::Notifier inherits all events from Mojo::EventEmitter and emits the following new ones.
enqueue
Emitted whenever any job is enqueued (typically having a state of 'inactive'). Note that the event is not repeated as an argument, though this is subject to change.
dequeue
Emitted whenever any job is dequeued for processing (typically having a state of 'active'). Note that the event is not repeated as an argument, though this is subject to change.
job
Emitted on any event from the backend for all jobs. The events are currently 'enqueue', 'dequeue', 'finished', and 'failed'.
job:$id
Emitted on any message from the backend for specific jobs. Note that the id is still passed so that you may reuse callbacks if desired. The events are currently 'enqueue', 'dequeue', 'finished', and 'failed'.
Users of this event are encouraged to carefully consider what race conditions may exist in the act of subscribing to it. For example,
Minion::enqueue
will emit the 'enqueue' event before it even returns the job's id. For this reason, this event is discouraged and may be deprecated/removed in a future release.finished
Emitted whenever any job reaches a state of 'finished'. Note that the event is not repeated as an argument, though this is subject to change.
failed
Emitted whenever any job reaches a state of 'failed'. Note that the event is not repeated as an argument, though this is subject to change.
Minion::Notifier inherits all of the attributes from Mojo::EventEmitter and implements the following new ones.
minion
The Minion instance to listen to. Note that this attribute is used to gain access to the 'application instance'.
transport
An instance of Minion::Notifier::Transport or more likely a subclass thereof. This is used to moderate the communication between processes and even hosts.
Minion::Notifier inherits all of the methods from Mojo::EventEmitter and implements the following new ones.
app
A shortcut for
$notifier->minion->app
.emit_event
A low level method used to emit the batch of events related to received minion events.
setup_listener
Setup the linkages that allow for notifications to be received. This is called automatically by Mojolicious::Plugin::Minion::Notifier once the ioloop has started.
setup_worker
Setup the linkages that cause the jobs to send notifications when reaching 'finished' or 'failed' states. This is called automatically by Mojolicious::Plugin::Minion::Notifier.
- Document all included classes (hey this is a preview release!)
- Improve backend loader mechanism
- Investigate timeout behavior for the various transport backends
- Mojolicious - Real-time web framework
- Minion - The Mojolicious job queue
- Mercury - A lightweight message broker using Mojolicious' WebSockets for transport
Joel Berger, <[email protected]>
Copyright (C) 2015 by Joel Berger
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
To install Minion::Notifier, copy and paste the appropriate command in to your terminal.
For more information on module installation, please visit the detailed CPAN module installation guide.
-->By Jeow Li Huan
In ASP.NET Core, background tasks can be implemented as hosted services. A hosted service is a class with background task logic that implements the IHostedService interface. This topic provides three hosted service examples:
- Background task that runs on a timer.
- Hosted service that activates a scoped service. The scoped service can use dependency injection (DI).
- Queued background tasks that run sequentially.
View or download sample code (how to download)
Worker Service template
The ASP.NET Core Worker Service template provides a starting point for writing long running service apps. Inpixio photo clip pro 1 1 900. An app created from the Worker Service template specifies the Worker SDK in its project file:
To use the template as a basis for a hosted services app:
Minion Notifications For Long Running Tasks 1 360
- Create a new project.
- Select Worker Service. Select Next.
- Provide a project name in the Project name field or accept the default project name. Select Create.
- In the Create a new Worker service dialog, select Create.
- Create a new project.
- Select App under .NET Core in the sidebar.
- Select Worker under ASP.NET Core. Select Next.
- Select .NET Core 3.0 or later for the Target Framework. Select Next.
- Provide a name in the Project Name field. Select Create.
Use the Worker Service (
worker
) template with the dotnet new command from a command shell. In the following example, a Worker Service app is created named ContosoWorker
. A folder for the ContosoWorker
app is created automatically when the command is executed.Package
An app based on the Worker Service template uses the
Microsoft.NET.Sdk.Worker
SDK and has an explicit package reference to the Microsoft.Extensions.Hosting package. For example, see the sample app's project file (BackgroundTasksSample.csproj).For web apps that use the
Microsoft.NET.Sdk.Web
SDK, the Microsoft.Extensions.Hosting package is referenced implicitly from the shared framework. An explicit package reference in the app's project file isn't required.IHostedService interface
The IHostedService interface defines two methods for objects that are managed by the host:
- StartAsync(CancellationToken):
StartAsync
contains the logic to start the background task.StartAsync
is called before:- The app's request processing pipeline is configured (
Startup.Configure
). - The server is started and IApplicationLifetime.ApplicationStarted is triggered.
The default behavior can be changed so that the hosted service'sStartAsync
runs after the app's pipeline has been configured andApplicationStarted
is called. To change the default behavior, add the hosted service (VideosWatcher
in the following example) after callingConfigureWebHostDefaults
: - The app's request processing pipeline is configured (
- StopAsync(CancellationToken): Triggered when the host is performing a graceful shutdown.
StopAsync
contains the logic to end the background task. Implement IDisposable and finalizers (destructors) to dispose of any unmanaged resources.The cancellation token has a default five second timeout to indicate that the shutdown process should no longer be graceful. When cancellation is requested on the token:- Any remaining background operations that the app is performing should be aborted.
- Any methods called in
StopAsync
should return promptly.
However, tasks aren't abandoned after cancellation is requested—the caller awaits all tasks to complete.If the app shuts down unexpectedly (for example, the app's process fails),StopAsync
might not be called. Therefore, any methods called or operations conducted inStopAsync
might not occur.To extend the default five second shutdown timeout, set:- ShutdownTimeout when using Generic Host. For more information, see .NET Generic Host in ASP.NET Core.
- Shutdown timeout host configuration setting when using Web Host. For more information, see ASP.NET Core Web Host.
The hosted service is activated once at app startup and gracefully shut down at app shutdown. Adguard 2 2 0 (643). If an error is thrown during background task execution,
Dispose
should be called even if StopAsync
isn't called.BackgroundService base class
BackgroundService is a base class for implementing a long running IHostedService.
ExecuteAsync(CancellationToken) is called to run the background service. The implementation returns a Task that represents the entire lifetime of the background service. No further services are started until ExecuteAsync becomes asynchronous, such as by calling
await
. Avoid performing long, blocking initialization work in ExecuteAsync
. The host blocks in StopAsync(CancellationToken) waiting for ExecuteAsync
to complete.The cancellation token is triggered when IHostedService.StopAsync is called. Your implementation of
ExecuteAsync
should finish promptly when the cancellation token is fired in order to gracefully shut down the service. Otherwise, the service ungracefully shuts down at the shutdown timeout. For more information, see the IHostedService interface section.Timed background tasks
A timed background task makes use of the System.Threading.Timer class. The timer triggers the task's
DoWork
method. The timer is disabled on StopAsync
and disposed when the service container is disposed on Dispose
:The Timer doesn't wait for previous executions of
DoWork
to finish, so the approach shown might not be suitable for every scenario. Interlocked.Increment is used to increment the execution counter as an atomic operation, which ensures that multiple threads don't update executionCount
concurrently.The service is registered in
IHostBuilder.ConfigureServices
(Program.cs) with the AddHostedService
extension method:Consuming a scoped service in a background task
To use scoped services within a BackgroundService, create a scope. No scope is created for a hosted service by default.
The scoped background task service contains the background task's logic. In the following example:
- The service is asynchronous. The
DoWork
method returns aTask
. For demonstration purposes, a delay of ten seconds is awaited in theDoWork
method. - An ILogger is injected into the service.
The hosted service creates a scope to resolve the scoped background task service to call its
DoWork
method. DoWork
returns a Task
, which is awaited in ExecuteAsync
:![Minion notifications for long running tasks 1 3rd Minion notifications for long running tasks 1 3rd](https://is5-ssl.mzstatic.com/image/thumb/Purple1/v4/a9/2e/ea/a92eead1-a5f0-745d-7579-833ccce2d361/pr_source.jpg/643x0w.jpg)
The services are registered in
IHostBuilder.ConfigureServices
(Program.cs). The hosted service is registered with the AddHostedService
extension method:Queued background tasks
A background task queue is based on the .NET 4.x QueueBackgroundWorkItem:
In the following
QueueHostedService
example:Minion Notifications For Long Running Tasks 1 3rd
- The
BackgroundProcessing
method returns aTask
, which is awaited inExecuteAsync
. - Background tasks in the queue are dequeued and executed in
BackgroundProcessing
. - Work items are awaited before the service stops in
StopAsync
.
A
MonitorLoop
service handles enqueuing tasks for the hosted service whenever the w
key is selected on an input device:- The
IBackgroundTaskQueue
is injected into theMonitorLoop
service. IBackgroundTaskQueue.QueueBackgroundWorkItem
is called to enqueue a work item.- The work item simulates a long-running background task:
- Three 5-second delays are executed (
Task.Delay
). - A
try-catch
statement traps OperationCanceledException if the task is cancelled.
- Three 5-second delays are executed (
The services are registered in
IHostBuilder.ConfigureServices
(Program.cs). The hosted service is registered with the AddHostedService
extension method:MonitorLoop
is started in Program.Main
:In ASP.NET Core, background tasks can be implemented as hosted services. A hosted service is a class with background task logic that implements the IHostedService interface. This topic provides three hosted service examples:
- Background task that runs on a timer.
- Hosted service that activates a scoped service. The scoped service can use dependency injection (DI)
- Queued background tasks that run sequentially.
View or download sample code (how to download)
Package
Reference the Microsoft.AspNetCore.App metapackage or add a package reference to the Microsoft.Extensions.Hosting package.
IHostedService interface
Hosted services implement the IHostedService interface. The interface defines two methods for objects that are managed by the host:
- StartAsync(CancellationToken):
StartAsync
contains the logic to start the background task. When using the Web Host,StartAsync
is called after the server has started and IApplicationLifetime.ApplicationStarted is triggered. When using the Generic Host,StartAsync
is called beforeApplicationStarted
is triggered. - StopAsync(CancellationToken): Triggered when the host is performing a graceful shutdown.
StopAsync
contains the logic to end the background task. Implement IDisposable and finalizers (destructors) to dispose of any unmanaged resources.The cancellation token has a default five second timeout to indicate that the shutdown process should no longer be graceful. When cancellation is requested on the token:- Any remaining background operations that the app is performing should be aborted.
- Any methods called in
StopAsync
should return promptly.
However, tasks aren't abandoned after cancellation is requested—the caller awaits all tasks to complete.If the app shuts down unexpectedly (for example, the app's process fails),StopAsync
might not be called. Therefore, any methods called or operations conducted inStopAsync
might not occur.To extend the default five second shutdown timeout, set:- ShutdownTimeout when using Generic Host. For more information, see .NET Generic Host in ASP.NET Core.
- Shutdown timeout host configuration setting when using Web Host. For more information, see ASP.NET Core Web Host.
The hosted service is activated once at app startup and gracefully shut down at app shutdown. If an error is thrown during background task execution,
Dispose
should be called even if StopAsync
isn't called.Timed background tasks
A timed background task makes use of the System.Threading.Timer class. The timer triggers the task's
DoWork
method. The timer is disabled on StopAsync
and disposed when the service container is disposed on Dispose
:The Timer doesn't wait for previous executions of
DoWork
to finish, so the approach shown might not be suitable for every scenario.The service is registered in
Startup.ConfigureServices
with the AddHostedService
extension method: Movavi screen recorder 11 activation key.Consuming a scoped service in a background task
To use scoped services within an
IHostedService
, create a scope. No scope is created for a hosted service by default.The scoped background task service contains the background task's logic. In the following example, an ILogger is injected into the service:
The hosted service creates a scope to resolve the scoped background task service to call its
DoWork
method:The services are registered in
Startup.ConfigureServices
. The IHostedService
implementation is registered with the AddHostedService
extension method:Queued background tasks
Minion Notifications For Long Running Tasks 1 32
A background task queue is based on the .NET Framework 4.x QueueBackgroundWorkItem (tentatively scheduled to be built-in for ASP.NET Core):
In
QueueHostedService
, background tasks in the queue are dequeued and executed as a BackgroundService, which is a base class for implementing a long running IHostedService
:The services are registered in
Startup.ConfigureServices
. The IHostedService
implementation is registered with the AddHostedService
extension method:In the Index page model class:
- The
IBackgroundTaskQueue
is injected into the constructor and assigned toQueue
. - An IServiceScopeFactory is injected and assigned to
_serviceScopeFactory
. The factory is used to create instances of IServiceScope, which is used to create services within a scope. A scope is created in order to use the app'sAppDbContext
(a scoped service) to write database records in theIBackgroundTaskQueue
(a singleton service).
When the Add Task button is selected on the Index page, the
OnPostAddTask
method is executed. QueueBackgroundWorkItem
is called to enqueue a work item: