I'm looking for an open source/free task scheduler for Windows 7 (development machine) that will allow me to schedule tasks (HTTP requests to a web service) to run every x seconds.
I've tried a couple of Cron clones and windows own Task Scheduler but neither seem to allow tasks to run at intervals less than 60 seconds. Am I missing something? I don't want to have to go and write any custom scripts either if possible.
It is possible to create multiple triggers for one scheduled task. If you create 59 identical triggers with an offset of 1 second to each other, and schedule the task itself to run every minute, you end up the scheduled task to run every second.
You could create those 59 triggers manually using the GUI. However, a much quicker way to create so many triggers is to create a task with one or two triggers, export it to a text file, duplicate the according lines, change the start offsets accordingly, and then re-import the file.
I was actually able to achieve this.
Update: Seems I over complicated it.
In the trigger, where it says "Repeat task every:" you can actually TYPE into the drop-down "1 minute" (It wont let you type the time in seconds)
I did this on a Windows 7 machine.
Also, I clearly did not read the question well enough, as the asker seems to already have been able to get the time down to 1 minute. However, I'll leave this answer here, as it will explain for future readers exactly how to get the time down to one minute.
It does seem as though you cannot get it to run at an interval of less than one minute.
I set up a task with a trigger set to Daily to recur every 1 day.
I check the "Repeat task every:" box. Setting it to 5 Minutes for a duration of 1 day
This makes the task go forever, every 5 minutes.
I then exported the task. It exports to a .xml file.
Under Task > Triggers > CalendarTrigger > Repeition there is the following tag: <Interval>PT5M</Interval> I changed it from PT5M to PT1M. I re-imported the task.
The task now runs every 1 minute.
I have not fully tested this, and I have not tried with less than one minute, but it might be possible by putting PT30S or something for 30 seconds. I'll try it out and report back. Update: You cannot do this, you get an error when importing the task. It's not possible to set this time to less than 1 minute.
The whole trigger looks like this for me:
<Triggers>
<CalendarTrigger>
<Repetition>
<Interval>PT1M</Interval>
<Duration>P1D</Duration>
<StopAtDurationEnd>false</StopAtDurationEnd>
</Repetition>
<StartBoundary>2013-11-07T17:04:51.6062297</StartBoundary>
<Enabled>true</Enabled>
<ScheduleByDay>
<DaysInterval>1</DaysInterval>
</ScheduleByDay>
</CalendarTrigger>
</Triggers>
I've googled this to death, so as far as I can see the answer is, there are none. There are plenty of commercial solutions, but no open source/free programs.
I ended up writing a very simple periodic HTTP GET scheduler in java using quartz scheduler. It may be useful to other so posting a link to the source on guthub https://github.com/bjordan/simple_java_periodic_HTTP_scheduler
Short explanation:
Main program starts a service process that will stay active in memory and will periodically activate a job – do something.
Create a class that extends System.ServiceProcess.ServiceBase class
Implement at least methods OnStart and OnStop
Start and use Quartz.NET scheduler in OnStart to run tasks periodically
Here is my template C# solution for a Windows service and a Linux demon in .NET/Mono https://github.com/mchudinov/ServiceDemon
And a short blogpost about it
class Program
{
public static void Main(string[] args)
{
ServiceBase[] ServicesToRun;
ServicesToRun = new ServiceBase[] { new ServiceDemon.Service() };
ServiceBase.Run(ServicesToRun);
}
}
public class Service : ServiceBase
{
static IScheduler Scheduler { get; set; }
protected override void OnStart(string[] args)
{
StartScheduler();
StartMyJob();
}
protected override void OnStop()
{
Scheduler.Shutdown();
}
void StartScheduler()
{
ISchedulerFactory schedFact = new StdSchedulerFactory();
Scheduler = schedFact.GetScheduler();
Scheduler.Start();
}
void StartMyJob()
{
var seconds = Int16.Parse(ConfigurationManager.AppSettings["MyJobSeconds"]);
IJobDetail job = JobBuilder.Create<Jobs.MyJob>()
.WithIdentity("MyJob", "group1")
.UsingJobData("Param1", "Hello MyJob!")
.Build();
ITrigger trigger = TriggerBuilder.Create()
.WithIdentity("MyJobTrigger", "group1")
.StartNow()
.WithSimpleSchedule(x => x.WithIntervalInSeconds(seconds).RepeatForever())
.Build();
Scheduler.ScheduleJob(job, trigger);
}
}
public class MyJob : IJob
{
public void Execute(IJobExecutionContext context)
{
JobDataMap dataMap = context.JobDetail.JobDataMap;
log.Info(dataMap["Param1"]);
}
}
Related
I'm using Quarkus. My Quartz jobs are scheduled to run every 10 seconds:
return TriggerBuilder.newTrigger()
.withIdentity("my-job")
.startNow()
.withSchedule(
SimpleScheduleBuilder.simpleSchedule()
.withIntervalInSeconds(10)
.repeatForever()
).build();
This works fine but jobs keep triggering every 10 seconds irrespective of whether or not the last one finishes. I need the next job to start only if there are no jobs currently running job. How do I accomplish this?
Add #DisallowConcurrentExecution on you Job class.
as example :
#DisallowConcurrentExecution
public class MyScheduledJob implements Job {
//execution method
}
I have a task that is potentially long running (hours). The task is performed by multiple workers (AWS ECS instances in my case) that read from a message queue (AWS SQS in my case). I have multiple users adding messages to the queue. The problem is that if Bob adds 5000 messages to the queue, enough to keep the workers busy for 3 days, then Alice comes along and wants to process 5 tasks, Alice will need to wait 3 days before any of Alice's tasks even start.
I would like to feed messages to the workers from Alice and Bob at an equal rate as soon as Alice submits tasks.
I have solved this problem in another context by creating multiple queues (subqueues) for each user (or even each batch a user submits) and alternating between all subqueues when a consumer asks for the next message.
This seems, at least in my world, to be a common problem, and I'm wondering if anyone knows of an established way of solving it.
I don't see any solution with ActiveMQ. I've looked a little at Kafka with it's ability to round-robin partitions in a topic, and that may work. Right now, I'm implementing something using Redis.
I would recommend Cadence Workflow instead of queues as it supports long running operations and state management out of the box.
In your case I would create a workflow instance per user. Every new task would be sent to the user workflow via signal API. Then the workflow instance would queue up the received tasks and execute them one by one.
Here is a outline of the implementation:
public interface SerializedExecutionWorkflow {
#WorkflowMethod
void execute();
#SignalMethod
void addTask(Task t);
}
public interface TaskProcessorActivity {
#ActivityMethod
void process(Task poll);
}
public class SerializedExecutionWorkflowImpl implements SerializedExecutionWorkflow {
private final Queue<Task> taskQueue = new ArrayDeque<>();
private final TaskProcesorActivity processor = Workflow.newActivityStub(TaskProcesorActivity.class);
#Override
public void execute() {
while(!taskQueue.isEmpty()) {
processor.process(taskQueue.poll());
}
}
#Override
public void addTask(Task t) {
taskQueue.add(t);
}
}
And then the code that enqueues that task to the workflow through signal method:
private void addTask(WorkflowClient cadenceClient, Task task) {
// Set workflowId to userId
WorkflowOptions options = new WorkflowOptions.Builder().setWorkflowId(task.getUserId()).build();
// Use workflow interface stub to start/signal workflow instance
SerializedExecutionWorkflow workflow = cadenceClient.newWorkflowStub(SerializedExecutionWorkflow.class, options);
BatchRequest request = cadenceClient.newSignalWithStartRequest();
request.add(workflow::execute);
request.add(workflow::addTask, task);
cadenceClient.signalWithStart(request);
}
Cadence offers a lot of other advantages over using queues for task processing.
Built it exponential retries with unlimited expiration interval
Failure handling. For example it allows to execute a task that notifies another service if both updates couldn't succeed during a configured interval.
Support for long running heartbeating operations
Ability to implement complex task dependencies. For example to implement chaining of calls or compensation logic in case of unrecoverble failures (SAGA)
Gives complete visibility into current state of the update. For example when using queues all you know if there are some messages in a queue and you need additional DB to track the overall progress. With Cadence every event is recorded.
Ability to cancel an update in flight.
See the presentation that goes over Cadence programming model.
I've a method scheduled to run periodically with Spring Scheduler, it's been working fine and stopped working today with no error. What could be the potential cause ? Is there any alternative way to schedule task periodically using Spring Scheduler that ensures that the method will be executed no matter what?
#Scheduled(cron="0 0/1 * * * ?")
public void executePollingFlows(){
if(applicationConfig.isScheduleEnabled()) {
for (long flowId : applicationConfig.getPollingFlowIds()) {
flowService.executeFlow(flowId);
}
logger.info("Finished executing all polling flows at {}", new Date());
}
}
You may have got Out of Memory exception if the job could not finish its tasks but you try to run it again and again. If it is a Out of Memory exception you may try to create a ThreadPool and check it in every run. If there is no enough space in the ThreadPool you can skip the task for this turn.
There is alternative way to use #Scheduled periodically. You may change your #Scheduled annotation with this:
#Scheduled(fixedRate=1000)
It will still be running in every second and if necessary you can add initialDelay to it:
#Scheduled(initialDelay=1000, fixedRate=1000)
You can find more details about fixedRate, initialDelay and fixedDelay here:
https://docs.spring.io/spring/docs/current/spring-framework-reference/html/scheduling.html
Is there a way to limit the lifetime of a running spring-batch job to e.g. 23 hours?
We start a batch job daily by a cron job and he job takes about 9 hours. It happened under some circumstances that the DB connection was so slow that the job took over 60 hours to complete. The problem is that the next job instance gets started by the cronjob the next day - and then anotherone the day after - and anotherone...
If this job is not finished within e.g. 23 hours, I want to terminate it and return an error. Is there a way to do that out-of-the-box with spring-batch?
Using a StepListener you can stop a job by calling StepExecution#setTerminateOnly.
stepBuilderFactory
...
.writer(writer)
.listener(timeoutListener)
...
.build()
And the TimeoutListener could look like this
#Component
public class TimeoutListener implements StepListener {
private StepExecution stepExecution;
#BeforeStep
public void beforeStep(StepExecution stepExecution) {
this.stepExecution = stepExecution;
}
#BeforeRead
public void beforeRead() {
if (jobShouldStop()) {
stepExecution.setTerminateOnly();
}
}
private boolean jobShouldStop() {
// ...
}
}
This will gracefully stop the job, without forcefully terminate any running steps.
Spring Batch specifically avoids the issue of job orchestration which this falls into. That being said, you could add a listener to your job that checks for other instances running and calls stop on them before beginning that one. Not knowing what each job does, I'm not sure how effective that would be, but it should be a start.
If you write your own job class to launch the process you can make your class implement StatefulJob interface, which prevents concurrent launches of the same job. Apart from that you can write your own monitoring and stop the job programatically after some period, but it will require some custom coding, I dont know if there is anything build-in for such use case.
I have a simple viewPart offering some text fields to enter parameters for a selenium test. After filling out these fields the user may start the test which approx. needs 30-45 minutes to run. I want my GUI to be alive during this test giving users the chance to do other things. I need a progress monitor.
I tried to put the selenium test in a job containing Display.getDefault().asyncExec to run it. But my GUI freezes after some seconds giving the busyindicator. The selenium does not update any other view but the progress monitor.
Is there another way to ensure that the job wont block my GUI?
Best,
Mirco
Everything executed in (a)syncExec is using the display thread and therefore blocking your UI until it returns. I suggest you use Eclipse Jobs. This will use the progress indicator that the workbench already offers out of the box.
I would suggest to split your code into code that updates the UI and the code that executes other business. Execute all of it in a separate thread, and when you need to retrieve or set some action to the UI then use the "Display.getDefault().asyncExec".
Thread thread = new Thread("Testing") {
// some shared members
public void run() {
someBusiness();
// or use syncExec if you need your thread
// to wait for the action to finish
Display.getDefault().asyncExec(new Runnable() {
#Override
public void run() {
// UI stuff here
// data retrieval
// values setting
// actions trigging
// but no business
}
});
someBusiness();
};
thread.start();