I need to update camel quartz cron based timer dynamically on runtime.
The timer cron expression is mentioned in DB and accordingly my scheduler is working and suppose it is 10 minutes interval.
Now if I update timer cron expression in DB(updated to 20 minutes interval), I am trying to update the cron expression in camel side which should run 20 minutes interval instead of 10 mins interval but not reflecting.
I have gone through couple of links but could not get much help:
Camel runtime timer change
https://issues.apache.org/jira/browse/CAMEL-7153
Any guidance or example will be great to understand. Advance thanks.
If Camel does not provide such solution, which library will be best suitable for such use case. I have few in minds like (Java Timer, Spring Scheduler, Quartz Scheduler) and I feel these provides such provision.
Related
Can anybody help me with scheduling cron jobs with a help of Hazelcast? I know that Hazelcast has IScheduledExecutorService, but I can't find a way to schedule cron task (only delayed or interval jobs).
Hazelcast doesn't have that kind of functionality. You need to use a 3rd party system like quartz scheduler.
I am trying to implement a quartz scheduler which should run every n days.
Say I wrote a trigger which runs every 10 days. If I restart my server on 9th day, the cron jobs will be reloaded based on current time. So it won't fire on the 10th day instead it will fire on 19th day.
Is there any way we to trigger jobs based on last run date so that it will trigger on 10th day.
If you "just" have to remember your job executions, you have to persist it in some way. An approach with minimum impact would be using something like a Quartz JDBCJobStore.
Maybe you are already using Spring and in case you need a more "sophisticated" (single steps, start & stop & restart) way take a look at Spring Batch.
For a system monitoring Java application which currently runs on the command line and uses ScheduledExecutorService, I would like to write a simple web application version, to be run in a Servlet container like Apache Tomcat or Eclipse Jetty.
I have read about Quartz as one of the popular job schedulers for web applications. Would it be better (maybe because of better servlet container integration) to port this application from ScheduledExecutorService to Quartz?
Adding another library dependency to the application is not a problem, I am interested in technical reasons against usage of ScheduledExecutorService.
It depends on what you are using it for.
Quartz is useful for programmed times e.g. every hour on the hour.
ScheduledExecutorService is useful for repeating tasks which don't have to occur at a specific time. Its simpler and possibly more efficient. If you have this working it indicates to me that you don't need Quartz.
ScheduledExecutorService operates at a lower level and you'd have to implement all scheduling monitoring/maintenance facilities yourself.
Quartz has tons of facilities such as Job Persistence, Transactions, Clustering etc.
Java's Executor solution allows you to either:
immediately run a task
start a task after an initial delay (and optionally rerun the task after subsequent delay cycles).
But Quartz empowers you with incredible flexibility on when and how often to run a task/job. For example, one schedule during the Mon-Fri work week and something else (or not at all) during the weekends. Or on the last day of the month and you don't have to figure out if a given month's last day is on the 28th, 29th, 30th, or 31st. Here's some more examples of the flexibility the cron style scheduling accommodates - http://www.quartz-scheduler.org/documentation/quartz-2.x/tutorials/crontrigger.html#examples
Using Java's library is easier but for anyone that wants a jump start into a bare-bones codebase example of Quartz working, I've put this template together for free download usage - https://github.com/javateer/quartz-example
I'm making a program for my own use.
In this program, I need to set up cron job. The cron job should run every minute (24 hr * 60 mins = 1440 times). Thus, I'll need to set up a cron job with a frequency of 1 minute.
I think Google App Engine gives free cron job. But I'm very new to it. I downloaded the java SDK and read the document but understood nothing :( So, I can't use Google App Engine.
Is here any other free service like Google app engine which but with easier inferface???
All I want is a cron job with 1 minute frequency
Please help/suggest me...
Thank you
Just install linux.
If this is a java app, then you can use Quartz, right? This way you can control what to do when the job fails (like cleaning up certain resources, sending emails, etc).
Maybe you want to use a service like setcronjob.com.
This lets you specify a URL that will be triggered periodically (according to the cron pattern you choose).
Of course, you still need to have a server somewhere to host the URL and implement the actual task there.
You can do this in App Engine - see the cron docs for details. In order to provide any more specific help, we'd need to know what you want that cron job to do, precisely.
I had the similar need. Ended up testing a whole bunch of scheduling services. Check out cronservice.co.uk/new/,
setcronjob.com or mywebcron.com. I ended up using the scheduler.codeeffects.com because of their set of features and the interface. Google for others, there are tons services like this. Most are free or give free stuff. Sorry for the late reply, but I thought this might help.
To schedule a job in Java, use cron.xml
Python uses the more terse cron.yaml format.
In both cases, it's actually quite easy to use, you can schedule jobs, with the following actual description and Google App Engine will understand what it means:
every 12 hours
every 5 minutes from 10:00 to 14:00
2nd,third mon,wed,thu of march 17:00
every monday 09:00
1st monday of sep,oct,nov 17:00
every day 00:00
I'm looking for an effective way to execute a method everyday at 3PM regardless of when the application was initially run or how long it has been running.
This must be done entirely from the application with no OS intervention (ex. Windows Task Scheduler)
I have been experimenting with java.util.Timer in varies configurations but I have had no success.
Any help would be appreciated.
Thanks.
You should take a look at Quartz which is a Java-based job scheduling system.
You will probably want to use something like the quartz engine it can do things like execute tasks that missed (like during a ahem crash) and it takes the work out of trying to manage threads.
For example if you use threads and put it to sleep and wake it up 86400 seconds (one day) later you will wake up and hour late (day = 82800 seconds) or early (day = 90000 seconds) on DST change over day, so be careful with whatever solution you choose
A built-in JDK way is to do what others suggested and first calculate :
currentTime - desiredTime
Then you can use something like a schedule executor to submit the tasks, and run them with a particular delay. This is far simpler than the options you have with frameworks like Quartz, but doesn't require an external dependency.
Also, you should always list which JDK you're using, so people can provide solutions for your version of the JDK.
You can start a thread that calculates the difference to the next 3pm and sleeps for that time. When it wakes up it executes the method and recalculates and sleeps. Is this what you meant?
As stated by others Quartz is a choice, with it you can do cron-like operations, jobs or triggers, here is a link on this subject: http://www.ibm.com/developerworks/java/library/j-quartz/index.html
Jcrontab
Jcrontab is a scheduler written in Java. The project objective is to provide a fully functional schedules for Java projects.