I want to create a timer job that will be on all of SharePoint's web applications.
It's not a problem - but I'm thinking of the situation when a new web application is created.
Will my timer job be automatically provisioned on that web application as well?
If not, How can I create a timer job that does?
It's all about in the way you construct your Feature receiver. Simply create a Web Application scoped feature, which is automatically activated (set this in VS already in the Properties window). In this you would put something like that:
SPWebApplication webApp = properties.Feature.Parent as SPWebApplication;
//Add code to check whether it is already added and Remove it 1st.
DeleteJob(webApp.JobDefinitions);
MyJobDefinition myJob = new MyJobDefinition(webApp);
//set schedule and other properties and then run Update
myJob.Update();
Which constructor you choose is important, because beyond the WebApplication you would also have to consider "where" (on which server it runs - Central Admin by default, or specifically Front Ends..etc., i believe this examples would help http://www.martinhatch.com/2009/08/sharepoint-timer-jobs-and-multiple.html).
Not sure if you've gone through this article, as a comprehensive guide http://www.simple-talk.com/dotnet/.net-tools/a-complete-guide-to-writing-timer-jobs-in-sharepoint-2010/
