symphony

scheduler Stepper

Idea

A way to reduce the cost of calculating nexttime of all jobs.

Before:

Use SQL, may be SELECT JobId, JobName, JobNextTime, JobAction, IsFinished from Jobs where JobNextTime < 123456789 and JobNextTime > 12345, to find all jobs those need to run EVERY STEP (calculate all nexttime in database every step.).

Then ask worker to execute the jobs.

Now:

Use SQL too, but cache the job into a STEPs Calendar.

For example: 30 second per Step:

0 : Job1, Job2, Job3, Job4...
30: Job5, Job10 ...
60: Job6, Job7 ...
90:
120: Job8...

when the STEP on an index, then execute the jobs in Calendar, No need to run SQL EVERY STEP.

BUT! the Jobs Updating in DATABASE must be synced to the Calendar.

However, Use the Memory to exchange CPU (Maybe include Network IO/DataBase Memory/DataBase Space).