FAIL OVER

Dec 18, 2014 at 10:32 PM
Hello All,

I use foxpro for back-end data and logic for very long time now. Combined with Ajax, Javascript and CSS ... its so easy and so fast.
I have to be up and running 24/7 ..it's critical. I have so many users online all day long.

But now, I'm facing new challenge. How can I made a FAIL OVER system with foxpro ?

FAIL OVER system is a second computer with the same programs and same data . If the main system crash... the second computer take over in a minute .

I have history files as big as 1.5 gigabytes, for a total of 400 gigabytes of data changing each secound ... so copy over is out of question.

Anybody have experience with this ?

All suggestion are welcome

Bob
Coordinator
Dec 19, 2014 at 6:58 PM
  1. Create a folder in your server (let call it "syncq")
  2. Whenever you add, update or deletes a record in your main database, convert that row to JSON and save it as a text file in syncq folder with an unique name
  3. Insert a new row in a sync table like this:
    INSERT INTO syncQueue (stamp, operation, data, status) VALUES (DATETIME(), "ADD / UPD / DROP", cJSONData, "PENDING")
  4. Create a process that check the queue every 15s or so and reads any rows with status PENDING and perform the operation in the fail over database, marking the row as PROCESSED
Victor