Connect multiple MySQL server using JDBC Java

Question

I have 10 different MySQL servers with the same schema design. Now I have to query each server and merge results in java which is same as UNION ALL in SQL.

All DB servers return the same data format, and I tried sequential call of all server but it takes more time.

How can I speed up the process?

Scenario

Answer 1

This probably your sequential logic:

1. List<YourObject> arr = new ArrayList<YourObject>();
2. X = 1.
3. Select * from X.
4. add results to arr.
5. X++ until no more databases.

I can think of a solution that might consume less time:

How about this logic:

you can cut the sequential into threads. each thread will connect to a different server. once you have result from a server lock the arr and add the results.

1. Create a Connection thread to each Server.
2. Run Threads to connect and wait for result.
3. Each incoming result add to a merged array. (don't forget to lock global result array).