使用mysqldump从实时站点中的其他数据库导入MySQL表会引起麻烦吗？

Question

Scenario: I want to replicate MySQL tables from one database to other database.

Possible best solution: May be to use MySQL Replication feature. Current solution on what I'm working as workaround (mysqldump) because can't spend time to learn about Replication in current deadline.

So currently I'm using command like this:

mysqldump -u user1 -ppassword1 --single-transaction SourceDb TblName | mysql -u user2 -ppassword2 DestinationDB

Based on some tests, it seems to be working fine. While running above command, I run ab command with 1000 requests on destination site and tried accessing the site from browser also.

My concern is for destination live site on which we are importing data with whole table (which will internally drop existing table and create new one with new data).

Can I be sure that live site won't break while this process or is there any risk factor? If yes then can that be resolved?

Answer 1

As such you already admitted replication is the best solution here, I'd agree to that.

You said you have 1000 requests on "Destination" side? Are these 1000 connections to Destination read-only? Ofcourse dropping and recreating table isn't a right choice here for active connections.

Can suggest one improvement. Instead of directly loading to table, load to different database and swap tables. This should be quicker as far as connections to Destination database/tables are concerned.

• create new table different database

mysqldump -u user1 -ppassword1 --single-transaction -hSOURCE_HOST SourceDb TblName | mysql -uuser2 -ppassword2 -hDESTINATION_HOST DB_New

(Are you sure you don't have "-h " here?)

• Swap the tables

rename table DB.TblName to DB.old_TblName, DB_New.new_TblName to DestinationDB.TblName;

If you're on same host (which I dont think so), you might want to use pt-online-schema-change and swap tables!