Spring+Hibernate: read/write different datasource and thousands mysql databases

问题

I need to use separate reader/writer MySQL servers. One writer and one (or more) read replica.

What is the best way to do this?

I found a lot of examples:

http://www.dragishak.com/?p=307

Use special JDBC driver: com.mysql.jdbc.ReplicationDriver

And usage is:

@Transactional(readOnly=true)
@ReadOnlyConnection
public Result serviceMethod(…) {
   …
}

https://stackoverflow.com/a/33169879/1974494

Using Spring AbstractRoutingDatasource:

Usage:

@Transactional(readOnly = true)
public Page<BookDTO> getBooks(Pageable p) {
  try{
    DbContextHolder.setDbType(DbType.REPLICA1);   // <----- set ThreadLocal DataSource lookup key

In each method I need to set DbType.

Is possible to automatically send "read query" to replica server and "write query" (insert/update) to master server?

And second question:

I would like to have one mysql database per user (very big). I expect about 2 000 users. So I cannot define datasource for each users * reader+writer.

Example:

spring.ds_items.driverClassName=com.mysql.jdbc.Driver
spring.ds_items.url=jdbc:mysql://mysql-master/user1
spring.ds_items.username=root 
spring.ds_items.password=12345

spring.ds_items.driverClassName=com.mysql.jdbc.Driver
spring.ds_items.url=jdbc:mysql://mysql-replica1/user1
spring.ds_items.username=root 
spring.ds_items.password=12345

spring.ds_items.driverClassName=com.mysql.jdbc.Driver
spring.ds_items.url=jdbc:mysql://mysql-master/user2
spring.ds_items.username=root 
spring.ds_items.password=12345

spring.ds_items.driverClassName=com.mysql.jdbc.Driver
spring.ds_items.url=jdbc:mysql://mysql-replica1/user2
spring.ds_items.username=root 
spring.ds_items.password=12345

I would like to have one "main mysql database" with table something like:

user   db_name
--------------
test1  db_test1
test2  db_test2

And if I need some data for user test2 I look at "main database" and get info for database db_test2 to use. After that send query to database db_test2.

回答1:

The Best Way is to use MySQL Connector/J replication aware driver configuration . Your Connection string will be as below

jdbc:mysql:replication://[master host][:port],[slave host 1][:port][,[slave host 2][:port]]...[/[database]]

Once you tag a transaction as read only , it will be automatically routed to read only slaves

https://dev.mysql.com/doc/connector-j/5.1/en/connector-j-master-slave-replication-connection.html

来源：https://stackoverflow.com/questions/43324861/springhibernate-read-write-different-datasource-and-thousands-mysql-databases

标签

java

mysql

Spring

hibernate

database-replication