The FAQs about the main features of Atlas

1. Does Atlas support multiple character sets?

Yes, you can set charset through the config option(charset) in config file.

2. Does Atlas support database transaction?

Yes, if the mysql client is in a transaction and quit unexpectedly, Atlas will destory the connection and rollback the transaction, assure ACID of the transaction.

3.Atlas can split reading/writing requests, but sometimes I want send the reading requests to master and don't use transaction. How can I do?

You can add a comment('/*master*/') in the head of the sql, like '/*master*/select * from stu;',and this sql will send to the master.When you use mysql client to test this function, you need use the parameter:'-c' to connect the mysql server in order to retain the comment.

4.If the master is down, the slave also can read in Atlas?

Yes, when the master crash, the reading request will be forward to the slaves by Atlas. The execution of the writing requests will fail, because the master is down.

5.How does Atlas detect the status of the backend database server.

Atlas will create a thread in order to detect the status of the backend database server in a round robin manner. The working thread will not be influenced.

6.When I want make a database offline, and I don't want shut the mysql server down.How can I do ?

You can make the database offline(online) through the admin interface of Atlas.You can also add(remove) a backend through the admin interface.

7.Does Atlas support prepare statement using in mysql?

Atlas support prepare statement limited, supporting java, python, PHP(PDO mode).

8.Does Atlas support Multi-Master mode ?

Currently Atlas do not support this mode, because in this mode Atlas can't assure the data consistency. Atlas support the modes like: a master and a slave, a master and multi-slaves.

9.When I use jdbc to connect Atlas, the chinese characters in application often garble, why ?

You should modify the connection mode of jdbc. For example:

jdbc:mysql://10.10.10.37:3306/user_db?useUnicode=true&characterEncoding=utf-8&autoReconnect=true 

change to

jdbc:mysql://10.10.10.37:3306/user_db?useUnicode=true&characterEncoding=utf-8&autoReconnect=true 

10.Does Atlas monitor the master-slave log file syncing ?

No, Atlas doesn't monitor the master-slave log file syncing. But enthusiastic user has used perl to implement this function.If you are interested in his implementation, you can visit:

https://github.com/chenzhe07/Atlas_auto_setline

11.When the application developed by java connect Atlas, sometimes the read requests are forwarded to the master,why?

One reason is autocommit is 0, you should change the autocommit to 1.