READ-COMMITTED isolation level for Camunda

Camunda 7 Topics Discussion & Questions
1

I was using camunda spring boot starters in micro service running as process application.

Database version is AWS RDS - MySQL 5.7.17 (Innodb).

As per docs, and camunda workflows are tested in READ-COMMITTED isolation level which is recommended to set for camunda usecases.

But REPEATABLE-READ was default isolation level in MySQL.

So i was trying to set isolation level to READ-COMMITTED globally.

With superuser previleges, i executed below query to set recommended isolation level:

SET GLOBAL tx_isolation='READ-COMMITTED';

To check whether isolation level was set, executed below query,

image

Also executed below query and got different results:

image

How can i ensure that my application was running with READ_COMMITTED isolation level?

2

Hi,

I am not mysql expert, but I guess you need to set the session isolation explicitly:

SET SESSION tx_isolation='READ-COMMITTED'

not only the global configuration.

3

Thanks @Yana,

I tried this. It will set isolation for current session.

Whenever application connects to database, new session will be created, that will pointing to default Isolation level of MySQL(REPEATBALE READ).

I want to set it programmatically to all sessions.

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4

I was able to set ISOLATION LEVEL programmatically using apache commons dpc2 connection pooling.

   BasicDataSource dataSource = new BasicDataSource();        
    dataSource.setPoolPreparedStatements(true);
    dataSource.setMaxOpenPreparedStatements(20);
    dataSource.setDefaultTransactionIsolation(2);
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