Springboot starter - MySQL Isolation Level

Camunda 7 Topics Discussion & Questions
1

Does using camunda springboot starter already set transaction isolation level to READ COMMITED?

If i use mysql workbench to conenct to my database and execute:
SELECT @@global.tx_isolation

it shows me “REPEATABLE-READ”. Do I need to change it globally or camunda already set it when opening a new transaction?

2

@Jean_Robert_Alves you have to set it to globally to READ_COMMITTED as isolation level for MySQL. Camunda doesn’t change any of the db configurations.

  • The Isolation level’s can be set globally or session based on our requirements.

  • A change to global transaction characteristics requires the CONNECTION_ADMIN or SUPER privilege. Any session is free to change its session characteristics (even in the middle of a transaction), or the characteristics for its next transaction (prior to the start of that transaction).

  • To set the global isolation level at server startup, use the --transaction-isolation=level option on the command line or in an option file. Values of level for this option use dashes rather than spaces, so the permissible values are READ-UNCOMMITTED , READ-COMMITTED , REPEATABLE-READ , or SERIALIZABLE .

  • Similarly, to set the global transaction access mode at server startup, use the --transaction-read-only option. The default is OFF (read/write mode) but the value can be set to ON for a mode of read only.

SET [GLOBAL | SESSION] TRANSACTION
    transaction_characteristic [, transaction_characteristic] ...

transaction_characteristic: {
    ISOLATION LEVEL level
  | access_mode
}

level: {
     REPEATABLE READ
   | READ COMMITTED
   | READ UNCOMMITTED
   | SERIALIZABLE
}

access_mode: {
     READ WRITE
   | READ ONLY
}

For camunda we need isolation level as ,
SET GLOBAL TRANSACTION ISOLATION LEVEL READ COMMITTED;

Then run the below query:
SELECT @@GLOBAL.transaction_isolation, @@GLOBAL.transaction_read_only;

1 Like
3