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5.3. QAD GRID PLATFORM SERVER 115
Figure 5.3.3: A user’s perspective sequence diagram of the processes started when
a task is scheduled or a worker started.
authentication 9 schema where two different methods are used to authenticate.
Using more than one factor is supposed to be a strong authentication opposed
to a weak authentication when only one factor (such as a password) is used.
Authentication in the QAD Grid is needed in three situations: (a) when
a server wants to start a worker (this is operating system dependent and
explained in section 5.3.3), (b) when a worker tries to connect to the Grid
platform server, or (c) when a user wants to connect to the Grid server. For
a worker to be able to connect to the Grid it must first register at the Grid
platform server. This process is described in more details in section 5.4.2.
After a successful registration process
� a database account has been created for this worker at the database
server,
� the account information (user id and password) were sent to the worker,
� a new RSA public/private key pair for this worker was issued and transferred
to the worker,
� a new worker certificate was issued and transferred to the worker.
Note, that transmission/communication of sensitive data is encrypted (see
section 5.3.1).
The authentication process is as follows:
1. The worker sends its certificate and account information to the server.
This is done through a database account that has only write access to
the connection initiation table in the database. The worker then inserts
its certificate into the table by calling a stored procedure 10 . Further
9 An authentication factor is a piece of information.
10 A stored procedure is a subroutine available to applications accessing a relational
database system. Stored procedures are actually stored in the database. Typical uses for