When configuring Tungsten Connector it is important to ensure that you have
user.map in place. The role of
user.map is to define the usernames and passwords of
users that will be connecting to the dataserver.
There is no authentication within the connector. Instead, the connector
sends authentication information onto the dataserver. However, the MySQL
network protocol exchanges a token between the client and the dataserver
in order to authenticate the connection and is designed to prevent 'man in
the middle' attacks.
Unfortunately, 'man in the middle' is exactly how Tungsten Connector
operates, as the man in the middle to redirect queries to different
dataservers as the list of active dataservers changes during the operation
of a cluster. The authentication exchange cannot be reinitiated by the
dataserver and client, so the Tungsten Connector performs this
authentication exchange on behalf of the client using the user and
password information from a special file called
Figure 6.8. Tungsten Connector Authentication
To get round this limitation, the connector operates as follows:
Client opens a connection to the connector and authenticates.
Connector connects to the datasource using the username supplied by
the client, and the corresponding password stored within
Database server returns the authentication token to the connector.
Connectors sends the same authentication token back to the client.
This process gives the client application the authentication token
required to enable it to communicate with the dataserver and the same
token to be used by the connector.
For this system to work, a file,
user.map, must exist
on every connector installation, and it must contain the information for
all users that will connect to the datasources from each client. Without
this information, connectors will be unable to login on behalf of the
All the users that require access to your MySQL servers through the
Tungsten Connector must have an entry in the
user.map. Without this information, the
Tungsten Connector has no way of providing an onward connection to a MySQL
user.map file primary role is to operate as the
source for authentication information within the connector. However,
through the use of additional flags and keywords, the file can also define
the routing methods used by different users when connecting to
datasources, and different dataservices.