Vnode Attribute Names and Values
Valid vnode attribute names and values are as follows:
connection_type
Indicates how the connection is to be established type. The attributed can be abbreviated as conn_type. Valid values are:
default
Establishes a standard connection. In general, this means the connection is established between the client application process and the remote instance using the Net protocol.
comsvr
Establishes the connection using the Communications Server in the local instance, where it is then routed across the network.
direct
Establishes a direct connection with the server in the remote instance without using Net. This attribute improves performance because data goes directly from the application process on the client machine to the DBMS process on the server machine, thus bypassing Communications Server processing, except for initial connection setup.
For direct access to occur, the following conditions must be met:
• The client and server machines must be the same platform type (for example, both Windows, or both Solaris, or Windows to Linux on Intel-based machines) and the environment variable II_CHARSET must be identical on both the client and server machines.
• The same network protocol must be used for the local IPC on the client and server machines.
• On Windows, the client and server machines must be logged into the same Windows network domain if using (default) named pipes for local IPC.
• Ingres II 2.5 or higher must be installed on both the client and server machines.
• On any platform which uses the IPC protocol for local and network connections, the environment variable, II_GC_REMOTE must be set (for the DBMS Server instance) to ON or ENABLED to allow direct connections. For important information on network security and II_GC_REMOTE, see the Ingres System Administrator Guide.
• Between Windows and Linux, II_GC_PROT is set to tcp_ip on Windows, and the Linux system is running TCP/IP for its local protocol.
Note: II_GC_PROT should be changed only when Ingres (including tools such as IVM) is completely shut down; otherwise, failures will occur for Ingres shutdown, startup, and connection requests.
• A client installation should not be at a higher major release level than the Ingres server. While this is not a requirement across all releases of Ingres, Ingres 10 clients specifically are not supported for direct access to pre-Ingres 10 servers; connection attempts will likely hang. The reverse configuration works: An older release Ingres client can directly access a newer release Ingres server.
encryption_mode
Specifies the encryption mode for the connection. If set, this value overrides the Communications Server’s ob_encrypt_mode parameter value configured using Configuration Manager or the Configuration-By-Forms utility. The local and remote Communications Servers must be able to negotiate a common mechanism to perform the encryption.
The attribute can be abbreviated as emode.
Valid values are:
off
(Default) No encryption. The connection fails if the remote Communications Server encryption mode is ON.
optional
Encryption occurs if the remote Communications Server encryption mode is PREFERRED or ON and a compatible encryption mechanism is available. Abbreviation: opt
preferred
Encryption occurs if a compatible encryption mechanism is available unless the remote Communications Server encryption mode is OFF. No warning is given if encryption is not possible. Abbreviation: pre
on
Encryption occurs unless no compatible encryption mechanism is available or if the remote Communications Server encryption mode is OFF. Connection fails if encryption is not possible.
Note: The ON setting replaces REQUIRED, which is deprecated, but available for backward compatibility.
encryption_mechanism
Specifies the mechanism to be used to encrypt the remote connection. If set, this value overrides the Communications Server’s ob_encrypt_mech parameter value configured using Configuration Manager or the Configuration-By-Forms utility. The attribute can be abbreviated as emech. Valid values are:
none – Disables encryption
* – Allows all encryption mechanisms to be considered during Communications Server negotiations
mechanism_name – Indicates a specific mechanism to be considered during Communications Server negotiations
compression_type
Specifies the compression type to be used on the connection. Only a single compression type is supported, so current values simply allow compression to be enabled or disabled. Abbreviation: compress. Valid values are:
none – Disables compression
off – Disables compression
default – Enables compression using the default compression type
on – Enables compression using the default compression type
authentication_mechanism
Specifies the mechanism to be used for remote authentication in a distributed security environment. This setting replaces the need for a user ID and password. If set, this value overrides the Communications Server’s remote_mechanism parameter value configured using Configuration Manager or the Configuration-By-Forms utility. The only valid value is kerberos.
character_set
Specifies the character set used on the remote instance. This attribute is necessary when connecting a UTF8 configured client instance with an older version remote instance that is not configured as UTF8 and the connection cannot be established because a common communication character set cannot be negotiated. The attribute can be abbreviated as charset. Valid values are any character set names that can be used in the II_CHARSET environment variable.