Configuring the Data Access Server
Data Access Server
The Data Access Server (DAS) process (iigcd) is a component of the General Communications Architecture (GCA) and runs as part of a standard Vector instance.
The server translates JDBC or .NET Data Provider requests from the JDBC Driver or the .NET Data Provider into Ingres or Vector internal format and forwards the request to the appropriate DBMS server. The DAS supports the same network protocols and port designations as the Communications Server.
Through the DAS, a JDBC or .NET Data Provider client has full access to Ingres, Vector, Enterprise Access, and EDBC databases. Using Net, the DAS can also provide JDBC or .NET Data Provider clients with access to these databases on remote machines.
Data Access Server Parameters--Configure DAS
To configure the DAS, use the Data Access Server Parameters page in Configuration-By-Forms (cbf) or Configuration Manager (vcbf).
The DAS has the following configurable parameters:
client_max
Defines the maximum number of concurrent client connections permitted.
Set to –1 for no limit.
client_timeout
Defines the time, in minutes, to wait for client requests. If the time expires with no request from the client, the client and DBMS Server connections are aborted.
Set to 0 for no timeout.
connect_pool_expire
Defines the time, in minutes, for which a DBMS Server connection remains in the connection pool. The connection is aborted if a pooled connection is not used in this amount of time.
Set to 0 for no expiration.
connect_pool_size
Defines the maximum number of DBMS Server connections held in the connection pool.
Set to –1 for no limit.
connect_pool_status
Specifies the operational mode of the connection pool. Modes are:
on
Enables pooling unless explicitly disabled by the client. The DAS saves and reuses DBMS Server connections when connection pooling is enabled.
off
Disables pooling.
optional
Enables pooling but only when requested by the client.
<protocol>.port
Identifies the listen address for the network protocol port. This can be a numeric port identifier or a symbolic port identifier such as II7. This port must not be used by any other network server on the platform.
The symbolic port ID has the following syntax:
XY{n}{+}
where
• X is an alphabetic character
• Y is an alphanumeric character
• n is a subport in the range 0 to 15. A leading 0 is permitted in the subport (for example: II09 is interpreted as II9).
• + indicates that a port ID can be rolled up.
If the DAS startup count is specified as greater than 1, CBF automatically adds a + designator to the port identifier. When listen attempts are made on such a port identifier, the address is incremented (rolled up) and a listen attempt is made on the next address. This allows for connection attempts to multiple Data Access Servers.
Ingres default: II7
Vector default: VW7
<protocol>.status
Specifies the status of the network protocol. Options are:
on
Indicates that the DAS must listen to (accept) connection requests on the protocol.
off
Disables the protocol.
How You Enable Data Access Server Tracing
As a GCA-based server, the DAS (iigcd) is a companion to the Name Server (iigcn) and the Communications Server (iigcc), and supports GCA tracing and other similar module tracing.
To enable DAS tracing, use any of these methods:
• Add entries to the Ingres configuration file (config.dat) in the gcd section. This method is preferred because it allows trace output from multiple servers to be logged in the same file.
• Set the environment variables prior to starting the server.
• Enable tracing dynamically by using the iimonitor set trace command. This command overrides trace settings in the config.dat and environment variables. For details, see the iimonitor set trace command in the “Command Reference” chapter in the User Guide.
As a general rule, use the config.dat file for server tracing and the environment variables for client tracing.
The entries or values you must supply are as follows:
Tracing Levels
The tracing level determines the type of information that is logged. The following levels are currently defined:
1 – Errors and exceptions
2 – High level method invocation
3 – High level method details
4 – Low level method invocation
5 – Low level method details
6 – Low level method verbose details
Set DAS Tracing
To set both GCD and GCA tracing for the DAS in the configuration file to detailed levels of tracing
1. Issue the following commands, replacing machine with the appropriate machine name:
iisetres ii.machine.gcd.*.gcd_trace_log /tmp/gcd.log
iisetres ii.machine.gcd.*.gcd_trace_level 5
iisetres ii.machine.gcd.*.gca_trace_level 5
2. Recycle the DAS to start tracing. You can recycle the DAS only (instead of the entire installation) by issuing these commands:
ingstop -iigcd
ingstart -iigcd
To remove the trace entries and stop tracing
Issue the following commands, and then recycle the DAS:
iiremres ii.machine.gcd.*.gcd_trace_log
iiremres ii.machine.gcd.*.gcd_trace_level
iiremres ii.machine.gcd.*.gca_trace_level