CHAPTER 5: Distributed Server Set Up




5.1 Empress Distributed Server Set Up

Setting up the Empress Distributed Server consists of three steps:

  1. Setting up the Global Data Dictionary on the client machine.

  2. Setting up the Server Configuration File on the client and server machines.

  3. Starting the server on the server machine.

For example, to set up a Distributed Server with the following configuration:

5.1.1 Setting Up the Global Data Dictionary

The Global Data Dictionary, which must be set up on the client (local) machine, is an ASCII file and is created by running the Empress utility program empsvutl with the syntax:

empsvutl -gdd GDD

where:

GDD is the name of the Global Data Dictionary file which can be any filename.

Empress responds with the following:

Logical Database name <hit return to quit> :logicaldb1

Full path name of the Database in the Server machine (e.g. /usr/empress/db_name) > /usr/database/db1

Distributed Server name [LOCAL] : srv1

Logical Database name :   logicaldb1
Physical Database path name : /usr/database/db1
Distributed Server name :   srv1

Is this correct (y/n/q) ? y

Logical Database name <hit return to quit> :

In this example the Global Data Dictionary is named GDD and resides in /usr/dbadmin.

The contents of the file are as follows:

MSDBLOGICALNAME=logicaldb1
   MSDBLOCATION=/usr/databases/db1
   MSDBSERVERNAME=srv1
MSDBLOGICALEND

Set the Empress environment variable MSGLOBALDATADICTIONARY to indicate the location of the Global Data Dictionary.

For example, in the UNIX C shell:

setenv MSGLOBALDATADICTIONARY /usr/dbadmin/GDD

or in the UNIX Bourne or Korn shell:

MSGLOBALDATADICTIONARY=/usr/dbadmin/GDD
export MSGLOBALDATADICTIONARY

5.1.2 Setting Up the Server Configuration File

The Server Configuration File is an ASCII file and is created by running the Empress utility program empsvutl with the syntax:

empsvutl -scf SCF

SCF is the name of the Server Configuration File which can be any file name.

Empress responds with the following:

Distributed Server name <hit return to quit> : srv1

Node name of the machine where Server resides: > copper

Number of Server sub-processes [1] :
Name of Server administrator [support] : joe

Note that : No two active Servers can have the same combination
            of host name an Internet port number
Internet port number (5000 - 65534) : 5001
Distributed Server name : srv1
Server host name : copper
Number of Server sub-processes : 1
Name of Server administrator : joe
Network access type : INET_SOCKET
Internet port number : 5001

Is this correct (y/n/q) ? y

Distributed Server name <hit return to quit> :

For the purpose of this example, we will use the name SCF and place the file in the directory /usr/dbadmin. The contents of the file are as follows:

MSSERVERNAME=srv1
   MSSERVERHOSTNAME=copper
   MSSERVERNPROCS=1
   MSSERVERADMINISTRATOR=joe
   MSSERVERNETTYPE=INET_SOCKET
      MSINETPORT=5001
MSSERVEREND

Set the Empress environment variable MSSERVERCONFIGFILE to indicate the location of the Server Configuration File on the server machine.

In the UNIX C shell:

setenv MSSERVERCONFIGFILE /usr/dbadmin/SCF

or in the UNIX Bourne or Korn shell:

MSSERVERCONFIGFILE=/usr/dbadmin/SCF
export MSSERVERCONFIGFILE

Follow the same procedure to set up the Server Configuration File and the environment variable on the client machine. Ideally, copy the file from the server machine to the client. This will guarantee that the files are identical.

5.1.3 Starting the Server

The Empress utility empsv is used from the server machine to start the Distributed Server. The syntax is as follows:

empsv server_name

where:

server_name is the name of the server which is defined in the Server Configuration File.

In our example, we start the server by typing the command:

empsv srv1

The server must reside on the same machine as the database it will service. The server must be started from the machine where it will run. The variable MSSERVERCONFIGFILE must be set before this command is run so that the server can find its configuration file when it starts.

There should be one process for each server sub-process as specified by MSSERVERNPROCS within the Server Configuration File. There will be one extra process for the server spooler-scheduler.