Consultor Eletrônico

Status: Verified

GOAL:

How to Use Progress on a TCP/IP Network

FIX:

The use of a TCP/IP network distributes the processing load among multiple machines on the network. This allows you to use a less powerful server machine than a machine with the same number of local or direct access clients.

Each machine on the network must have a unique network address and hostname.

On UNIX machines, these are maintained in the /etc/hosts file. The file also contains the internet address and the hostname. For example:

 # /etc/hosts
 127.0.0.1      localhost loopback lb loop
 192.9.211.99   tsserv tsserv-e0
 198.137.64.1   misseq

NOTE: You must be sure to have a copy of the /etc/hosts file on the client machine also. These entries are case-sensitive.

The machine on which the database resides must also have a file that contains the services that it can provide to the network. This file is called /etc/services, and contains the service name as well as unique service numbers and protocol type. For example:

 # /etc/services
 monitor     561/udp
 demosv      2500/tcp
 demosv1     2501/tcp
 demosv2     2502/tcp

NOTE: You must have a copy of the /etc/services file on the client that has identical service entries. These entries are case-sensitive.

The last file that needs to be present is the /etc/protocols file. This file contains the protocol types and unique protocol numbers. For example:

 # /etc/protocols
 ip     0 IP
 icmp   1 ICMP
 ggp    3 GGP
 tcp    6 TCP
 pup    12 PUP
 udp    17 UDP

This file should be provided by the operating system or network library manufacturer. You should not have to edit this file.

After the above-mentioned files are set up, you must test the connection. You can use the "ping" command:

 ping <hostname>.

There are additional options with the ping command, but they are generally not needed in order to determine whether you have reached another host on the network. The ping command should generally return information about packets that are transmitted and received.

Before you start a Progress broker and remote servers:

Be aware of the following Progress startup options. The most important networking options are:

 -N  - Network type (eg. TCP, TLI, NETBIOS,...)
 -H  - Host Name (same name as /etc/hosts)
 -S  - Service Name (same as /etc/services)
 -Mn - Maximum number of servers
 -Mi - Minimum number of clients per server
 -Ma - Maximum number of clients per server

(For a detailed description of these and other startup options, please check the references to written documentation at the end of this solution.)

Use the following command to start the Progress broker in a networked environment:

 proserve <dbname> -S <servicename> (other options)

Substitute the actual names for <dbname> and <servicename>.

The command starts the broker and tells the broker to "listen" for remote users. You can have four remote servers by default with a minimum of one client per server and a maximum of five clients per server. You can modify these values with the-Mn, -Mi, and -Ma startup options.

NOTE: You do not need the -H parameter because you execute this command on the host machine.

Use the following command to start remote clients:

 mpro <dbname> -H <hostname> -S <servicename> (other options)

To start local clients, use:

 mpro <dbname> (other options)