The Service Directory Maintenance function is used to maintain a service directory in order to connect the client's calling program to a subprogram on a server.
The service directory information is stored in the NATCLTGS
subprogram in the library that is defined with the profile parameter
RPCSDIR
(see the Parameter Reference documentation). If
RPCSDIR is set, the Service Directory
Maintenance function references the library specified with
RPCSDIR. If RPCSDIR is not set
(this is the default), the library where you are logged on is referenced. In
this case, log on to the library (or one of its steplibs) used by the client at
runtime before you perform the Service Directory
Maintenance function.
The name of the library referenced for service directory
maintenance is indicated in the upper right corner of the
Service
Directory screen (see Invoking Service Directory
Maintenance). If RPCSDIR is set, the screen
title contains Central, which indicates that the library
displayed on the screen is not the library where you are currently
logged on, but the central library specified with
RPCSDIR.
If NATCLTGS is stored in the Natural system library SYSRPC, we strongly recommend that you move NATCLTGS to the application library (or one of its steplibs) used by the client.
For further information on how to apply the Service Directory Maintenance function, refer to Specifying RPC Server Addresses described in Operating a Natural RPC Environment in the Natural Remote Procedure Call (RPC) documentation.
This section covers the following topics:
A service directory has a hierarchical structure with a cascading list to assign subordinate to superior fields. The highest hierarchical level is node and the lowest is program. You cannot enter node, server, library and program in the same line. If you do so, an appropriate error message appears. You need to enter the value of a subordinate field in the lines below the superior field. You can assign several servers to a node, several libraries to a server and several programs to a library.
The node and server names specified in the service directory are either physical names or logical names and logical services:
Physical node and server names denote the names of real nodes (valid TCP/IP or Entire Net-Work addresses) and servers.
In Example 1 - Standard View of Service
Directory, two servers are defined for one node. Both
servers are connected to the same node: ETB045. The remote
CALLNAT to subprogram SUB1 is executed on server
NRPC001, whereas subprograms SUB2 and
SUB3 are executed on server NRPC002.
The server names specified here must be identical to the
server names specified for the server with the profile parameter
SRVNAME
described in the Parameter Reference documentation.
Analogously, the node name in the service directory must be identical to the
node name specified for the server with the profile parameter
SRVNODE
in the Parameter Reference documentation.
Location transparency is a concept where physical node names can be replaced by logical node names, and a combination of physical node and server names can be replaced by logical services.
Logical node names and logical services are defined with EntireX and are assigned to physical node and server names at Natural runtime.
In Example 1 - Standard View of Service
Directory, *LOCTRAN in the field
Node indicates that the field Server
contains the logical service NRPC001-LOGICAL.
LOGBROKER=NODE in the field Node indicates
the logical node name.
Using Location Transparency in the section Operating a Natural RPC Environment in the Natural Remote Procedure Call (RPC) documentation.
The relevant sections in the EntireX documentation.
The Service Directory Maintenance function invokes the Natural editor. As a result, data stored in the source work area may be lost when invoking Service Directory Maintenance. An appropriate message will warn you not to delete any existing entries unintentionally: choose PF12 to cancel the function or choose ENTER to confirm the action and clear the source work area.
To invoke the Service Directory Maintenance
function
In the Code field of the Client Maintenance menu, enter the following command:
SM
If the service directory already contains service definitions, a window appears with the following message:
Existing service definitions found
In the Code field of the window, enter an
A (default) to keep old definitions and append new ones and choose
ENTER.
Or:
In the Code field of the
window, enter an I to ignore all existing definitions and delete
them from the service directory and choose ENTER.
The standard view of the Service Directory screen is displayed as shown in the following example:
15:32:25 *** NATURAL Remote Procedure Call *** 2004-04-14
Service Directory SYSRPC
Node Tr. Server Logon Library Program
1 ETB045__________ B ________________ _ ________ ________
2 ________________ _ NRPC001_________ N ________ ________
3 ________________ _ ________________ _ SYSTEM__ ________
4 ________________ _ ________________ _ ________ SUB1____
5 ________________ _ NRPC002_________ Y ________ ________
6 ________________ _ ________________ _ SYSTEM__ ________
7 ________________ _ ________________ _ ________ SUB2____
8 ________________ _ ________________ _ ________ SUB3____
9 *LOCTRAN________ _ ________________ _ ________ ________
10 ________________ B NRPC001-LOGICAL_ N ________ ________
11 ________________ _ ________________ _ SYSTEM__ ________
12 ________________ _ ________________ _ ________ SUB1____
13 LOGBROKER=NODE B ________________ N ________ ________
14 ________________ _ NRPC002_________ N ________ ________
15 ________________ _ ________________ _ SYSTEM__ ________
16 ________________ _ ________________ _ ________ S?B*____
Command ==>
Enter-PF1---PF2---PF3---PF4---PF5---PF6---PF7---PF8---PF9---PF10--PF11--PF12---
Help LocTr Exit Find -H +H -P +P Top Bot < Canc
|
The Service Directory screen provides a maximum of 500 lines for input.
If you choose PF11 or enter the less than (<) sign in the Command line, the extended node/server view of the Service Directory screen is displayed similar to the following example:
14:48:33 *** NATURAL Remote Procedure Call *** 2004-04-14
Service Directory SYSRPC
Node Tr. Server Logon
1 ETB045__________________________ B ________________________________ _
2 ________________________________ _ NRPC001_________________________ N
3 ________________________________ _ ________________________________ _
4 ________________________________ _ ________________________________ _
5 ________________________________ _ NRPC002_________________________ Y
6 ________________________________ _ ________________________________ _
7 ________________________________ _ ________________________________ _
8 ________________________________ _ ________________________________ _
9 *LOCTRAN________________________ _ ________________________________ _
10 ________________________________ B NRPC001-LOGICAL_________________ N
11 ________________________________ _ ________________________________ _
12 ________________________________ _ ________________________________ _
13 LOGBROKER=NODE__________________ B ________________________________ N
14 ________________________________ _ NRPC002_________________________ N
15 ________________________________ _ ________________________________ _
16 ________________________________ _ ________________________________ _
Command ==>
Enter-PF1---PF2---PF3---PF4---PF5---PF6---PF7---PF8---PF9---PF10--PF11--PF12---
Help LocTr Exit Find -H +H -P +P Top Bot > Canc
|
If you choose PF11 or enter the greater than (>) sign in the Command line, the standard view of the Service Directory screen is displayed as shown in Example 1 - Standard View of Service Directory.
The Service Directory screen contains the following input fields (one entry per line):
| Field | Description | ||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Node |
The name of the node to which the remote The maximum length of input is as follows:
|
||||||||||||||||||||||||
| Tr. |
The transport protocol:
|
||||||||||||||||||||||||
| Server |
The name of the server to which the remote The maximum length of input is as follows:
|
||||||||||||||||||||||||
| Logon |
|
||||||||||||||||||||||||
| Library | SYSTEM or the name of the library to which your client
application is logged on during the execution of the remote
CALLNAT.
|
||||||||||||||||||||||||
| Program |
|
||||||||||||||||||||||||
At Natural runtime, the selection of a node and server depends on the value of the fields Program and Library. Comply with the following conditions:
CALLNATThe Library field must contain the name of the current application library or SYSTEM.
The name of the subprogram specified in the CALLNAT
statement must be contained in the Program field, which
belongs to the Library field in point (1).
CALLNATThe Library field must contain the name of the current application library or SYSTEM.
All subprograms specified in the OPEN CONVERSATION
statement must be contained in a Program field, which
belongs to Library field in point (1).
The node and server used for a non-conversational or conversational
CALLNAT are taken from the superior Node and
Server fields of the Library field in
point (1).
This section contains information on the commands provided on the Service Directory screen:
The line commands provided on the Service Directory screen can be used to copy, move or delete single or multiple lines that contain field values.
Enter a line command at the beginning of a line, that is, overwrite the sequential number and choose ENTER.
See also To
copy or move a block of lines and the direct command
RESET.
| Line Command | Function |
|---|---|
A
|
Copies or moves the block of lines marked with
CC or MM below the line
in which the command was entered.
|
CC
|
Marks the block of lines to be copied. |
D
|
Deletes the marked line. |
DD
|
Marks and deletes a block of lines.
Mark a block of lines by entering this command in the first and the last line of the block and choose ENTER to execute the command. |
I
|
Inserts five empty lines below the line in which the command was entered. |
MM
|
Marks the block of lines to be moved. |
P
|
Copies or moves the block of lines marked with
CC or MM above the line
in which the command was entered.
|
To copy or move a block of
lines
At the beginning of the line where the block starts, overwrite the sequence number with either of the following line commands:
CC
to copy the block or
MM
to move the block.
At the beginning of the line where the block ends, overwrite the sequence number with either of the following line commands:
CC
to copy the block or
MM
to move the block.
Choose ENTER.
The line commands disappear, the sequence numbers are displayed again and the block of lines has been marked.
At the beginning of the line below or above which you want to place the marked block of lines, enter either of the following line commands:
A
to copy or move the block below the specified line or
P
to copy or move the block above the specified line.
Note that you can only execute A or
P on lines where at least one field is filled.
Choose ENTER.
The block of lines is copied or moved below or above the specified line.
The following direct commands and PF keys are provided on the Service Directory screen:
| Direct Command | PF Key | Function | ||||||
|---|---|---|---|---|---|---|---|---|
EXPIRATION
|
The remote directory data is loaded at runtime. The expiration
time in seconds determines the period of validity of this data. If directory
data is requested after the expiration time set, it will automatically be
reloaded. If the expiration time is set to 0, the remote directory
data will not be reloaded.
With the direct command If you do not provide a parameter with the command, the Expiration Time window appears where you can display or modify the current time. |
|||||||
RESET
|
Removes the line marks set with a line command as described in Line Commands. Note that if lines have been marked incorrectly, an appropriate
message occurs and you have to remove the erroneous line command before you
enter |
|||||||
| PF1 | Invokes the editor online help. | |||||||
| PF2 |
Invokes the Location Transparency window where you can define a logical node name or a logical service as described in Defining Logical Node Names and Logical Services. |
|||||||
| PF3 | Exit. Prompts you to save modifications and exit the Service Directory screen. | |||||||
FIND
|
PF4 |
Invokes the Find Item window where you can search for a name:
Choose ENTER to start searching and move from one hit to the next if one exists. Press PF4 to restart searching from the beginning. The hits are marked with the cursor. |
||||||
-H
|
PF5 | Scrolls half a page backward/forward. | ||||||
+H
|
PF6 | |||||||
-P
|
PF7 | Scrolls one page backward/forward. | ||||||
+P
|
PF8 | |||||||
TOP
|
PF9 | Scrolls to the beginning of the list. | ||||||
BOT
|
PF10 | Scrolls to the end of the list. | ||||||
| PF11 |
Toggles between the standard view of the Service Directory screen (see Example 1 - Standard View of Service Directory) and the extended view of the fields Node and Server (see Example 2 - Extended Node/Server View of Service Directory). |
|||||||
>
|
PF11 | Displays the extended view of the fields Node and Server. The extended node/server view does not display the fields Library and Program as shown in Example 2 - Extended Node/Server View of Service Directory. | ||||||
<
|
PF11 | Displays the standard view of the Service Directory screen as shown in Example 1 - Standard View of Service Directory. | ||||||
CANCEL
|
PF12 | Exits the Service Directory screen without saving any modifications. |
Logical node names or logical services can only be defined for node or server fields that already contain any values.
Note that defining a logical service, the original (physical) node name
will be replaced by *LOCTRAN and it is not possible to
automatically convert back logical node names or logical services. For
instructions on removing logical names and servers, see
To remove a logical node
name or logical service.
To define a logical service
Place the cursor on a Server field and choose PF2 (LocTr).
The Location Transparency - Logical Service window appears.
If desired, modify the existing values and choose ENTER.
The Server Type Conversion window appears as an additional window. Choose either of the following options:
Enter a Y (Yes) and choose ENTER to confirm
and execute the conversion.
The value in the field Node that relates to
the specified server is replaced by the following character string:
*LOCTRAN. This string indicates that a node/server combination was
converted to a logical service.
Enter any character except Y or do not enter any value
to cancel the conversion.
The physical node and server names are retained.
To define a logical node name
Place the cursor on a Node field and choose PF2 (LocTr).
The Location Transparency - Logical Node Name
window appears with the preset value of
LOGBROKER=name where
name denotes the logical EntireX Broker name.
If desired, modify name but do not modify
the character string LOGBROKER=.
Choose ENTER to confirm and execute the conversion.
The physical node name is converted to a logical name.
Or:
Choose PF12 (Canc) to cancel the conversion.
The physical node name is retained.
To remove a logical node name or
logical service
For a logical node name:
In the Node field, remove the character
string LOGBROKER=.
For a logical service:
Delete the logical service and insert physical server(s) by
using the line commands
D and I as described in
Line Commands.