The SYSRPC utility provides functions 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 and the XML-formatted SERVDIRX file (Natural text object) in the
library that is defined with the profile parameter
RPCSDIR
(see the Parameter Reference documentation). If
RPCSDIR is set, the service directory maintenance
functions reference 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 a service
directory maintenance function.
The name of the library referenced for service directory
maintenance is indicated in the root node of the service directory tree view
(see Tree
Nodes). If RPCSDIR is set, the root
node contains Central, which indicates that the library
displayed in the window is not the library where you are currently
logged on, but the central library specified with
RPCSDIR.
For further information on how to apply the service directory maintenance functions, refer to Specifying RPC Server Addresses described in Operating a Natural RPC Environment in the Natural Remote Procedure Call (RPC) documentation.
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.
This section covers the following topics:
The main items of a service directory are node, server, library and service (subprogram). The hierarchical structure of these items is displayed as a tree view in the SYSRPC - Remote Procedure Call window (see also Service Directory Tree in Basic SYSRPC Functionality). The highest level (root node) of the tree view is Service Directory and the lowest is service (subprogram).
The node and server names specified in the service directory are either physical names or logical names and logical services.
This section covers the following topics:
Physical node and server names denote the names of real nodes (valid TCP/IP or Entire Net-Work addresses) and servers.
In the Example
of a Service Directory below, 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
described 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.
See also Example of a Service Directory and Using Logical Services and Logical Node Names.
Using Location Transparency in Operating a Natural RPC Environment in the Natural Remote Procedure Call (RPC) documentation.
The relevant sections in the EntireX documentation.
In the example of a service directory above, the icon
indicates that NRPC001-LOGICAL is a logical service.
LOGBROKER=NODE indicates that NODE is the logical
node name.
This section describes the tree nodes contained in the service directory tree view. Each tree node is identified by a different icon.
You can manipulate the tree nodes by using the functions provided by the menu bar, the toolbar and the context menu described in Basic SYSRPC Functionality.
| Icon | Tree Node | Explanation | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
|
|
Service |
The service directory root node indicates the name of the library from which the service directory was read: Service Directory [library-name]. For example: If you invoked the SYSRPC utility from the library USERLIB, the root reads Service Directory [USERLIB]. If the profile parameter For explanations of other root node names that can occur, see Root Node Names in Error Situations. |
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|
|
Node |
The name of the node to which the remote Maximum name length:
Depending on the setting of the Logon Option, either of the following icons is displayed:
See also Logon Option below. |
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|
|
Server |
The name of the server on which the Maximum name length: 32 characters Depending on the setting of the Logon Option, either of the following icons is displayed:
See also Logon Option below. |
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|
|
Logical Service |
The name of a logical service. Maximum name length: 192 characters Depending on the setting of the Logon Option, either of the following icons is displayed:
See also Logon Option below. |
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|
Library | SYSTEM or the name of the library to which your client
application is logged on during the execution of the remote
CALLNAT.
|
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|
|
Service |
The name of the remote subprogram to be accessed from the client. Maximum number of entries: 500 subprograms. |
The section below contains information on:
This section lists root node names that can occur if subprograms or text objects required by the service directory are missing, explains possible reasons and provides resolution advice.
| Node Name | Reason | Resolution |
|---|---|---|
|
Service Directory |
The text object SERVDIRX is missing. |
From the Object menu, choose Save As or Save. SERVDIRX is generated into the library for which SYSRPC was invoked and the name of the root node changes to Service Directory [library-name]. |
|
Example Service |
The subprogram NATCLTGS and the text object SERVDIRX are missing. |
From the Object menu, choose Save As or Save. NATCLTGS and SERVDIRX are generated into the library for which SYSRPC was invoked and the name of the root node changes to Service Directory [library-name]. |
| Empty tree |
NATCLTGS, SERVDIRX and the subprogram DEF-GS (delivered in the Natural system library SYSRPC) are missing. DEF-GS contains example data. |
|
At Natural runtime, the selection of a node and a server depends on the value of the service (subprogram) and library tree nodes. Comply with the following conditions:
CALLNATThe library tree node must contain the name of the current application library or SYSTEM.
The subprogram referenced in the CALLNAT statement must
be contained in the service (subprogram) tree node, which belongs to the
library tree node in point (1).
CALLNATThe library tree node must contain the name of the current application library or SYSTEM.
All subprograms specified in the OPEN CONVERSATION
statement must be contained in a service (subprogram) tree node, which belongs
to the library tree node in point (1).
The node and server used for a non-conversational or conversational
CALLNAT are taken from the superior node and server tree nodes of
the library tree node in point (1).
You can define logical services and logical node names. For an example of logical services and logical node names, see Example of a Service Directory.
To define a logical service
Select the Service Directory root node, open the Edit menu and choose New Item and Logical Service (EntireX).
Or:
Select the Service Directory root node and
choose New Item and Logical Service
(EntireX) from the context menu.
To define a logical node name
Select the tree node for the required node, choose Rename from the context menu or press F2, and replace the existing value by the following:
LOGBROKER=node-name
where node-name denotes the logical EntireX Broker name.
To remove a logical node name
Select the tree node for the required node, choose
Rename from the context menu or press F2, and
replace the string LOGBROKER= by an EntireX Broker name.
To display physical names defined for logical services or nodes
Use the ping command as described in the section Server Command Execution.
Ping invokes a window that displays the physical node and server names defined for a logical service or a physical node name defined for a logical node.
If the Logon Option is set, for each
CALLNAT request, the client initiates a Natural logon to the
server using the current library name on the client, regardless of the library
specified in the service directory. You can use the Application Programming
Interface USR4008N to specify a different library; see also Logging on
to a Different Library in
Using the Logon
Option in the Natural Remote Procedure Call
(RPC) documentation.
After the remote CALLNAT has been executed (successfully or
not), the server library is reset to its previous state. For more information,
see Using the Logon
Option in the Natural Remote Procedure Call
(RPC) documentation.
The Logon Option can be set at server or node level and applies to all definitions made at a hierarchically lower level. If the Logon Option has been set for a certain server, it applies to all associated library and subprogram definitions.
To set the Logon Option
In the Service Directory tree view, select the tree node of a node, a server or a logical service and choose Logon Option from the context menu.
Choose Yes to set the Logon Option for the server. (The default is No.)
If the Logon Option has been set successfully
for the node selected, the icon indicating a node changes from
to
.
If the Logon Option has been set successfully
for a logical service, the icon indicating a logical service changes from
to
.
If the Logon Option has been set successfully
for the server selected, the icon indicating a server changes from
to
.
To specify the transport protocol
In the Service Directory tree view, select the tree node of a node, a server or a logical service and choose Transport Protocol and ACI for EntireX Broker ACI protocol from the context menu.