Administering the RPC Server for BS2000

The EntireX RPC Server for BS2000 allows standard RPC clients to communicate with RPC servers on the operating system BS2000. It supports the programming languages COBOL and C.

This document covers the following topics:

Customizing the RPC Server

The following elements are used for setting up the RPC Server for BS2000:

Common Runtime Environment (CRTE)

When the RPC Server for BS2000 calls COBOL or C server programs, the BS2000 Common Runtime Environment (CRTE) is loaded dynamically into the corresponding address space of the worker task.

There is no need to bind the CRTE statically to the called server object modules. If this is needed for any reason, the CRTE must be linked as a subsystem. All entries must be hidden to prevent duplicates. Linking the CRTE statically will occupy resources and slow down the load time of the server object modules.

The CRTE is not delivered with this package. For a detailed description, see the CRTE (BS2000) User's Guide.

Configuration File

The name of the delivered example configuration file is "RPC-CONFIG". The configuration file contains the configuration for the RPC Server for BS2000. The following settings are important:

  • connection information such as broker ID, server address (class, name, service)

  • location and usage of server-side mapping container, see Usage of Server Mapping Files

  • scalability parameters

  • trace settings

  • etc.

For more information see Configuring the RPC Server.

Start Procedure

The name of the start S-procedure for the RPC Server for BS2000 is "START-RPC-SERVER". The start procedure contains the following:

  • the location of the Common Runtime Environment (CRTE)

  • the target server library name of the called COBOL or C server

  • the configuration file used; see Configuration File

  • etc.

Configuring the RPC Server

The following rules apply:

  • In the configuration file:

    • Comments must be on a separate line.

    • Comment lines can begin with '*', '/' and ';'.

    • Empty lines are ignored.

    • Headings in square brackets [<topic>] are ignored.

    • Keywords are not case-sensitive.

  • Underscored letters in a parameter indicate the minimum number of letters that can be used for an abbreviated command.

    For example, in brokerid=localhost, brok is the minimum number of letters that can be used as an abbreviation, that is, the commands/parameters broker=localhost and brok=localhost are equivalents.

Parameter Default Values Req/
Opt
brokerid localhost Broker ID used by the server. See Using the Broker ID in Applications.

Example:
brokerid=myhost.com:1971

 R
class RPC Server class part of the server address used by the server. The server address must be defined as a service in the broker attribute file (see Service-specific Attributes). Case-sensitive, up to 32 characters. Corresponds to CLASS.

Example:
class=MyRPC

 R
codepage no codepage transferred

The codepage tells the broker the encoding of the data. The application must ensure the encoding of the data matches the codepage. The RPC server itself does not convert your application data. The application's data is shipped and received as given. Often, the codepage must also match the encoding used in the RPC server environment for file and terminal IO, otherwise unpredictable results may occur.

By default, no codepage is transferred to the broker. It is assumed the broker's locale string defaults match. See Locale String Mapping If they do not match, provide the codepage here. Example: 

codepage=EDF041

Enable character conversion in the broker by setting the service-specific attribute CONVERSION to "SAGTRPC". See also Configuring ICU Conversion under z/OS | UNIX | Windows | BS2000 | z/VSE. More information can be found under Internationalization with EntireX.

R
compresslevel N Enforce compression when data is transferred between broker and server. See Data Compression in EntireX Broker.

compresslevel= 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8| 9 | Y | N

0-9 0=no compression
9=max. compression
N No compression.
Y Compression level 6.

Example:
compresslevel=6

 O
deployment NO Activates the deployment service, see Deployment Service. Required to use the Server Mapping Deployment Wizard. See Server Mapping Deployment Wizard in the EntireX Workbench documentation.
YES Activates the deployment service. The RPC server registers the deployment service in the broker.
NO The deployment service is deactivated. The RPC server does not register the deployment service in the broker.

Example:
deployment=yes

 O
init_exit   Initialization exit. The RPC Server for BS2000 provides user exits that allow you to plug in code during initialization and termination of RPC worker tasks. This parameter specifies the name of an executable module that is loaded and executed during initialization of each worker task. See also term_exit.

Example:
init_exit=myExit

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extractor NO The extractor service is a prerequisite for remote extractions. See Extractor Service.

extractor=YES|NO

Example:
extractor=yes

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logon YES Execute broker functions LOGON/LOGOFF in worker threads. Must match the setting of the broker attribute AUTOLOGON. Reliable RPC requires logon set to YES. See Reliable RPC.
NO No logon/logoff functions are executed.
YES Logon/logoff functions are executed.

Example:
logon=no

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marshalling COBOL The RPC Server for BS2000 can be configured to support either COBOL or C. See also Locating and Calling the Target Server.
marshalling=(LANGUAGE=COBOL|C)
COBOL The RPC Server for BS2000 supports COBOL. The COBOL servers are called directly without a server interface object. The COBOL server modules may be compiled as OM or LLM modules. So-called server mapping files are used to call the COBOL server correctly if one is available. See Usage of Server Mapping Files.
C The RPC Server for BS2000 supports C. The modules are called using a server interface object built with the C Wrapper.
O
password no default Password for broker logon. Case-sensitive, up to 32 characters. For more information see broker ACI control block field PASSWORD.

Example:
password=MyPwd

 O
restartcycles 15 Number of restart attempts if the broker is not available. This can be used to keep the RPC Server for BS2000 running while the broker is down for a short time. A restart cycle will be repeated every 60 seconds.

When the number of specified cycles is reached and a connection to the broker is not possible, the RPC Server for BS2000 stops.

Example:
restartcycles=30

The server waits up to 30 minutes before it terminates due to a missing broker connection.

 O
servername SRV1 Server name part of the server address used by the server. The server address must be defined as a service in the broker attribute file. See Service-specific Attributes. Case-sensitive, up to 32 characters. Corresponds to SERVER of the broker attribute file.

Example:
servername=mySrv

 R
service CALLNAT Service part of the server address used by the server. The server address must be defined as a service in the broker attribute file. See Service-specific Attributes. Case-sensitive, up to 32 characters. Corresponds to SERVICE attribute of the broker attribute file.

Example:
service=MYSERVICE

 R
svm PREFERRED Usage of server mapping files. See Server-side Mapping Files in the RPC Server.

SVM=PREFERRED|NO

PREFERRED This setting is to support COBOL server programs that do not have server-side mapping, plus COBOL server programs built with a server-side mapping file. If you use server-side mapping files, the server-side mapping container must be installed and configured. See Step 1: Define a Server-side Mapping Container in the BS2000 Installation documentation. There are also client-side mapping files that do not require configuration here; see Server Mapping Files for COBOL in the EntireX Workbench documentation.
NO Server-side mapping files are not used.

Example for BS2000:
SVM=NO

See also Usage of Server Mapping Files.

O
term_exit   Termination exit. The RPC Server for BS2000 provides user exits that allow you to plug in code during initialization and termination of RPC worker tasks. This parameter specifies the name of an executable module that is loaded and executed during termination of each worker task. See also init_exit.

Example:
term_exit=myExit

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timeout 60 Timeout in seconds, used by the server to wait for broker requests. See broker ACI control block field WAIT for more information. Also influences restartcycles and worker model DYNAMIC.

Example:
timeout=300

 O
tracedestination ERXTrace.nnn.log

Trace output is written to SYSOUT. See also Activating Tracing for the RPC Server.

O
tracelevel None Trace level for the server. See also Activating Tracing for the RPC Server. 
tracelevel = None | Standard | Advanced | Support
None No trace output.
Standard For minimal trace output.
Advanced For detailed trace output.
Support This trace level is for support diagnostics and should only be switched on when requested by Software AG support.

Example:
tracelevel=standard

 O
userid ERX-SRV Used to identify the server to the broker. See broker ACI control block field USER-ID. Case-sensitive, up to 32 characters. The default ERX-SRV will be used if this parameter is omitted or specified as a null value, for example "userid=".

Example:
userid=MyUid

 O
workermodel SCALE,1,3,slowshrink
The RPC Server for BS2000 can be configured to

  • use a DYNAMIC worker model, which adjusts the number of worker threads to the current number of client requests: 

    workermodel=(SCALE,from,thru
              [,slowshrink | fastshrink])

  • use a FIXED number of worker threads: 

    workermodel=(FIXED,number)
FIXED A fixed number of worker threads is used by the RPC Server for BS2000.
SCALE The number of worker threads is adjusted to the current number of client requests. With the from value, the minimum number of active worker threads can be set. This allows you to define a certain number of threads - not used by the currently executing RPC request - to wait for new RPC client requests to process. In this way the RPC server is ready to handle many RPC client requests arriving at the same time. The thru value restricts the maximum number of all worker threads concurrently.
slowshrink Default. The RPC server stops all worker threads not used in the time specified by the timeout parameter, except for the number of workers specified as minimum value.
fastshrink The RPC server stops worker threads immediately as soon as it has finished its conversation, except for the number of workers specified as minimum value.
Example:
workermodel=(SCALE,2,5)
O

Locating and Calling the Target Server

Target server programs are loaded dynamically, using the BS2000 BLSLIB chain. The target server library name needs to be set up as PROGRAM-LIB in the parameter declaration section of the START-RPC-SERVER S-procedure, see Start Procedure. Different mechanisms are used depending on the language:

COBOL

The approach used to derive the COBOL object module name for the RPC server depends on whether server mapping is used or not. See Usage of Server Mapping Files for an introduction.

  1. If the RPC client sends a client-side type of server mapping with the RPC request, this server mapping is used first.

  2. If no server mapping is available from step 1 above, and if server-side type of server mapping is used, the IDL library and IDL program names are used to form a key to locate the server mapping in the server-side mapping container. If a server mapping is found, this is then used.

  3. If a server mapping is available from step 1 or 2 above, the COBOL object module name of the RPC server is derived from this mapping. In this case the IDL program name can be different to the COBOL object module name if it is renamed during wrapping process (see Customize Automatically Generated Server Names) or during the extraction process in the COBOL Mapping Editor.

  4. If no server mapping is used at all, the IDL program name is used as the COBOL object module name of the RPC server (the IDL library name is ignored).

See also Scenario I: Calling an Existing COBOL Server or Scenario II: Writing a New COBOL Server.

Start of instruction setTo use the RPC Server for BS2000 with COBOL

  1. Make sure that all target server programs called as RPC servers

    • are COBOL object modules

    • use COBOL calling conventions

  2. Configure the parameter marshalling for COBOL, for example: 

    marshalling=COBOL

C

Start of instruction setTo use the RPC Server for BS2000 with C

  1. Make sure that all target server programs called as RPC servers

    • are C object modules

    • use C calling conventions

  2. Configure the parameter marshalling for C, for example: 

    marshalling=C

See Scenario III: Writing a New C Server.

Starting the RPC Server

Start of instruction setTo start the RPC Server for BS2000

  • Use the following SDF command: 

    /ENTER-PROCEDURE *LIB(LIB=EXP811.JOBS,ELE=START-RPC-SERVER), -
/JOB-NAME=RPCMAIN,LOG=*NO

Stopping the RPC Server

Start of instruction setTo stop the RPC Server for BS2000 from a privileged user ID

  • Enter the command:

    /INFORM-PROGRAM MSG='STOP',JOB-IDENTIFICATION=*TSN(TSN=tsn)
    where tsn is the task number associated with the RPC Server for BS2000 main task (in the example above the TSN of RPCMAIN)

    All other tasks that were created as a result of starting the RPC Server for BS2000 will be stopped automatically.

Start of instruction setTo stop the RPC Server for BS2000 from an operator console

  • Enter the command:

    /INTR tsn,STOP
    where tsn is the task number associated with the RPC Server for BS2000 main task (in the example above the TSN of RPCMAIN)

    All other tasks that were created as a result of starting the RPC Server for BS2000 will be stopped automatically.

Start of instruction setTo stop the RPC Server for BS2000 from a non-privileged user ID

  • Use S-procedure STOP-RPC-SERVER in EXP811.JOBS.

    Startup Parameter Description Default
    BROKER-ID Depending on the communication method, the broker ID can be specified in two different formats:
    • TCP Transport Method 
      ip:port:TCP
      where ip is the address or DNS host name,
        port is the port number that EntireX Broker is listening on, and
        TCP is the protocol name
    • NET Transport Method 
      ETBnnn:SVCmmm:NET
      where nnn is the ID under which EntireX Broker is connected to the Adabas ID table,
        mmm is the SVC number under which the Adabas ID table can be accessed, and
        NET is the protocol name
    		none
    CLASS The class name under which the RPC server is registered at the EntireX Broker. RPC
    SERVER The server name under which the RPC server is registered at the EntireX Broker. SRV1
    SERVICE The service name under which the RPC server is registered at the EntireX Broker. CALLNAT
    USERID If EntireX Broker is running with EntireX Security, a user ID needs to be supplied none
    PASSWORD If EntireX Broker is running with EntireX Security, a password needs to be supplied none
    EXX-JOBS EntireX Broker jobs library EXX811.JOBS
    EXX-LIB EntireX Broker module library EXX811.LIB
    WAL-MOD WAL module library WAL826.MOD

    Set the broker ID in the PARAMETER-DECLARATION section and enter following command: 

    /CALL-PROCEDURE (EXP811.JOBS, STOP-RPC-SERVER)

Activating Tracing for the RPC Server

Start of instruction setTo switch on tracing for the RPC server

  • Set the parameter TRACELEVEL in S-element RPC-CONFIG in EXP811.JOBS.

    To evaluate the return codes, see Error Messages and Codes.