Administering the CICS RPC Server

The EntireX z/OS CICS® RPC Server allows standard RPC clients to communicate with RPC servers on the operating system z/OS under CICS. It supports the programming languages COBOL and PL/I.

This document covers the following topics:

Customizing the RPC Server

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

ERXMAIN Control Block

ERXMAIN Macro

  • creates an ERXMAIN Control Block, a persistent setup of the CICS RPC Server

  • needs to be assembled to define a setup

  • is defined in Assembler program EMAINGEN (in EXP990.SRCE) - use this for assembling; see Build the ERXMAIN Control Block under Installing EntireX RPC Servers under CICS

RPC Online Maintenance Facility

  • provides commands (see column 2 in the table below) to vary most of the permanently defined parameters in the ERXMAIN Control Block currently in use. All modifications are lost if CICS is restarted. Use ERXMAIN Macro for permanent modifications

  • allows you to try out new setups of the CICS RPC Server easily without the need to reassemble the ERXMAIN Control Block.

  • supports

    • starting

    • stopping

    • pinging

    • monitoring

    • activating trace

    of the CICS RPC Server. See RPC Online Maintenance Facility.

IBM LE Runtime Options

Depending on the feature the CICS RPC Server needs to support (see table below) additional runtime options for IBM's Language Environment need to be set. For a full description of LE runtime options, see z/OS V1R4.0 Lang Env Prog Guide.

Feature LE Runtime Options Description
Trap abends of called RPC server programs ABTERMENC(RETCODE) (1) Required to also trap the LE abends within a server program.
Level of information if called RPC server program terminates by unhandled condition TERMTHDACT(UADUMP) (1) Forces a U4039 system dump for abends not trapped by the server.
Force HANDLE ABEND LABEL getting control for COBOL runtime error and others USRHDLR=(CEEWUCHA) (1) The server traps abends using CICS HANDLE ABEND. With Enterprise COBOL for z/OS, errors resulting from the COBOL runtime (table overflow, for example) bypass the CICS abend handler. Setting CEEWUCHA enables the CICS abend handler to also trap the COBOL runtime errors.
Call RPC server programs with AMODE 24 as well ALL31(OFF),STACK(,,BELOW) If not specified, AMODE 31 is supported.

Note:
(1) Set internally by the CICS RPC Server using application-specific CSECT CEEUOPT. The options can be changed if CEEUOPT is replaced on CICS RPC Server load module RPCSRVC with IBM Linkage Editor.

There are various ways of specifying LE runtime options, for example installation-specific, region-specific (CEEROPT available in the DFHRPL concatenation) or application-specific (linked CSECT CEEUOPT) etc.

CICS Settings

CICS Parameter Description Default How to change?
TWASIZE Transaction Work Area (TWA) size may be used by target RPC programs called by the CICS RPC server. If this is the case, the TWA size set for the CICS RPC server must match the largest TWA size required by all called target RPC programs. TWASIZE(28)

This corresponds to 'Adabas Parameter List' if transport method NET is used. See Installing Adabas with TP Monitors for EntireX.

  • Use resource definition online (RDO), CICS transaction CEDA.

  • See member DFHERX in EXP990.SRCE data set. See Update the CICS Tables.

Configuring the RPC Server

The following rules apply for the ERXMAIN Macro syntax (column 1 in table below):

  • keywords are given in uppercase

  • there are no abbreviations for keywords

The following rules apply for the RPC Online Maintenance Facility commands (column 2 in table below):

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

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

ERXMAIN Macro Syntax RPC Online Maintenance Facility Commands Default Values Req/
Opt
BKRN brokerid ETB001 Broker ID used by the server. See Using the Broker ID in Applications.

Example:
BKRN=myhost.com:1971

 R
CLZN 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 under Broker Attributes). Case-sensitive, up to 32 characters. Corresponds to CLASS attribute of the broker attribute file.

Example:
CLZN=MyRPC

R
SRVN 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 under Broker Attributes. Case-sensitive, up to 32 characters. Corresponds to SERVER of the broker attribute file.

Example:
SRVN=mySrv

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SVCN 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 under Broker Attributes. Case-sensitive, up to 32 characters. Corresponds to SERVICE attribute of the broker attribute file.

Example:
SVCN=MYSERVICE

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CODE codepage no codepage transferred Depending on the internationalization approach, the codepage (locale string) where incoming data is provided to the COBOL server. Conversely, the COBOL server must provide outgoing data in the given codepage, otherwise unpredictable results occur. See What is the Best Internationalization Approach to use? under Internationalization with EntireX for information on which internationalization approach requires a codepage (locale string).

By default, no codepage is transferred to the broker. For the most popular internationalization approach, ICU Conversion, the correct codepage (locale string) must be provided. This means it must:

  • follow the rules described under Locale String Mapping

  • be a codepage supported by the broker

  • be the codepage used in your environment for file and terminal IO, otherwise unpredictable results may occur.

Example:
CODE=ibm-273

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COMP 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:
COMP=6

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

When the number of cycles is reached and a connection to the broker is not possible, the RPC server stops.

Example:
CYCL=30

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DPLY 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:
DPLY=YES

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ENCR encryptionlevel 0 Deprecated. For encrypted transport we strongly recommend using the Secure Sockets Layer/Transport Layer Security protocol. See SSL/TLS and Certificates with EntireX. O
ENDW endworker TIMEOUT
NEVER Defines worker model FIXED with a fixed number of worker threads. The number of active workers is defined with ERXMAIN macro parameter MINW.
TIMEOUT Defines slow-shrinking worker model SCALE, where the number of worker threads is adjusted to the current number of client requests. With value TIMEOUT, all worker threads not used are stopped in the time specified by the ERXMAIN macro parameter TOUT, except for the minimum number of active workers specified with ERXMAIN macro parameter MINW. The upper limit of workers parallel active is restricted with ERXMAIN macro parameter MAXW.
IMMEDIATE Defines fast-shrinking worker model SCALE, where the number of worker threads is adjusted to the current number of client requests. With value IMMEDIATE, worker threads not used are stopped immediately as soon as they have finished their conversation, except for the minimum number of active workers defined with ERXMAIN macro parameter MINW. The upper limit of workers active in parallel is restricted with ERXMAIN macro parameter MAXW.

This parameter is forced to value TIMEOUT if impersonation is switched on, see Impersonation and ERXMAIN macro parameter IMPS.

Example:
ENDW=IMMEDIATE,MINW=2,MAXW=6

 O
MINW minworker 1 Minimum limit of tasks active in parallel.

  • For worker model SCALE: minimum number of workers active in parallel. Do not set a value higher than ERXMAIN macro parameter MAXW.

  • For worker model FIXED: number of workers active in parallel. Do not set a value higher than 31 without adjusting ERXMAIN macro parameter SIZE.

See also ERXMAIN macro parameter ENDW.

Example:
MINW=2

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MAXW maxworker 10 Upper limit of tasks active in parallel.

Example:
MAXW=2

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ETBL etblnk CICSETB Define the broker stub to be used. See Administering Broker Stubs for available stubs.

Example:
ETBL=CICSETB

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EXIT n.a.   At startup, the CICS RPC Server will call the user exit to synchronize its version. If successful, the CICS RPC Server will continue and call the user exit for the implemented events. See User Exit COBUEX02. O
IMPS impersonation NO
Defines if RPC requests are executed under the user ID of the RPC client. Depending on settings, different levels of checks are done prior to RPC server execution. See also Impersonation.

impersonation= NO | YES | AUTO [, sameuser | , anyuser ]
 

NO The RPC request is executed anonymously, which means the user ID of the RPC client is not used. RPC requests are executed under the user ID of the RPC server.
YES The RPC request runs impersonated under the supplied RPC client user ID. For execution of the RPC request, the CICS RPC Server starts a separate impersonated user task, that is, the client must be know to CICS and the supplied password is validated against CICS. The worker model SCALE is forced; for details see Impersonation.
AUTO

Same as option YES above, except that no password validation is performed, that is, the client is treated as already authenticated. For this setting, make sure the RPC client is correctly authenticated; use either

  • a secure broker (validation must be against the correct mainframe security repository where the user IDs are defined) and option sameuser
    or

  • your own security implementation (option anyuser is supported for compatibility reasons if you need different broker and server user IDs - the customer-written security implementation must validate the RPC client using the RPC client user ID)

sameuser The CICS RPC Server checks whether the broker client user ID matches the RPC client user ID. This is the default if AUTO is used.
anyuser The RPC client user ID is used for impersonation. The broker client user ID is ignored.

Notes:

  1. EntireX supports two user ID/password pairs: a broker client user ID/password pair and an (optional) RPC user ID/password pair sent from RPC clients to the RPC server.
  2. With EntireX Security, the broker client user ID/password pair is checked. The RPC user ID/password pair is designed to be checked by the target RPC server. Thus it is possible to use different user IDs in the broker and target RPC server.
  3. RPC clients send the (optional) RPC user ID/password pair in the same way as specifying the Natural user ID/password pair for a Natural RPC Server. See for example Using Natural Security for applications under C | COBOL | PL/I | Web Services | SOAP/XML | Java.
  4. If the RPC client does not specify the optional RPC user ID/password pair, the broker client user ID is inherited to the RPC user ID and thus used for impersonation by the CICS RPC Server.

Example:
IMPS=auto
O
LOGN 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:
LOGN=no

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n.a. mapname   Alias for command memory. O
n.a. memory   Command to load an ERXMAIN Control Block. See Modifying Parameters of the RPC Server. O
OPTS runoption 0 This parameter is for special purposes. It provides the CICS RPC Server with additional information. The runoptions are normally set to meet the platform's requirements. Set this parameter only if a support representive provides you with an option and asks you to do so.

Syntax:
OPTS=(<option-list>)
<option-list> = [<option-list>,] <option>

Example:
OPTS=(RUNOPT1,RUNOPT2)

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PSWD password   Password for broker logon. Case-sensitive, up to 32 characters. For more information see broker ACI control block field PASSWORD.

Example:
PSWD=MyPwd

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PRELOAD preload YES Enable to call CICS RPC Server with AMODE=24
YES Enable to call RPC server with AMODE 24 or 31. Internally the CICS RPC Server preloads the called RPC server before execution to check the AMODE and releases the RPC server after this. The disadvantage of this approach is the CICS USECOUNT of the called RPC server program is increased by 2 for every executed RPC call.
NO The CICS RPC Server does not preload the called RPC server to check its AMODE. All RPC servers are called as running in AMODE 31. This option is useful for customers who require the CICS USECOUNT in their accounting (increased by 1 for every executed RPC call) but prevents usage of calling RPC Server with AMODE 24.
O
REPL replicatename ESRV CICS transaction ID (uppercase, up to 4 characters) assigned to worker tasks and as default for user tasks if Impersonation is set. In the START-USER event of the user exit (see User Exit COBUEX02) the CICS transaction ID for user tasks can be overridden. See also Introduction to the CICS RPC Server. O
SIZE n/a 32768 Upper limit of tasks active in parallel.

Example:
MAXW=2

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SMH smhport 0 The port where the server listens for commands from the System Management Hub (SMH). If this port is 0 (default), no port is used and management by the SMH is disabled.

See SMH Listener Service for more information.

Example:
SMH=3001

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SVM svmfile   Usage and location of server-side mapping files. See Server-side Mapping Files in the RPC Server. If no SVM parameter is given, the RPC server tries to open the server-side mapping container, using CICS file with name ERXSVM. If this CICS file is not available, no server-side mapping files are used. If you use server-side mapping files, the server-side mapping container must be installed and configured; see Install the Server-side Mapping Container for a CICS RPC Server (Optional) under Installing the EntireX RPC Servers under z/OS. There are also client-side mapping files that do not require configuration here; see Server Mapping Files for COBOL.

Syntax:
SVM=NO | cicsname

cicsname The RPC server tries to open the server-side mapping container using the CICS file with name cicsname.
no No server-side mapping files are used.

Example:
SVM=MYSVM

See also Usage of Server Mapping Files.

O
TOUT timeout 600 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.

See worker model SCALE to define the lifetime of worker threads in slow-shrinking worker model SCALE.

Example:
TOUT=300

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TRC1 tracedestination CSSL Name of the destination for trace output. A valid CICS transient data queue. O
TRLV tracelevel 0 Trace level for the server. See also Activating Tracing for the RPC Server.

Syntax:
TRLV= 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:
TRLV=standard

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TROP traceoption none Additional trace option if trace is active.
None No additional trace options.
STUBLOG If tracelevel is Advanced or Support, the trace additionally activates the broker stub log.
NOTRUNC Normally if a data buffer larger than 8 KB is traced, the buffer trace is truncated. Set this option to write the full amount of data without truncation.

Note:
This can increase the amount of trace output data dramatically if you transfer large data buffers.

Example:
TROP=(STUBLOG,NOTRUNC)

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USER userid ERXSRV1 Used to identify the server to the broker. See broker ACI control block field USER-ID. Case-sensitive, up to 32 characters.

Example:
USER=MyUid

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Locating and Calling the Target Server

The IDL library and IDL program names that come from RPC client are used to locate the RPC server. See library-definition and program-definition. This two-level concept (library and program) has to be mapped to the CICS RPC Server environment. Different mechanisms are used depending on the language:

COBOL

The approach used to derive the CICS program 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 CICS program name of the RPC server is derived from this mapping. In this case the IDL program name can be different to the CICS program 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 CICS program name of the RPC server (the IDL library name is ignored).

Start of instruction setTo use the CICS RPC Server with COBOL

  1. Make sure that all CICS programs called as RPC servers

    • use an interface type supported by the CICS RPC Server for target language COBOL; see Supported Interface Types.

    • can be called with an EXEC CICS LINK PROGRAM

    • are accessible through the CICS RPL chain or accessible remotely using CICS DPL

  2. Configure the ERXMAIN macro parameter SVM depending on whether server-side mapping files are used or not. See also Usage of Server Mapping Files.

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

PL/I

There is a simple mechanism to derive the RPC server CICS program name:

  • The IDL program name is used as the CICS program name.

  • The IDL library name is not used.

Start of instruction setTo use the CICS RPC Server with PL/I

  1. Make sure that all CICS programs called as RPC servers

    • use an interface type supported by the CICS RPC Server for target language PL/I; see Supported Interface Types.

    • can be called with an EXEC CICS LINK PROGRAM

    • are accessible through the CICS RPL chain or accessible remotely using CICS DPL

See also Scenario III: Calling an Existing PL/I Server or Scenario IV: Writing a New PL/I Server.

Using SSL/TLS with the RPC Server

RPC servers can use Secure Sockets Layer/Transport Layer Security (SSL/TLS) as the transport medium. The term "SSL" in this section refers to both SSL and TLS. RPC-based servers are always SSL clients. The SSL server can be either the EntireX Broker, Broker SSL Agent, or Direct RPC in webMethods Integration Server (IS inbound). For an introduction see SSL/TLS and Certificates in the Security documentation.

SSL delivered on a z/OS mainframe will typically use the Resource Access Control Facility (RACF) as the certificate authority (CA). Certificates managed by RACF can only be accessed through the RACF keyring container. A keyring is a collection of certificates that identify a networking trust relationship (also called a trust policy). In an SSL client/server network environment, entities identify themselves using digital certificates called through a keyring. Server applications on z/OS that wish to establish network connections to other entities can use keyrings and their certificate contents to determine the trustworthiness of the client or peer entity. Note that certificates can belong to more than one keyring, and you can assign different users to the same keyring. Because of the way RACF internally references certificates, they must be uniquely identifiable by owner and label, and also unique by serial number plus data set name (DSN).

With the CICS RPC Server you can use IBM's Application Transparent Transport Layer Security (AT-TLS), where the establishment of the SSL connection is pushed down the stack into the TCP layer.

Using IBM's Application Transparent Transport Layer Security (AT-TLS)

Configure the AT-TLS rules for the policy agent (PAGENT) graphics/no4.gif using an appropriate client graphics/no1.gif and the z/OS Management Facility (z/OSMF) graphics/no2.gif. Together with SSL parameters (to provide certificates stored in z/OS as RACF keyrings) define AT-TLS rules, for example by using the application graphics/no5.gif job name and remote TCP port number. If the rules match, the TCP connection is turned into an SSL connection graphics/no6.gif. Refer to your IBM documentation for more information, for example the IBM Redbook Communications Server for z/OS VxRy TCP/IP Implementation Volume 4: Security and Policy-Based Networking.

graphics/adminRpc_ssl_config-cics.png

graphics/no1.gif Client to interact with z/OS Management Facility (z/OSMF).
graphics/no2.gif AT-TLS rules are defined with z/OSMF policy management.
graphics/no3.gif Policy Repository with AT-TLS rules stored as z/OS files.
graphics/no4.gif Policy Agent, MVS task PAGENT, provides AT-TLS rules through a policy enforcement point (PEP) to TCP/IP stack.
graphics/no5.gif Application using TCP connection.
graphics/no6.gif If AT-TLS rules match, the TCP connection is turned into an SSL connection.

Notes:

  1. The client graphics/no1.gif may vary per operating system, for example a Web browser for z/OS 2.1.
  2. z/OSMF graphics/no2.gif includes other administration and management tasks in addition to policy management.
  3. Policy Management graphics/no3.gif includes other rules, such as IP filtering, network address translation etc.

Start of instruction setTo set up SSL with AT-TLS

  1. To operate with SSL, certificates need to be provided and maintained. Depending on the platform, Software AG provides default certificates, but we strongly recommend that you create your own. See Default Certificates Delivered with EntireX under SSL/TLS and Certificates with EntireX in the Security documentation.

  2. Set up the CICS RPC Server for a TCP/IP connection. On mainframe platforms, use Transport-method-style Broker ID. Example: 

    ETB024:1699:TCP

  3. Configure AT-TLS to turn the TCP/IP connection to an SSL connection, see above.

  4. Make sure the SSL server to which the CICS RPC Server connects is prepared for SSL connections as well. The SSL server can be EntireX Broker, Broker SSL Agent, or Direct RPC in webMethods Integration Server (IS inbound). See:

User Exit COBUEX02

The CICS RPC Server provides a user exit COBUEX02 to influence/control the RPC logic. This section covers the following topics:

User Exit Events

The user exit is called on the following events:

graphics/intro_userExits-cics.png

The numbers in the graphic correspond to the event numbers in the user exit.

Step Event Called Description Note
graphics/no1.gif WHICH-VERSION During startup of RPC server. The CICS RPC Server and the exit decide on the version to use. See field VERSION.  
graphics/no3.gif START-WORKER Before starting a worker task. This allows you to set the CICS transaction ID of the worker task. See field CICS-TRANSID. 1
graphics/no5.gif START-USER Before starting a user task. Requires Impersonation. Before an impersonated CICS transaction (user task) is started, the user exit may change the user ID, CICS transaction ID and CICS terminal ID of the new impersonated user task. See fields USERID, CICS-TRANSID and CICS-TERMID. 1
graphics/no7.gif CALL-START Before calling the target CICS program. See field RPC-SERVER. You can inspect and modify the RPC request (payload data from the RPC client to the RPC server). 1
graphics/no8.gif CALL-END After calling the target CICS program. See field RPC-SERVER. You can inspect and modify the RPC reply (payload data from the RPC server to the RPC client). 2

Notes:

  1. An RPC request can be terminated if an error is given in the fields ERROR-CODE and ERROR-TEXT. The RPC request is already executed.
  2. If an error is given in the fields ERROR-CODE and ERROR-TEXT, this error is returned to the RPC client. The RPC request is already executed.

Writing the User Exit

The Developer's Kit provides the following resources for COBOL:

  • User exit skeleton COBUEX02 in data set EXP990.SRCE. Copy this skeleton so you have your own user exit source for modifications. The user exit program must comply with the EXEC CICS LINK PROGRAM COMMAREA conventions.

  • Copybook COBUEX02 in data set EXP990.INCL. Please add EXP990.INCL to your COBOL compiler SYSLIB DD chain. The copybook also contains further description and usage comments.

The parameters of COBUEX02 are described below.

Parameter Format I/O Description
EXIT-FUNCTION PIC 9(4) BINARY I Signals the event. See User Exit Events.
VERSION PIC 9(4) BINARY I/O For event WHICH-VERSION, see User Exit Events. On input, the CICS RPC Server provides the maximum supported version; on output, the exit returns the version to be used. Values 1-2 may be supplied. Some of the fields require a minimum version.
TRACE-LEVEL PIC 9(4) BINARY I Informational. Value is 0-n. Corresponds to parameter tracelevel.
ERROR-CODE PIC 9(4) BINARY O Must be set on output. Possible values:
0 Success. Continue this RPC request.
1..9999 Stop the RPC request. Reply with error class 1022 together with field ERROR-TEXT to the calling RPC client.
  Example: Error code value nnnn results in the following error message: 1022nnnn error-text.
See Message Class 1022 - CICS RPC Server User Exit Messages.
ERROR-TEXT PIC X(256) O Error text returned to RPC client if an error is supplied in field ERROR-CODE. Up to 256 characters.
CICS-TRANSID PIC X(4) I/O Input defined by macro EMAINGEN. Default is ESRV. Can be modified on output. Available for the following events:
START-WORKER Transaction ID to start the WORKER-TASK.
START-USER Transaction ID to start the USER-TASK. Requires Impersonation.
CICS-TERMID PIC X(4) O Available for the following event:
START-USER If applied on output, starts the USER-TASK with the supplied terminal ID. Requires Impersonation.
USERID PIC X(32) I/O Input supplied by RPC client. Available for the following event:
START-USER If applied on output, starts the USER-TASK with the supplied user ID. Requires Impersonation.
RPC-LIBRARY PIC X(128) I IDL library name. Informational. Availability depends on event and VERSION:
START-USER If field VERSION >=2 has been set on WHICH-VERSION.
CALL-START All supported field VERSIONs.
CALL-END All supported field VERSIONs.
RPC-PROGRAM PIC X(128) I IDL program name. Informational. Availability depends on event and VERSION:
START-USER If field VERSION >=2 has been set on WHICH-VERSION.
CALL-START All supported field VERSIONs.
CALL-END All supported field VERSIONs.
INTERFACE-TYPE PIC X I Type of interface. Informational. Available for events CALL-START and CALL-END. Possible values:
D DFHCOMMAREA
C Channel Container
W Large Buffer
RPC-SERVER PIC X(8) I Target CICS program to call. Informational. Available for the following events:
CALL-START All supported field VERSIONs.
CALL-END All supported field VERSIONs.
CHANNEL-NAME PIC X(16) I Name of CICS Channel. Informational. Applicable if field INTERFACE-TYPE is 'C' (Channel Container). Available for the following events:
CALL-START All supported field VERSIONs.
CALL-END All supported field VERSIONs.
CHAIN-COUNTER PIC S9(9) BINARY I Number of DATA-ENTRY elements describing payload data. Informational. Content depends on event and interface type:
Event Interface Type Chain Counter
CALL-START DFHCOMMAREA 1
CALL-END DFHCOMMAREA 1
CALL-START Channel Container number-input-containers
CALL-END Channel Container number-output-containers
CALL-START Large Buffer 1
CALL-END Large Buffer 1
CHAIN-POINTER POINTER I Informational. Pointer to first element of a table (or chain of elements) describing payload data. See structure DATA-ENTRY. Available for the following events:
CALL-START The table or chain of elements (structure DATA-ENTRY) contains descriptions of input payload data.
CALL-END The table or chain of elements (structure DATA-ENTRY) contains descriptions of output payload data.
CHAIN-COUNTER-OUT PIC S9(9) BINARY I Similar to CHAIN-COUNTER. Number of DATA-ENTRY elements describing payload data. Informational. Content depends on event and interface type:
Event Interface Type Chain Counter
CALL-START DFHCOMMAREA 1
CALL-START Channel Container number-output-containers
CALL-START Large Buffer 1
CHAIN-POINTER-OUT POINTER I Similar to CHAIN-POINTER. Informational. See structure DATA-ENTRY. Available for the following event:
CALL-START If field VERSION >=2 has been set on WHICH-VERSION. The table or chain of elements (structure DATA-ENTRY) contains descriptions of expected output payload data with maximum length for variable length data, for example OCCURS DEPENDING ON ...
RPC-RETCODE PIC 9(9) BINARY I RPC error code. Informational.
1001 0045 CICS abend code.
1002 nnnn User-definable server message.
...  

See Error Messages and Codes.

CICS-ABCODE PIC X(4) I CICS abend code. Informational.
DATA-ENTRY   I Structure. Informational. Consists of: DATA-NAME, DATA-LENGTH, DATA-POINTER.
    DATA-NAME PIC X(16) I Name of element. Content depends on INTERFACE-TYPE. The main purpose is to deliver the container names for the interface type Channel Container.
Event Interface Type Container Name
CALL-START DFHCOMMAREA 'DFHCOMMAREA'
CALL-END DFHCOMMAREA 'DFHCOMMAREA'
CALL-START Channel Container input-container-name or output-container-name
CALL-END Channel Container output-container-name
CALL-START Large Buffer 'WM-LCB-INPUT'
CALL-END Large Buffer 'WM-LCB-OUTPUT'
    DATA-LENGTH PIC 9(9) BINARY I Length or maximum expected length:
With event CALL-START and CHAIN-POINTER-OUT: the maximum length of payload data.
For all other cases, the actual length of the payload data.
    DATA-POINTER POINTER I Pointer to payload for this element.

Configuring the User Exit

Apply the name of your exit routine to the EntireX RPC server ERXMAIN macro parameter EXIT. See Configuring the RPC Server.

At startup, the CICS RPC Server will call the named user exit to synchronize its version. If successful, the RPC Online Maintenance Facility will display the user exit as map field "parameter opts". See To display the Server parameters (PF06) under RPC Online Maintenance Facility. The CICS RPC Server will continue and call the user exit for the implemented events.

Autostart/Stop during CICS Start/Shutdown

The CICS RPC Server can be started and stopped automatically during start and stop of the CICS region. For manual start/stop, see Starting the RPC Server and Stopping the RPC Server under RPC Online Maintenance Facility.

Start of instruction setTo start the CICS RPC Server during the initialization of CICS

  1. If the COBOL source ERXSTART of the EntireX installation library EXP990.SRCE has not been defined in the CICS CSD data sets by the installation job $INSTALL, define it.

  2. Customize and compile ERXSTART if necessary.

  3. Add the following entry to your CICS PLTPI table (second phase PLT program): 

    DFHPLT TYPE=ENTRY,PROGRAM=ERXSTART

    See also Starting the EntireX RPC Server Automatically on CICS Startup (Optional) under Installing EntireX RPC Servers under CICS in the z/OS installation documentation.

Start of instruction setTo stop the CICS RPC Server during the shutdown of CICS

  1. If the COBOL source ERXSTOP of the EntireX installation library EXP990.SRCE has not been defined in the CICS CSD data sets by the installation job $INSTALL, define it.

  2. Customize and compile ERXSTOP if necessary.

  3. Add the following entry to your CICS PLTSD table (first phase PLT program): 

    DFHPLT TYPE=ENTRY,PROGRAM=ERXSTOP

    See also Stopping the EntireX RPC Server Automatically on CICS Shutdown (Optional) under Installing EntireX RPC Servers under CICS in the z/OS installation documentation.

Multiple RPC Servers in the same CICS

If you need to install multiple instances in the same CICS region, see Installing Multiple EntireX RPC Servers in the same CICS (Optional) under Installing EntireX RPC Servers under CICS in the z/OS installation documentation.