Administering the RPC Server for Batch

The EntireX RPC Server for z/VSE Batch allows standard RPC clients to communicate with RPC servers on the operating system z/VSE under Batch. It supports the programming language COBOL and works together with the COBOL Wrapper and IDL Extractor for COBOL. This document covers the following topics:

Customizing the RPC Server

The name of the delivered example configuration file is RPCPARM.CFG (see sublibrary EXP960). The configuration file contains the configuration for the RPC Server for Batch. 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.

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  

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=ibm-273

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.

 
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
etblnk BKIMB Define the broker stub to be used. See Administering Broker Stubs under z/VSE for available stubs.

Example:
ETBL=BKIMB

 O
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

 O
marshalling COBOL
The RPC Server for Batch can be configured to support either COBOL or C. See also Locating and Calling the Target Server.

marshalling=(LANGUAGE=COBOL| C)
COBOL Server supports COBOL. The COBOL servers are called directly without a server interface object. So-called server mapping files are used to call the COBOL server correctly if one is available. See Usage of Server Mapping Files.
C Server 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 Batch 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 Batch stops.

Example:
restartcycles=30

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

 O
runoption no default This parameter is for special purposes. It provides the RPC Server for Batch with additional information. The runoptions are normally set to meet the platform's requirements. Set this parameter only if a support representative provides you with an option and asks you to do so. The parameter can be defined multiple times.

Example:
runoption=<option>
runoption=<option>

 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 ERXSVM 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 DLBL name ERXSVM. If this DLBL name 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 Step 3: Customize the Startup JCL - RUNRPC.J under Installing the z/VSE EntireX RPC Servers. There are also client-side mapping files that do not require configuration here; see Server Mapping Files in the EntireX Workbench in the EntireX Workbench documentation.

svm = no| dlblname

no No server-side mapping files are used.
dlblname DLBL name of the server-side mapping container in the startup JCL of the RPC Server for Batch.

Example:
svm=MYSVM

For the example above, define the DLBL name MYSVM in the startup JCL of the RPC Server for Batch as 

// DLBL MYSVM,'ENTIREX.SVMDEV.KSDS',0,VSAM,CAT=VSESPUC

See also Usage of Server Mapping Files.

O
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
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 Batch 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 Batch.
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

The IDL library and IDL program names that come from the 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 RPC Server for Batch environment. Different mechanisms are used depending on the language:

COBOL

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

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

  1. Make sure that all z/VSE modules called as RPC servers

    • are compiled with IBM's Language Environment (see LE/VSE V1R4 Programming Guide for more information)

    • use COBOL calling conventions

    • can be called dynamically ("fetched") from any Language Environment program

    • are accessible through the RPC Server for Batch JCL LIBDEF chain.

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

    marshalling=COBOL

  3. Configure the parameter svm depending on whether server-side mapping files are used or not. See Usage of Server Mapping Files.

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

C

The approaches needed to derive the names for the RPC Server for Batch are more complex for C, for the following reasons:

You need to restrict yourself to short IDL library names.

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

  • Configure the parameter marshalling for C, for example 

    marshalling=C

See Using the C Wrapper for the Server Side (z/OS, UNIX, Windows, BS2000, IBM i).

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 with EntireX in the EntireX Security documentation.

Establishing an SSL connection on z/VSE requires BSI's Automatic Transport Layer Security (ATLS). This facility is similar to z/OS Application Transparent - Transport Layer Security (AT-TLS). ATLS is supported by the BSI stack only.

Using BSI's Automatic Transport Layer Security (ATLS)

Together with SSL parameters (to provide certificates), define ATLS rules for socket interception in the ATLS daemon startup job BSTTATLS graphics/no2.gif. If the rules match, the socket connection is turned into an SSL connection graphics/no5.gif. Refer to your IBM documentation for further information. For an overview, refer to the IBM Redbook Enhanced Networking on IBM z/VSE; for a more detailed description, refer to BSI SSL Installation, Programming and User's Guide.

graphics/adminRpc_ssl_config-vse.png

graphics/no1.gif BSI TCP/IP Stack, either BSTTINET (IPv4) or BSTT6NET (IPv6).
graphics/no2.gif ATLS rules are defined manually. See Sample ATLS Daemon Configuration below.
graphics/no3.gif BSTTATLS is associated with a TCP/IP stack.
graphics/no4.gif Application using TCP connection.
graphics/no5.gif BSTTATLS intercepts outbound TCP connection and converts it to SSL connection. For inbound, SSL connections can also be intercepted and converted to TCP connections.

Start of instruction setTo set up SSL with ATLS

  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 SSL/TLS Sample Certificates Delivered with EntireX in the EntireX Security documentation.

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

    ETB024:1699:TCP

  3. Configure ATLS to turn the TCP/IP connection to an SSL connection, see above.

  4. Make sure the SSL server to which the RPC Server for Batch 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:

Starting the RPC Server

Start of instruction setTo start the RPC Server for Batch

  • Run the job RPCRPC.J.

Stopping the RPC Server

Start of instruction setTo stop the RPC Server for Batch

  • Use the following console command:

    task_id STOP

    Or:
    Use the command-line utility ETBCMD.

Activating Tracing for the RPC Server

Start of instruction setTo activate tracing for the RPC Server for Batch

  1. Set the parameter tracelevel.

  2. Temporarily change the trace level with the operator command

    port_number TRACELEVEL=tracelevel

    See the table below for supported trace levels.

    The TRACELEVEL command without tracelevel option will report the currently active trace.