To support session configuration, the connector definition uses the following attributes:
JCA LU0 Connector J2C custom property
luNames
Names of the Logical Units (LUs). The names of the Logical Units are separated by comma. If poolNameUsed is set true, the luNames should be the pool name of Communication Server.
hostApplicationName
Name of the application to be executed on the host.
poolNameUsed
Specify if the luNames property is a pool name of Communication Server. The default value is false.
automaticSessionEstablishment
If session is to be re-established after session down.The default value is true.
establishSessionRetries
The count of retries to establish session after session down. The default value is 9.
timeBetweenRetries
The delay time between the retry to establish session.The default value is 60000 ms.
fmhHeaderSent
Indicates whether the message sent to the host must include the FMH (Function Management Headers) protocol. The default value is false.
fmhIncluded
Indicates whether the connector removes the FMH (Function Management Headers) protocol. The default value is false.
establishSessionTimeout
Number of milliseconds that the connector waits before failing the attempt to create the conversation.
Compression
Indicates whether the messages are compressed. The host application and communication server are responsible for doing the compression. The default value is false.
sendInitSelf
Indicates whether INITSELF is sent to host when establishing LU-LU session. The default value is true.
sendTermSelfForTimeout
Indicates whether TERMSELF is sent to host when receiving is timeout. The default value is true.
codePageConvert
Indicates whether the code page is converted for the date sent to host and the data received from host. The default value is false.
codeSet
The code set of host used to translate code page between host and Application. The default value is Cp037.
codePage
The code Page of Application Sever used to translate code page between application and host. The default value is 8859_1.
Username
Name of a user who is authorized to create a JCA connection. Applications can call Lu0ConnectionSpec. setUserName to set it.
userPassword
Password of property username for JCA authorization.
The JCA LU0 Connector uses dynamic link libraries (DLLs) to execute CPIC native calls to the communications server.
Different DLL files are provided for different operating systems and communications servers:
▪ lu0wrap.dll for Windows version of IBM Communications Server.
▪ liblu0wrap.so.aix for AIX . Rename liblu0wrap.so.aix to liblu0wrap.so
▪ liblu0wrap.so.aix64 for 64-bit AIX. Rename liblu0wrap.so.aix64 to liblu0wrap.so
▪ liblu0wrap.so.linux for LINUX. Rename liblu0wrap.so.linux to liblu0wrap.so
After you install UDTT, these DLL files are in the <toolit_root>\lib\comms directory. Rename the appropriate DLL and install it to a directory which is accessible through environment variable. The DLLs can be used both on client side and server side of the Communication Server.
The SNA JCA LU0 Connector provides the following support for the SNA Flow Control protocols:
▪ Chaining Protocol - The connector automatically performs chaining and returns a chained message to the application if the original response message would exceed the maximum RU size. The connector also builds SNA headers from the sent information message and sends the Change Direction Indicator (CDI) along with a Last In Chain (LIC).
▪ Bracket Protocol - The connector manages the bracket protocol to inform the application of the bracket status. It also handles the CDI indicators. The connector sets the session to the between brackets state when the connector has received an End Bracket (EB) message but not yet received a new Begin Bracket (BB) message. When the session is in the between brackets state and the connector sends a chain message, the first message in the chain has the BB indicator.
▪ BID Protocol - At the session level, the connector manages the BID protocol to generate a positive response if the session is between brackets. Otherwise, the connector generates a negative response. When the session changes to the between brackets state, the connector sends a Ready To Receive (RTR) command to accept data coming from the host.
▪ Function Management Headers (FMH) Protocol - The connector removes the FMH if it received a message with an FMH and the fmhIncluded attribute was enabled. If the connector sends a message to the host with an FMH, the fmhHeaderSent attribute must be enabled.
▪ Response Protocol - The connector session handles the responses.
The SNA JCA LU0 Connector is packaged as a resource adapter module in the snalu0.rar file. This file contains the classes and the deployment descriptor containing the resource adapter configuration attributes. The file is in <toolkit_root>\lib\comms directory. You can use the RAR file to deploy the connector as a standalone unit in the application server.
Remote API Client Support for Communication Server
The UDTT JCA LU0/LU62 Connector supports the following versions of Communication Server and also supports the Remote API Client for these Communication Server:
▪ Communication Server for Windows
▪ Communication Server for AIX
▪ Communication Server for Linux
For Communication Server for Windows, the remote API client is on Windows.
For Communication Server for AIX for Linux, the remote API client is on Windows(both 32bit and 64bit), Linux and AIX.
When using the remote API Client, the Communication Server Remote API Client is installed on the WebSphere Application Server, and the Communication Server resides on a remote machine.
Mismatched transaction request and response message means that the current transaction request receives the response message of the previous transaction request. Because UDTT JCA LU0 Connector uses a queue buffer to keep the messages, the message is not removed until the application reads the message. So there can be problems if the application does not read the message for some reason.
Avoid the mismatch problem by following ways:
▪ Verify the message content to match the transaction request and response.
▪ Add a new JCA verb "SYNC_CLEAR_MSG_QUEUE" to clean the message queue. The application can call this verb before sending transaction data.