Question & Answer
Question
What logs could be collected when you experience issues with the Remote Connection Emulator (RCE) in IBM Developer for z/OS (IDz)?
Cause
The most common problem is failure to connect to the host when the Remote Connection Emulator uses encrypted communication configuration like TLS.
Answer
| When using | Traces to collect |
|---|---|
|
IDz Eclipse client
|
|
|
IDz in VS code
Z Open Editor
|
|
Possible causes and solutions
See the link section for the z/OS documentation of these errors.
Some possible causes for errors that can be found on the z/OS SYSLOG:
| Error | Possible cause | Resolution |
|---|---|---|
|
The error can indicate that the client side broke the connection. For example if the server certificate is not trusted by the client and the client side is configured to check it
|
Add the server certificate to the client key store. On Windows (a)
|
|
The host closed the connection because no client certificate was provided
|
Select a client certificate on the RCE connection properties
 |
 |
When launched from Z Open Editor, the host TN3270 closed the connection because it requires a client certificate but RSEAPI doesn't support it
|
In rseapi.env, configure a TN3270 port that do not require a client certificate
|
|
The host closed the connection because the client certificate was not recognized
|
|
|
The client certificate alias was not found the keystore
|
On Windows, verify in certmgr that your client certificate alias is listed under Personal > Certificate in column Friendly Name
|
|
CommonPropertiesRESTService EXCEPTION : Exception in GET - Get a list of all Common Properties Namespaces with userid USERXYZ
com.ibm.rse.rest.exception.RestWAFunctionDisabledException: Common Properties service is not enabled. |
Error is printed to the RSEAPI STC joblog if common properties is not enabled in rse.env.
The error can be ignored and should not prevent a successful connection with RCE
|
Set variable RSE_COMMON_PROPERTIES in rseapi.env
|
|
Menu "Launch 3270 emulator in Web browser" is not available in Zower Explorer
 |
|
|
a) Verify your certificates in the Microsoft Windows-MY keystore
From a command line, enter command
certmgr /s my
- Host certificate has to be trusted
Verify that your host CA certificate is trusted (installed under Trusted Root)
- When using Client certificate
If your host requires a client certificate, then import it into Windows-MY under Personal > Certificates
Select it on the Remote Connection Emulator
1) Enable tracing in IDz Eclipse client
- Enable tracing with menu Window > Preferences > Tracing and set com.ibm.remote.connection.emulator to FINEST
Output is printed to
<your workspace>\.metadata\.trace
2) Test connection in RCE
Perform a test connection on the Remote Connection Emulator
3) Enable AT-TLS traces on z/OS
When using AT-TLS, add a trace statement to the TTLSConnectionAction of your policy file, like for example:
TTLSConnectionAction TN3270_conn
{
HandshakeRole Server
TTLSCipherParmsRef TN3270_cipherparms
TTLSConnectionAdvancedParmsRef TN3270_Conn_adv
CtraceClearText Off
Trace 255
}
Traces are printed to the z/OS system console, like for example:
(4) To collect the output view log of the "Z Open Editor" extension in Visual Studio Code
- Enable DEBUG level from menu File > Preferences > Settings > Extension > IBM Z Open Editor and set Logger=DEBUG
- Reproduce the problem;
- Open the output view from menu View > Output and send the content for "IBM Z Open Editor"
5) RSEAPI access log
The location of the log depends on the configuration of OUTPUT_DIR in rseapi.env:
$OUTPUT_DIR/rseapi_<port>.1/localhost_access_log.<date>.txt
A successful connection looks like:
1.2.3.4 - - [14/May/2025:10:16:45 -0400] "GET /rseapi/api/v1/info/serverdetails HTTP/1.1" 200 307
1.2.3.4 - - [14/May/2025:10:16:45 -0400] "POST /rseapi/api/v1/licenses/registerProduct HTTP/1.1" 200 1019
1.2.3.4 - - [14/May/2025:10:16:46 -0400] "GET /rseapi/api/v1/datasets/sys1.proclib HTTP/1.1" 200 590
9.8.7.6 - - [14/May/2025:10:16:47 -0400] "POST /rseapi/api/v1/auth/login HTTP/1.1" 204 -
9.8.7.6 - - [14/May/2025:10:16:47 -0400] "POST /rseapi/api/v1/licenses/registerProduct HTTP/1.1" 200 1019
1.2.3.4 - - [14/May/2025:10:16:47 -0400] "POST /rceapp/rcelogin/ HTTP/1.1" 200 170
1.2.3.4 - - [14/May/2025:10:16:52 -0400] "-" 400 -
1.2.3.4 - - [14/May/2025:10:16:52 -0400] "-" 400 -
1.2.3.4 - - [14/May/2025:10:17:09 -0400] "-" 400 -
1.2.3.4 - - [14/May/2025:10:17:09 -0400] "-" 400 -
1.2.3.4 - - [14/May/2025:10:17:09 -0400] "GET /rceapp?profileid=ProfileId&envid=vscode_tomcat&loginid=Z2F1bmVhdSMxNzQ3MjYxMDA3MDAwIzY4NDE3Mg==&win=true&lang=en HTTP/1.1" 302 -
1.2.3.4 - - [14/May/2025:10:17:09 -0400] "GET /rceapp/?profileid=ProfileId&envid=vscode_tomcat&loginid=Z2F1bmVhdSMxNzQ3MjYxMDA3MDAwIzY4NDE3Mg==&win=true&lang=en HTTP/1.1" 200 896
1.2.3.4 - - [14/May/2025:10:17:10 -0400] "GET /rceapp/static/js/main.755be7ad.js HTTP/1.1" 200 842304
* 1.2.3.4 and 9.8.7.6 are IP addresses
6) RSEAPI catalina log with RCE HTTP traces enabled
- Add the following statement to your rseapi.env:
#trace HTTP requests from rceapp to rseapi in catalina.log
JAVA_OPTS="$JAVA_OPTS -Djdk.httpclient.HttpClient.log=errors,requests,headers"
- Restart the RSEAPI started task
- Reproduce the problem
- Collect the catalina log which location depends on the configuration of OUTPUT_DIR in rseapi.env:
$OUTPUT_DIR/rseapi_<port>.1/catalina.<date>.log
Example of traces:
17-Jun-2025 07:51:53.275 INFO [HttpClient-1-Worker-0] jdk.internal.net.http.Http1Request.logHeaders HEADERS: REQUEST HEADERS:
POST /rseapi/api/v1/auth/login HTTP/1.1
Content-Length: 42
Host: host1.ibm.com:6834
User-Agent: Java-http-client/11.0.23
Accept: application/json
Content-Type: application/json
17-Jun-2025 07:51:53.523 INFO [HttpClient-1-Worker-0] jdk.internal.net.http.Http1Response.lambda$readHeadersAsync$0 HEADERS: RESPONSE HEADERS:
authorization: Bearer eyJhbGci......
date: Tue, 17 Jun 2025 11:51:53 GMT
set-cookie: apimlAuthenticationToken=eyJhbGci.......;Version=1
strict-transport-security: max-age=0
token-expiration-time: Tue Jun 17 15:51:53 EDT 2025
vary: Origin
x-content-type-options: nosniff
x-frame-options: DENY
x-xss-protection: 1; mode=block
Related Information
[{"Type":"MASTER","Line of Business":{"code":"LOB70","label":"Z TPS"},"Business Unit":{"code":"BU048","label":"IBM Software"},"Product":{"code":"SSTRMM","label":"IBM Developer for z\/OS"},"ARM Category":[{"code":"a8mKe000000002gIAA","label":"IBM Developer for Z\/OS-\u003ETerminal Emulator (RCE)"}],"ARM Case Number":"","Platform":[{"code":"PF033","label":"Windows"}],"Version":"17.0.0"}]
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Document Information
Modified date:
17 June 2025
UID
ibm16514447