HMGR0149E: An attempt to open a connection to core group DefaultCoreGroup has been rejected.

Problem

HMGR0149E: An attempt to open a connection to core group DefaultCoreGroup has been rejected.

Symptom

HMGR0149E: An attempt to open a connection to core group DefaultCoreGroup has been rejected. The sending process has a name of myplex1\nodea\nodeagent and an IP address of /123.456.115.115. Global security in the local process is Disabled. Global security in the sending process is Disabled. The received token starts with ab1c234:56abc7848e4:-8000. The exception is <null>

So, when I tried to sync node, I got the above error. Found this IBM Technote
http://www-01.ibm.com/support/docview.wss?uid=swg21596835

Per this technote, the solution is -

Resolving the problem

Resolve LTPA token mismatch or remove DCS_SECURE setting.

The DCS_SECURE setting can be removed by changing the Transport chain for the coregroup.

1. In the administrative console, click Servers > Core groups > Core group settings and select the respective core group

2. Under Transport type > Channel Framework
change the transport chain from DCS_SECURE to DCS

When checked in my config, it transport Type > Channel Framework > Transport chain was set to DCS.

I manually did a syncNode on the server process, got it fixed. Here is the procedure -

1. Stop Server

2. Stop Node

3. From the Node, issue syncNode like this
D:\IBM\WebSphere\AppServer\profiles\AppSrv01\bin>syncNode <dmgrnode> -conntype
 SOAP -username <adminuid> -password <adminpassword>

This command syncs the node with the DMGR.
ADMU0116I: Tool information is being logged in file
           D:\IBM\WebSphere\AppServer\profiles\AppSrv01\logs\syncNode.log
ADMU0128I: Starting tool with the AppSrv01 profile
ADMU0401I: Begin syncNode operation for node DMGRNode01 with Deployment
           Manager dmgr: 8879
ADMU0016I: Synchronizing configuration between node and cell.
ADMU0402I: The configuration for node DMGRNode01 has been synchronized
           with Deployment Manager dmgr: 8879

Once this command executes,

4. start the node agent

5. start server

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Thanks and Regards
Bhaskar Ramaraju
http://www.linkedin.com/in/ramarajubhaskar

A composition unit with name MyApp already exists. Select a different application name.

Problem(Abstract)

A composition unit with name MyApp already exists. Select a different application name.

Cause

This is most frequently observed during the installation or removal of applications, but it may also turn up during other administration tasks such as deleting servers.
The issue maybe caused by WebSphere Application Server APAR PM20642.

In this scenario, if there is an error with the deployment of a module, then this bad deployment is saved, then the WebSphere Application Server configuration will be out of sync.

In WebSphere Process Server, this often happens with a module that has WebSphere Business Integration Adapter Resources that might not be complete or set up properly.
When deploying using WebSphere Integration Developer using "Add Projects", the configuration changes for this bad deployment are automatically saved.

Even after the application is removed, you might not be able to do any further or new application installs or uninstalls (even with a corrected module).

Resolving the problem

The manual workaround is to delete the /blas and /cus directories for the bad application from the configuration.
The resources will be located in the config directory of the profile.:

<profile name>/config/cells/qcell/blas
<profile name>/config/cells/qcell/cus

http://www-01.ibm.com/support/docview.wss?uid=swg21455322
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Thanks and Regards
Bhaskar Ramaraju
http://www.linkedin.com/in/ramarajubhaskar

Ideal WAS Environment