IBM Support

Plug-ins are not picked up from the dropins/ folder



You prepared IBM product extensions in the form of Eclipse plug-ins. Then you deployed them to the dropins/ folder. This folder is under management of the Eclipse component Provisioning Platform (P2). The problem is that the IBM Eclipse-based product ignores the plug-ins. This technote contains two proposals to search the cause.


A possible cause is that you reached the known dropins/ folder limitations.

Resolving The Problem

Verify if a known dropins/folder issue affects you.

  1. Create a bogus plug-in with no dependencies and no content.
  2. Then you deploy it into dropins/ folder.
  3. Verify if Eclipse picks up the bogus plug-in correctly.
  4. Verify if you can see the plug-in in the Plug-in Registry view,
  5. Continue with the investigation of your plug-ins.

However, if Eclipse does not pick up the bogus plug-in, you reached the known dropins/folder limitations.

Note: Eclipse P2 scans only dropins/ folder for updated folders until Rational Application Developer for WebSphere Software and Rational Software Architect Eclipse does not look in subfolders. Therefore you need to invoke IBM software with the -clean parameter. The same limitation applies to the .link files.

You can also create an update site and try to install your plug-ins with the P2 user interface. P2 will diagnose eventual problems.

The following steps enable dropins debugging.

  1. Create a file name .options in the main IBM software installation directory, where eclipse.exe (or other system equivalent) is located. The file should contain following lines:


  2. Replace javaw with java inside eclipse.ini
  3. Add startup options -debug and -console
  4. Modify dropins/folder, f.e. add bogus plug-in or touch any existing plug-in to cause dropins/reconciliation.

The process consists of three major phases.
  1. Discovering changes,
  2. creating a request,
  3. creating a plan.

I. Discovering changes
During this phase P2 scans dropins folder to discover changes. The same applies to other folders that depend on the P2 configuration.

[p2] Mon Apr 19 12:24:19 EDT 2010 - [Start Level Event Dispatcher] [reconciler] [dropins] Interesting feature or bundle added: C:\<installation path>\SDP\dropins\ABC_1.0.0.201004191222.jar

This message means that P2 discovered plug-in ABC_1.0.0.201004191222.jar in the dropins folder. If you made the modification to the file system, but the change is invisible, you need to start the IBM product with the -clean parameter. If this does not help, verify, if your dropins folder organization is supported.

II. Creating a request
After gathering all user changes, P2 tries to create so called "request". This consists of all the changes that you want to make in the installation. At this point this is no longer talking a file system modification, but rather a particular plug-in installation or uninstallation.

[p2] Mon Apr 19 12:24:20 EDT 2010 - [Start Level Event Dispatcher] [reconciler] Adding IU: ABC

[p2] Mon Apr 19 12:24:20 EDT 2010 - [Start Level Event Dispatcher] [reconciler] Adding IU property: ABC
22->{org.eclipse.equinox.p2.type.lock=1, org.eclipse.equinox.p2.internal.inclusion.rules=OPTIONAL,

Those two messages say that the aforementioned plug-in is included into the further processing. Pay attention to attributes. The plug-in is marked as optional, and it is clearly indicated that it comes from the dropins folder.

[p2] Mon Apr 19 12:24:20 EDT 2010 - [Start Level Event Dispatcher] [reconciler] No installable units to remove.

<code>] [p2] Mon Apr 19 12:24:20 EDT 2010 - [Start Level Event Dispatcher] [reconciler] No IU properties to remove.

Those two messages means that no plug-in will be uninstalled and no plug-in property will be removed.

III. Creating a plan
Once P2 knows what the user want to achieve, it computes a "plan". This plan consists of installation/uninstallation operations that are necessary to install plug-ins.

[p2] Mon Apr 19 12:24:20 EDT 2010 - [Start Level Event Dispatcher] [reconciler] [plan] Plan matches the request.

This is very important message. It means that all plug-ins that you added for processing or removal will be processed and installed or removed. Alternatively you can get following self-explaining message

[p2] Mon Apr 19 12:30:34 EDT 2010 - [Start Level Event Dispatcher] [reconciler] [plan] Some units will not be installed, because they are already installed or there are dependency issues:

[p2] Mon Apr 19 12:30:34 EDT 2010 - [Start Level Event Dispatcher] [reconciler] [plan] asfd

Unfortunately it is impossible to discover what went wrong exactly. Therefore you are responsible for providing the plug-ins that you can install successfully in the environment.

Those debug information does not show exactly the source of the problems. However, you can exclude certain causes and narrow down the area of research. For example, not discovering the file system change, or unsatisfied dependency.

Note: Service Release is the first release with dropins debugging.

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Document Information

Modified date:
16 June 2018