| OSGi Service Diagnostics and WebConsole Plugin |
| ============================================== |
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| This projects aims at easing diagnostics of OSGi services and finding about missing and/or circular dependencies. |
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| Typically in a large system with many cascading dependencies managed by different trackers such as DeclarativeService, DependencyManager or others, tracking the root cause of a top level service not being started can become very cumbersome. When building service oriented architectures, it is often the case that a single missing requirement will lock a full stack of services, but to find that one requirement is like finding a needle in a haystack! |
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| The basic idea here is to ask each dependency manager instance about its unresolved dependencies, merge all answers and filter the result to keep only the root causes. |
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| Typically, if A depends on B which depends on C which depends on D, and D is nowhere to be found, I need only show the "C -> D" missing requirement; if D is resolved, then the whole stack is unlocked. |
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| Similarly, if D is known by another dependency management system, but unregistered because it depends on E which is missing, then only the "D -> E" requirement is relevant. |
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| Project organization (core): |
| ============================ |
| * servicediagnostics: the API package. It holds the main service interface as well as the plugin interface, to extend to other dependency management systems |
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| * servicediagnostics.impl: the implementation package. It contains plugins implementations for org.apache.felix.scr and org.apache.felix.dependencymanager, as well as the main service implementation. |
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| * servicediagnostics.webconsole: a Felix WebConsole plugin that displays a graphical view of the diagnostics result. Alternatively it can also show a graph of all services currently registered in the service registry and the bundles using them. See Screenshot-notavail.png and Screenshot-all.png. |
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| The "sample" part simply contains some test classes and a helper class to launch Felix. |
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| How to build the project: |
| ========================= |
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| > mvn install |
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| How to run: |
| =========== |
| I'm providing a simple run script just to try out the service. |
| > ./run.sh |
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| It should display: |
| [INFO] Started jetty 6.1.x at port(s) HTTP:8080 |
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| You can then point your browser to |
| http://localhost:8080/system/console/servicegraph |
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| (login/password is admin/admin) |
| then click on either "Show Not Avail" or "Show Service Registry" |
| The nodes can be dragged around for better readability. The colors are random and don't mean anything. |
| On the "Service Registry" view, arrows point from bundles to the services they use. |
| On the "Not Avail" view, arrows point from a leaf component to its missing dependencies. |
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| (note: the lib directory is provided for dependencies that are not readily available as OSGi bundles from maven) |
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| Issues & TODOs: |
| =============== |
| * no support for iPojo, Blueprint, basic ServiceTrackers... more plugins could be developed. I only wrote the ones i'm using. |
| * should package proper tests |