[REEF-292] Improve details for InjectionException in Tang.NET

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: Tang.NET
• Assignee: Julia Wang
• Reporter: Markus Weimer
• Created: 29/Apr/15 14:58
• Updated: 29/Apr/15 17:13

Description

InjectionException in Tang is thrown when it cannot instantiate a type. The current exception contains the type which couldn't be instantiated, but little more detail. This can make debugging harder than it needs to be (see REEF-276 for an example).

We should improve Tang to throw specific exceptions for all the reasons why injection could fail. These include:

1. The type to instantiate is unknown. We should differentiate the cases where the assembly which should contain it was loaded or not. In the cases where it was not, the exception should contain the reason, e.g. file not found or unable to read or such.
2. The type has no injectable constructors at all. This captures the common case of missing attributes.
3. The type has injectable constructors, but the configuration provided isn't complete enough to satisfy any of them.

Issue Links

• is related to: REEF-276 Requesting 100 Containers on YARN causes injection errors in submitting tasks on REEF.NET on HDInsight