WHICH ARTIFACT RETRIEVAL AGENT DID MY JOB USE?
If your artifacts are configured to use an artifact retrieval group then there is no way to see (in the ROC/ASAP UI) which retrieval agent from that group was used for that job. The only exception is if the error during artifact distribution tells you which artifact retrieval agent was used. It sometimes does, but not always. It depends on the error and whether or not the problem was related to the retrieval agent. But the logs from the retrieval agent are almost always needed for artifact distribution problems. You can identify which artifact retrieval agent is being used by a job by looking at the nolio_dm_all.log* files on the management server. If the logs have not been overwritten then there should be the following messages:
2017-02-10 20:24:21,033 [StageExecutorTask-8] INFO (com.nolio.releasecenter.services.release.execution.engine.ArtifactPackageDistributionServiceImpl:96) - Downloading artifacts to retrieval agents for [Artifact_Package_1] for deployment [Deploy1Artifact-2 ID.3].
2017-02-10 20:24:21,033 [StageExecutorTask-8] INFO (com.nolio.releasecenter.services.release.execution.engine.ArtifactsEngineImpl:313) - collecting data to download  artifacts to retrieval agents for release id 
2017-02-10 20:24:21,035 [StageExecutorTask-8] INFO (com.nolio.releasecenter.services.release.execution.engine.ArtifactsEngineImpl:467) - Artifact [ Artifact_Def_1.Artifact_Type_1'ver. Artifact_Ver_1'] Will be retrieved by the agent [ra552-nag1]
In the first message you can see the job name and release id. But another piece of important information is the thread (StageExecutorTask-8) as it will likely be the same thread that is used in the second and third message. The third message is showing which artifact retrieval agent (in this case: ra552-nag1) is being used to retrieve the artifact (in this case: Artifact_Ver_1).