[GIRAPH-1036] Allow mappers to fail early on exceptions

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.2.0
• Assignee: Maja Kabiljo
• Reporter: Maja Kabiljo
• Created: 21/Oct/15 01:19
• Updated: 14/Oct/16 00:58
• Resolved: 06/May/16 18:16

Description

Often when something fails in a mapper we see it stuck until its timeout passes. Digging through this issue I found two root causes:

• Many threads we are creating were not daemon, preventing process to exit, only main thread should be daemon
• When calling submit on ExecutorService, exceptions are not propagated back to the caller, unless get is called on the future. In ProgressableUtils.getResultsWithNCallables we were calling get on one by one future, causing us to have to wait for previous futures to finish before getting exception which happened in later one.