[ACCUMULO-1723] monitor service GET / hangs if Zookeeper down

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Duplicate
• Affects Version/s: 1.6.0
• Component/s: monitor

Environment

small pseudo-cluster where the single-node ZK has been shut down

• Assignee: Unassigned
• Reporter: Steve Loughran
• Created: 19/Sep/13 11:35
• Updated: 22/Apr/14 20:39
• Resolved: 22/Apr/14 20:39

Description

Once ZK is offline, you can't issue GET (or POST or HEAD, but not PUT) requests against URLs on the monitors web port. The requests just hang. Invalid HTTP requests get rejected by Jetty, so the process itself is running, it's just whatever servlet is fielding requests is blocking without timeouts waiting for ZK, or for a lock to be released by some other thread that is blocked on ZK.

While a ZK outage is not something you'd plan for in a real cluster, it is the kind of thing you'd hope the monitor to pick up and explicit highlight as a problem -especially if the page is being fetched by a machine process rather than an individual

Issue Links

• duplicates: ACCUMULO-2481 Monitor should still work if HDFS + Zookeeper go away