[HDFS-11294] libhdfs++: Segfault in HA failover if DNS lookup for both Namenodes fails

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Component/s: hdfs-client
• Assignee: James Clampffer
• Reporter: James Clampffer
• Created: 05/Jan/17 17:05
• Updated: 22/Mar/18 21:58
• Resolved: 30/Oct/17 16:08

Description

Hit while doing more manual testing on HDFS-11028.

The HANamenodeTracker takes an asio endpoint to figure out what endpoint on the other node to try next during a failover. This is done by passing the element at index 0 from endpoints (a std::vector<asio endpoint>).

When DNS fails the endpoints vector for that node will be empty so the iterator returned by endpoints[0] is just a null pointer that gets dereferenced and causes a segfault.