LP #1570114: Long running ALTER TABLE ADD INDEX causes semaphore wait > 600 assertion

**Reported in Launchpad by monty solomon last update 13-12-2016 04:16:54

MySQL crashed and suggested I submit a bug report.

InnoDB: Error: semaphore wait has lasted > 600 seconds
InnoDB: We intentionally crash the server, because it appears to be hung.

mysql Ver 14.14 Distrib 5.6.25-73.1, for Linux (x86_64) using 6.0
5.6.25-73.1-log Percona Server (GPL), Release 73.1, Revision 07b797f

Linux plain-union 3.18.26-83.el6.x86_64 #1 SMP Mon Jan 25 18:39:22 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

CentOS release 6.7 (Final)