It eventually started after about 20 minutes (/var/log/mysql/mysql.log):
...
2015-08-04 00:29:46 23639 [Note] InnoDB: Completed initialization of buffer pool
2015-08-04 00:29:47 23639 [Note] InnoDB: Highest supported file format is Barracuda.
2015-08-04 00:49:36 23639 [Note] InnoDB: 128 rollback segment(s) are active.
...
2015-08-04 00:49:38 23639 [Note] /usr/sbin/mysqld: ready for connections.
It looks like this is related to open_files_limit in conjunction with the number of databases when performance_schema is enabled.
I've just tested this on our staging platform with 219794 tables
Server version: 5.6.25-73.1-log Percona Server (GPL), Release 73.1, Revision 07b797f
# grep -iE '(performance_ schema| open_files_ limit)' /etc/mysql/my.cnf; date; /etc/init.d/mysql start; date limit=4000000 schema= OFF
open_files_
performance_
Tue Aug 4 00:26:39 CDT 2015
Starting MySQL (Percona Server) database server: mysqld . . . . . . . . . . ..
Checking for corrupt, not cleanly closed and upgrade needing tables..
Tue Aug 4 00:26:52 CDT 2015
# grep -iE '(performance_ schema| open_files_ limit)' /etc/mysql/my.cnf; date; /etc/init.d/mysql start; date limit=4000000 schema= ON
open_files_
performance_
Tue Aug 4 00:29:27 CDT 2015
Starting MySQL (Percona Server) database server: mysqld . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . failed!
Tue Aug 4 00:44:53 CDT 2015
It eventually started after about 20 minutes (/var/log/ mysql/mysql. log):
...
2015-08-04 00:29:46 23639 [Note] InnoDB: Completed initialization of buffer pool
2015-08-04 00:29:47 23639 [Note] InnoDB: Highest supported file format is Barracuda.
2015-08-04 00:49:36 23639 [Note] InnoDB: 128 rollback segment(s) are active.
...
2015-08-04 00:49:38 23639 [Note] /usr/sbin/mysqld: ready for connections.
It looks like this is related to open_files_limit in conjunction with the number of databases when performance_schema is enabled.