statement:ALTER TABLE _100 DROP PRIMARY KEY, ADD UNIQUE KEY uidx_mobile_userid(id,a);

2018-10-09 12:02:39 INFO starting gh-ost 1.0.46
2018-10-09 12:02:39 INFO Migrating test._100
2018-10-09 12:02:39 INFO connection validated on 10.17.4.23:3307
2018-10-09 12:02:39 INFO User has ALL privileges
2018-10-09 12:02:39 INFO binary logs validated on 10.17.4.23:3307
2018-10-09 12:02:39 INFO Restarting replication on 10.17.4.23:3307 to make sure binlog settings apply to replication thread
2018-10-09 12:02:39 INFO Inspector initiated on DEV_10_17_4_23:3307, version 5.5.19-log
2018-10-09 12:02:39 INFO Table found. Engine=InnoDB
2018-10-09 12:02:39 WARNING --skip-foreign-key-checks provided: will not check for foreign keys
2018-10-09 12:02:39 INFO Estimated number of rows via EXPLAIN: 2
2018-10-09 12:02:39 INFO Recursively searching for replication master
2018-10-09 12:02:39 INFO Master found to be DEV_10_17_4_23:3307
2018-10-09 12:02:39 INFO log_slave_updates validated on 10.17.4.23:3307
2018-10-09 12:02:39 INFO connection validated on 10.17.4.23:3307
2018/10/09 12:02:39 binlogsyncer.go:79: ^[[0;37m[info] create BinlogSyncer with config {99999 mysql 10.17.4.23 3307 ghost false false }^[[0m
2018-10-09 12:02:39 INFO Connecting binlog streamer at binlog.000004:85784
2018/10/09 12:02:39 binlogsyncer.go:246: ^[[0;37m[info] begin to sync binlog from position (binlog.000004, 85784)^[[0m
2018/10/09 12:02:39 binlogsyncer.go:139: ^[[0;37m[info] register slave for master server 10.17.4.23:3307^[[0m
2018/10/09 12:02:39 binlogsyncer.go:573: ^[[0;37m[info] rotate to (binlog.000004, 85784)^[[0m
2018-10-09 12:02:39 INFO rotate to next log name: binlog.000004
2018-10-09 12:02:39 INFO connection validated on 10.17.4.23:3307
2018-10-09 12:02:39 INFO connection validated on 10.17.4.23:3307
2018-10-09 12:02:39 INFO will use time_zone='SYSTEM' on applier
2018-10-09 12:02:39 INFO Examining table structure on applier
2018-10-09 12:02:39 INFO Applier initiated on DEV_10_17_4_23:3307, version 5.5.19-log
2018-10-09 12:02:39 INFO Dropping table test.__100_gho
2018-10-09 12:02:39 INFO Table dropped
2018-10-09 12:02:39 INFO Dropping table test.__100_del
2018-10-09 12:02:39 INFO Table dropped
2018-10-09 12:02:39 INFO Dropping table test.__100_ghc
2018-10-09 12:02:39 INFO Table dropped
2018-10-09 12:02:39 INFO Creating changelog table test.__100_ghc
2018-10-09 12:02:39 INFO Changelog table created
2018-10-09 12:02:39 INFO Creating ghost table test.__100_gho
2018-10-09 12:02:39 INFO Ghost table created
2018-10-09 12:02:39 INFO Altering ghost table test.__100_gho
2018-10-09 12:02:40 INFO Ghost table altered
2018-10-09 12:02:40 INFO Intercepted changelog state GhostTableMigrated
2018-10-09 12:02:40 INFO Waiting for ghost table to be migrated. Current lag is 0s
2018-10-09 12:02:40 INFO Handled changelog state GhostTableMigrated
2018-10-09 12:02:40 INFO Tearing down inspector
2018-10-09 12:02:40 INFO Tearing down applier
2018-10-09 12:02:40 INFO Tearing down streamer
2018-10-09 12:02:40 FATAL No shared unique key can be found after ALTER! Bailing out