ALTER TABLE DROP PRIMARY KEY never completes

Stage: 3 of 4 'After apply log event' 1.65e+04% of stage done

Stage: 3 of 4 'After apply log event' 1.11e+04% of stage done

Stage: 3 of 4 'After apply log event'    102% of stage done  

Stage: 3 of 4 'After apply log event' 6.26e+03% of stage done

Stage: 3 of 4 'After apply log event' 2.73e+03% of stage done

Stage: 4 of 4 'After apply log event' 1.56e+04% of stage done

Stage: 4 of 4 'After apply log event' 1.64e+04% of stage done

MariaDB [tpcc]> show processlist;

+-----+---------+-----------------+------+-------------+-------+---------------------------------------------------------------+----------------------------------------------+----------+

| Id  | User    | Host            | db   | Command     | Time  | State                                                         | Info                                         | Progress |

+-----+---------+-----------------+------+-------------+-------+---------------------------------------------------------------+----------------------------------------------+----------+

|   4 | maxuser | localhost:40510 | NULL | Binlog Dump | 13237 | Master has sent all binlog to slave; waiting for more updates | NULL                                         |    0.000 |

|   5 | maxuser | localhost:40514 | NULL | Binlog Dump | 13237 | Master has sent all binlog to slave; waiting for more updates | NULL                                         |    0.000 |

|   7 | maxuser | localhost:40520 | NULL | Binlog Dump | 13236 | Master has sent all binlog to slave; waiting for more updates | NULL                                         |    0.000 |

| 108 | maxuser | localhost:50372 | tpcc | Query       |  1477 | Update_rows_log_event::find_row()                             | alter table tpcc.order_line drop primary key |  100.000 |

| 183 | maxuser | localhost:42854 | NULL | Sleep       |     2 |                                                               | NULL                                         |    0.000 |

| 184 | maxuser | localhost:33074 | tpcc | Query       |     0 | starting                                                      | show processlist                             |    0.000 |

+-----+---------+-----------------+------+-------------+-------+---------------------------------------------------------------+----------------------------------------------+----------+

6 rows in set (0.000 sec)

MariaDB [tpcc]> show create table order_line\G

*************************** 1. row ***************************

       Table: order_line

Create Table: CREATE TABLE `order_line` (

  `ol_w_id` int(11) NOT NULL,

  `ol_d_id` int(11) NOT NULL,

  `ol_o_id` int(11) NOT NULL,

  `ol_number` int(11) NOT NULL,

  `ol_i_id` int(11) DEFAULT NULL,

  `ol_delivery_d` datetime DEFAULT NULL,

  `ol_amount` int(11) DEFAULT NULL,

  `ol_supply_w_id` int(11) DEFAULT NULL,

  `ol_quantity` int(11) DEFAULT NULL,

  `ol_dist_info` char(24) CHARACTER SET latin1 COLLATE latin1_bin DEFAULT NULL

) ENGINE=InnoDB DEFAULT CHARSET=latin1 COLLATE=latin1_swedish_ci

1 row in set (0.000 sec)

[Switching to thread 12 (LWP 3544396)]

#0  0x0000556601f73cf1 in buf_page_optimistic_fix(buf_block_t*, page_id_t) ()

#0  0x0000556601f73cf1 in buf_page_optimistic_fix(buf_block_t*, page_id_t) ()

#1  0x000055660177e36a in btr_pcur_optimistic_latch_leaves(btr_pcur_t*, btr_latch_mode*, mtr_t*) ()

#2  0x0000556601f6daef in btr_pcur_t::restore_position(btr_latch_mode, mtr_t*) ()

#3  0x0000556601ef0446 in sel_restore_position_for_mysql(bool*, btr_latch_mode, btr_pcur_t*, bool, mtr_t*) [clone .constprop.0] ()

#4  0x0000556601ef7072 in row_search_mvcc(unsigned char*, page_cur_mode_t, row_prebuilt_t*, unsigned long, unsigned long) ()

#5  0x0000556601e2ef40 in ha_innobase::rnd_next(unsigned char*) ()

#6  0x0000556601b2c10f in handler::ha_rnd_next(unsigned char*) ()

#7  0x0000556601c7e392 in Rows_log_event::find_row(rpl_group_info*) ()

#8  0x0000556601c7e81f in Update_rows_log_event::do_exec_row(rpl_group_info*) ()

#9  0x0000556601c7244f in Rows_log_event::do_apply_event(rpl_group_info*) ()

#10 0x0000556601c6af5d in Log_event::apply_event(rpl_group_info*) ()

#11 0x000055660194cd34 in online_alter_read_from_binlog(THD*, rpl_group_info*, Cache_flip_event_log*, unsigned long long*) ()

#12 0x00005566019635ff in copy_data_between_tables(THD*, TABLE*, TABLE*, bool, unsigned int, st_order*, unsigned long long*, unsigned long long*, Alter_info*, Alter_table_ctx*, bool, unsigned long long) [clone .constprop.0] ()

#13 0x00005566019691cb in mysql_alter_table(THD*, st_mysql_const_lex_string const*, st_mysql_const_lex_string const*, Table_specification_st*, TABLE_LIST*, Recreate_info*, Alter_info*, unsigned int, st_order*, bool, bool) ()

#14 0x00005566019d6182 in Sql_cmd_alter_table::execute(THD*) ()

#15 0x00005566018a0fa6 in mysql_execute_command(THD*, bool) ()

#16 0x00005566018a2171 in mysql_parse(THD*, char*, unsigned int, Parser_state*) ()

#17 0x00005566018a4805 in dispatch_command(enum_server_command, THD*, char*, unsigned int, bool) ()

#18 0x00005566018a663d in do_command(THD*, bool) ()

#19 0x0000556601aab817 in tp_callback(TP_connection*) ()

#20 0x0000556601cc4c2d in worker_main(void*) ()

#21 0x0000556601d6b199 in pfs_spawn_thread ()

#22 0x00007f01ade8b2ea in start_thread () from target:/lib64/libc.so.6

#23 0x00007f01adf0f5e4 in clone () from target:/lib64/libc.so.6