Mariadb becomes unresponsive

10.2.9-MariaDB-10.2.9+maria~trusty-log

2017-10-03 10:21:11 140203119265536 [Note] InnoDB: A semaphore wait:

--Thread 140200436983552 has waited at read0read.cc line 579 for 303.00 seconds the semaphore:

Mutex at 0x7f8fced4d2b0, Mutex TRX_SYS created trx0sys.cc:558, lock var 2

2017-10-03 10:21:11 140203119265536 [Note] InnoDB: A semaphore wait:

--Thread 140202383660800 has waited at lock0lock.cc line 7784 for 303.00 seconds the semaphore:

Mutex at 0x7f8fceccddc0, Mutex LOCK_SYS created lock0lock.cc:495, lock var 2

2017-10-03 10:21:11 140203119265536 [Note] InnoDB: A semaphore wait:

--Thread 140203085694720 has waited at read0read.cc line 687 for 303.00 seconds the semaphore:

Mutex at 0x7f8fced4d2b0, Mutex TRX_SYS created trx0sys.cc:558, lock var 2

2017-10-03 10:21:11 140203119265536 [Note] InnoDB: A semaphore wait:

--Thread 140200439097088 has waited at read0read.cc line 579 for 303.00 seconds the semaphore:

Mutex at 0x7f8fced4d2b0, Mutex TRX_SYS created trx0sys.cc:558, lock var 2

2017-10-03 10:21:11 140203119265536 [Note] InnoDB: A semaphore wait:

--Thread 140200431699712 has waited at lock0lock.cc line 5075 for 303.00 seconds the semaphore:

Mutex at 0x7f8fceccddc0, Mutex LOCK_SYS created lock0lock.cc:495, lock var 2

2017-10-03 10:21:11 140203119265536 [Note] InnoDB: A semaphore wait:

--Thread 140200429586176 has waited at read0read.cc line 579 for 303.00 seconds the semaphore:

Mutex at 0x7f8fced4d2b0, Mutex TRX_SYS created trx0sys.cc:558, lock var 2

2017-10-03 10:21:11 140203119265536 [Note] InnoDB: A semaphore wait:

--Thread 140200443324160 has waited at trx0trx.cc line 664 for 303.00 seconds the semaphore:

Mutex at 0x7f8fced4d2b0, Mutex TRX_SYS created trx0sys.cc:558, lock var 2

2017-10-03 10:21:11 140203119265536 [Note] InnoDB: A semaphore wait:

--Thread 140202384189184 has waited at read0read.cc line 579 for 301.00 seconds the semaphore:

Mutex at 0x7f8fced4d2b0, Mutex TRX_SYS created trx0sys.cc:558, lock var 2

2017-10-03 10:21:11 140203119265536 [Note] InnoDB: A semaphore wait:

--Thread 140200442267392 has waited at read0read.cc line 579 for 299.00 seconds the semaphore:

Mutex at 0x7f8fced4d2b0, Mutex TRX_SYS created trx0sys.cc:558, lock var 2

2017-10-03 10:21:11 140203119265536 [Note] InnoDB: A semaphore wait:

--Thread 140201363072768 has waited at read0read.cc line 579 for 299.00 seconds the semaphore:

Mutex at 0x7f8fced4d2b0, Mutex TRX_SYS created trx0sys.cc:558, lock var 2

2017-10-03 10:21:11 140203119265536 [Note] InnoDB: A semaphore wait:

--Thread 140200430114560 has waited at read0read.cc line 579 for 299.00 seconds the semaphore:

Mutex at 0x7f8fced4d2b0, Mutex TRX_SYS created trx0sys.cc:558, lock var 2

2017-10-03 10:21:11 140203119265536 [Note] InnoDB: A semaphore wait:

--Thread 140201362544384 has waited at trx0trx.cc line 3091 for 286.00 seconds the semaphore:

Mutex at 0x7f8fced4d2b0, Mutex TRX_SYS created trx0sys.cc:558, lock var 2

2017-10-03 10:21:11 140203119265536 [Note] InnoDB: A semaphore wait:

--Thread 140203127658240 has waited at lock0wait.cc line 484 for 282.00 seconds the semaphore:

Mutex at 0x7f8fceccddc0, Mutex LOCK_SYS created lock0lock.cc:495, lock var 2

2017-10-03 10:21:11 140203119265536 [Note] InnoDB: A semaphore wait:

--Thread 140203034810112 has waited at trx0trx.cc line 1275 for 242.00 seconds the semaphore:

Mutex at 0x7f8fced4d2b0, Mutex TRX_SYS created trx0sys.cc:558, lock var 2

2017-10-03 10:21:11 140203119265536 [Note] InnoDB: A semaphore wait:

--Thread 140203110872832 has waited at read0read.cc line 714 for 60.00 seconds the semaphore:

Mutex at 0x7f8fced4d2b0, Mutex TRX_SYS created trx0sys.cc:558, lock var 2

....