percona-server-5.6-5.6.27-76.0/storage/innobase/btr/btr0sea.cc line 705

MySQL & MariaDB Other MySQL® Questions
1

Last time write locked in file /mnt/workspace/percona-server-5.6-debian-binary/label_exp/ubuntu-trusty-64bit/percona-server-5.6-5.6.27-76.0/storage/innobase/btr/btr0sea.cc line 705
–Thread 140629718189824 has waited at row0ins.cc line 2718 for 1.0000 seconds the semaphore:
X-lock on RW-latch at 0x7feae0f2c640 ‘&block->lock’
a writer (thread id 140629766379264) has reserved it in mode exclusive
number of readers 0, waiters flag 1, lock_word: 0
Last time read locked in file buf0flu.cc line 1078

Last time write locked in file /mnt/workspace/percona-server-5.6-debian-binary/label_exp/ubuntu-trusty-64bit/percona-server-5.6-5.6.27-76.0/storage/innobase/row/row0ins.cc line 2718
–Thread 140633553512192 has waited at row0ins.cc line 2718 for 1.0000 seconds the semaphore:
X-lock on RW-latch at 0x7feae0f2c640 ‘&block->lock’
a writer (thread id 140629766379264) has reserved it in mode exclusive
number of readers 0, waiters flag 1, lock_word: 0
Last time read locked in file buf0flu.cc line 1078

Can you please mention what is the issue here?

2

I seem to have the same issue here… Is there a filed bug for this?
Thanks

3

Looks like you are having too much concurrency and therefore some threads have to wait on mutexes. This one:

rw_lock_x_lock(btr_search_get_latch(cursor->index));

Semaphores and low waits are normal if many threads try to access the same data. With the info shared it is not possible to give an detailed reply, but I would recommend you to test limiting innodb_thread_concurrency to the number of cores. Also, I would recommend you to upgrade to latest version. The one you are running is two years old. Tons of bug has been fixed and performance improvements applied since then.