Bug #77319 InnoDB: Warning: a long semaphore wait:Thread xxx has waited at trx0
Submitted: 11 Jun 2015 15:03 Modified: 14 Oct 2019 19:22
Reporter: mohamed harraz Email Updates:
Status: No Feedback Impact on me:
None 
Category:MySQL Server Severity:S3 (Non-critical)
Version:5.6.25 OS:Linux
Assigned to: CPU Architecture:Any
Tags: Semaphore

[11 Jun 2015 15:03] mohamed harraz
Description:
One of my load jobs crashed over night, this is a new server I just configured, so it may be the default settings are not good enough, but looking at the log below I can't tell what to change or adjust in the server settings to avoid this crash

InnoDB: Warning: a long semaphore wait:
--Thread 140019116971776 has waited at trx0undo.ic line 171 for 241.00 seconds the semaphore:
X-lock (wait_ex) on RW-latch at 0x7f58c4ec4540 created in file buf0buf.cc line 1065
a writer (thread id 140019116971776) has reserved it in mode  wait exclusive
number of readers 1, waiters flag 0, lock_word: ffffffffffffffff
Last time read locked in file buf0flu.cc line 1056
Last time write locked in file /export/home/pb2/build/sb_0-15205200-1430829639.81/rpm/BUILD/mysql-5.6.25/mysql-5.6.25/storage/innobase/trx/trx0rec.cc line 1295
InnoDB: ###### Starts InnoDB Monitor for 30 secs to print diagnostic info:
InnoDB: Pending preads 0, pwrites 0

I have more details from the InnoDB monitor but its' too long to fit here

How to repeat:
Inset 11 million records in a table. The table is empty and no updates are taking places
[11 Jun 2015 15:04] mohamed harraz
INNODB MONITOR OUTPUT from the server log

Attachment: INNODB MONITOR OUTPUT.txt (text/plain), 18.09 KiB.

[11 Jun 2015 15:05] mohamed harraz
server variables

Attachment: server variables.txt (text/plain), 11.98 KiB.

[14 Sep 2019 19:22] MySQL Verification Team
Please check with latest release, probably already fixed.
[15 Oct 2019 1:00] Bugs System
No feedback was provided for this bug for over a month, so it is
being suspended automatically. If you are able to provide the
information that was originally requested, please do so and change
the status of the bug back to "Open".