Bug #117445 mysql hang
Submitted: 12 Feb 3:44 Modified: 12 Feb 14:01
Reporter: 明 曹 Email Updates:
Status: Unsupported Impact on me:
None 
Category:MySQL Server Severity:S2 (Serious)
Version:5.7.27 OS:Linux
Assigned to: CPU Architecture:x86
Tags: max connections

[12 Feb 3:44] 明 曹 
Description:
2025-02-11T21:21:49.118564+08:00 0 [Warning] InnoDB: A long semaphore wait:
--Thread 140159750592256 has waited at row0ins.cc line 2510 for 272  seconds the semaphore:
X-lock on RW-latch at 0x7f76df45aeb0 created in file buf0buf.cc line 1481
a writer (thread id 140160152549120) has reserved it in mode  exclusive
number of readers 0, waiters flag 1, lock_word: 0
Last time read locked in file row0sel.cc line 3775
Last time write locked in file /data/fuxi_ci_workspace/5e23e4fb37d87a00083e0ce2/storage/innobase/btr/btr0sea.cc line 1035
2025-02-11T21:21:49.118583+08:00 0 [Warning] InnoDB: A long semaphore wait:
--Thread 140133207054080 has waited at dict0dict.cc line 1362 for 254  seconds the semaphore:
Mutex at 0x7f79920f3218, Mutex DICT_SYS created dict0dict.cc:1294, lock var 1

How to repeat:
no

Suggested fix:
no
[12 Feb 14:01] MySQL Verification Team 
Hi Mr. 明 曹,

Thank you for your bug report.

However, version 5.7 is not supported for already couple of years.

Also, what you get is a long semaphore wait, which is explained in our Reference Manual.

Unsupported.