# Crash & restart of proxysql instances

**URL:** <https://forums.percona.com/t/crash-restart-of-proxysql-instances/31639>\
**Category:** ProxySQL\
**Created:** [July 16, 2024, 4:44pm UTC](https://forums.percona.com/t/crash-restart-of-proxysql-instances/31639 "2024-07-16T16:44:07Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![Alessandro\_Dentella](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/alessandro_dentella/32/15811_2.png) [@Alessandro\_Dentella](https://forums.percona.com/u/Alessandro_Dentella)\
**Post date:** [July 16, 2024, 4:44pm UTC](https://forums.percona.com/t/crash-restart-of-proxysql-instances/31639/1 "2024-07-16T16:44:07Z")

</div>

Hi,

this morning one of 3 proxysql processes on a server has problems that led to a crash and

The logs before the crash show a long series of unhealthy messages like this:

```auto
2024-07-16 04:03:25 MySQL_Thread.cpp:3895:process_all_sessions(): [WARNING] Closing unhealthy client connection 10.24.104.106:52808
2024-07-16 04:03:25 MySQL_Thread.cpp:3895:process_all_sessions(): [WARNING] Closing unhealthy client connection 10.24.104.106:52842
2024-07-16 04:03:25 MySQL_Thread.cpp:3895:process_all_sessions(): [WARNING] Closing unhealthy client connection 10.24.104.106:52858
2024-07-16 04:03:25 MySQL_Thread.cpp:3895:process_all_sessions(): [WARNING] Closing unhealthy client connection 10.24.104.106:52864
2024-07-16 04:03:25 MySQL_Thread.cpp:3895:process_all_sessions(): [WARNING] Closing unhealthy client connection 10.24.104.106:52892
2024-07-16 04:03:25 MySQL_Thread.cpp:3895:process_all_sessions(): [WARNING] Closing unhealthy client connection 10.24.104.106:52878
2024-07-16 04:03:25 MySQL_Thread.cpp:3895:process_all_sessions(): [WARNING] Closing unhealthy client connection 10.24.104.106:52918
2024-07-16 04:03:25 MySQL_Thread.cpp:3895:process_all_sessions(): [WARNING] Closing unhealthy client connection 10.24.104.106:52944
2024-07-16 04:03:25 MySQL_Thread.cpp:3895:process_all_sessions(): [WARNING] Closing unhealthy client connection 10.24.104.106:52976
2024-07-16 04:03:25 MySQL_Thread.cpp:3895:process_all_sessions(): [WARNING] Closing unhealthy client connection 10.24.104.106:52990
subsequent restart of the process.

```

followed by:

```auto
2024-07-16 09:17:28 MySQL_Thread.cpp:2854:create_new_session_and_client_data_stream(): [ERROR] For FD -1 fcntl() returned -1 errno 9
proxysql: MySQL_Thread.cpp:2856: MySQL_Session* MySQL_Thread::create_new_session_and_client_data_stream(int): Assertion `prevflags != -1' failed.
2024-07-16 09:17:28 MySQL_Thread.cpp:2854:create_new_session_and_client_data_stream(): [ERROR] For FD -1 fcntl() returned -1 errno 9
proxysql: MySQL_Thread.cpp:2856: MySQL_Session* MySQL_Thread::create_new_session_and_client_data_stream(int): Assertion `prevflags != -1' failed.
2024-07-16 09:17:28 MySQL_Thread.cpp:2854:create_new_session_and_client_data_stream(): [ERROR] For FD -1 fcntl() returned -1 errno 9
Error: signal 6:
proxysql: MySQL_Thread.cpp:2856: MySQL_Session* MySQL_Thread::create_new_session_and_client_data_stream(int): Assertion `prevflags != -1' failed.
Error: signal 6:
Error: signal 6:
2024-07-16 09:17:28 MySQL_Thread.cpp:2854:create_new_session_and_client_data_stream(): [ERROR] For FD -1 fcntl() returned -1 errno 9
proxysql: MySQL_Thread.cpp:2856: MySQL_Session* MySQL_Thread::create_new_session_and_client_data_stream(int): Assertion `prevflags != -1' failed.
/usr/bin/proxysql(_Z13crash_handleri+0x40)[0x55e7d41d3ae0]
2024-07-16 09:17:28 MySQL_Thread.cpp:2854:create_new_session_and_client_data_stream(): [ERROR] For FD -1 fcntl() returned -1 errno 9
proxysql: MySQL_Thread.cpp:2856: MySQL_Session* MySQL_Thread::create_new_session_and_client_data_stream(int): Assertion `prevflags != -1' failed.
Error: signal 6:
/lib/x86_64-linux-gnu/libc.so.6(+0x42520)[0x7fbff7e42520]
Error: signal 6:
2024-07-16 09:17:28 MySQL_Thread.cpp:2854:create_new_session_and_client_data_stream(): [ERROR] For FD -1 fcntl() returned -1 errno 9
proxysql: MySQL_Thread.cpp:2856: MySQL_Session* MySQL_Thread::create_new_session_and_client_data_stream(int): Assertion `prevflags != -1' failed.
Error: signal 6:
/usr/bin/proxysql(_Z13crash_handleri+0x40)[0x55e7d41d3ae0]
/lib/x86_64-linux-gnu/libc.so.6(+0x42520)[0x7fbff7e42520]
2024-07-16 09:17:28 MySQL_Thread.cpp:2854:create_new_session_and_client_data_stream(): [ERROR] For FD -1 fcntl() returned -1 errno 9
proxysql: MySQL_Thread.cpp:2856: MySQL_Session* MySQL_Thread::create_new_session_and_client_data_stream(int): Assertion `prevflags != -1' failed.
/lib/x86_64-linux-gnu/libc.so.6(pthread_kill+0x12c)[0x7fbff7e96a7c]

```

terminating with:

```2024-07-16
proxysql: MySQL_Thread.cpp:2856: MySQL_Session* MySQL_Thread::create_new_session_and_client_data_stream(int): Assertion `prevflags != -1' failed.
Error: signal 6:
2024-07-16 09:17:28 MySQL_Thread.cpp:2854:create_new_session_and_client_data_stream(): [ERROR] For FD -1 fcntl() returned -1 errno 9
 ---- /usr/bin/proxysql(_Z13crash_handleri+0x40) [0x55e7d41d3ae0] : crash_handler(int)
 ---- /usr/bin/proxysql(_ZN12MySQL_Thread41create_new_session_and_client_data_streamEi+0x459) [0x55e7d422f349] : MySQL_Thread::create_new_session_and_client_data_stream(int)
 ---- /usr/bin/proxysql(_Z11child_mysqlPv+0x136) [0x55e7d427e656] : child_mysql(void*)
To report a crashing bug visit: https://github.com/sysown/proxysql/issues
For support visit: https://proxysql.com/services/support/
2024-07-16 09:17:28 MySQL_Thread.cpp:2854:create_new_session_and_client_data_stream(): [ERROR] For FD -1 fcntl() returned -1 errno 9
proxysql: MySQL_Thread.cpp:2856: MySQL_Session* MySQL_Thread::create_new_session_and_client_data_stream(int): Assertion `prevflags != -1' failed.

```

(I have not yer opened an issue, just becouse it warns it’s for _reproducible_ bugs…, but I guess I should)

I realized that we had 4 of these crashes in a month.  
What can be the cause, how can I further debug?

I’m using proxysql 2.5.1-1

---

<div class="post-metadata">

**Author:** ![przemek](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/przemek/32/3_2.png) [@przemek](https://forums.percona.com/u/przemek)\
**Post date:** [July 17, 2024, 2:48pm UTC](https://forums.percona.com/t/crash-restart-of-proxysql-instances/31639/2 "2024-07-17T14:48:48Z")

</div>

Hi Alessandro\_Dentella,  
Looks like you are affected by [Proxysql 2.5 and ssl to mysql server never close fd on authority file. · Issue #4272 · sysown/proxysql · GitHub](https://github.com/sysown/proxysql/issues/4272) which was fixed in v2.5.5