| Bug #105612 | Server hangs - Flags for USE_PPOLL_IN_VIO not propagated when client uses SSL | ||
|---|---|---|---|
| Submitted: | 17 Nov 2021 11:35 | Modified: | 17 Nov 2021 11:54 |
| Reporter: | Kamil Holubicki (OCA) | Email Updates: | |
| Status: | Verified | Impact on me: | |
| Category: | MySQL Server: Connection Handling | Severity: | S3 (Non-critical) |
| Version: | 8.0.27, 5.7.36 | OS: | Any |
| Assigned to: | CPU Architecture: | Any | |
| Tags: | Contribution | ||
[17 Nov 2021 11:36]
Kamil Holubicki
proposed fix (*) I confirm the code being submitted is offered under the terms of the OCA, and that I am authorized to contribute it.
Contribution: use_ppoll_in_vio.patch (text/x-patch), 552 bytes.
[17 Nov 2021 11:38]
Kamil Holubicki
Note: Forcefully disconnecting 0 remaining clients in the original description should be: Forcefully disconnecting 1 remaining clients
[17 Nov 2021 11:54]
MySQL Verification Team
Hello Kamil Holubicki , Thank you for the report and feedback. Verified as described with 8.0.27 build. regards, Umesh
[17 Nov 2021 11:58]
MySQL Verification Team
-- 8.0.27
./mysql-test/mtr --parallel=50 mysql_client_test{,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,}
-bash: ./mysql-test/mtr: No such file or directory
[umshastr@support-cluster03:/export/home/tmp/ushastry/mysql-8.0.27/mysql-test]$ ./mtr --parallel=50 mysql_client_test{,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,}
Logging: ./mtr --parallel=50 mysql_client_test mysql_client_test mysql_client_test mysql_client_test mysql_client_test mysql_client_test mysql_client_test mysql_client_test mysql_client_test mysql_client_test mysql_client_test mysql_client_test mysql_client_test mysql_client_test mysql_client_test mysql_client_test mysql_client_test mysql_client_test mysql_client_test mysql_client_test mysql_client_test mysql_client_test mysql_client_test mysql_client_test mysql_client_test mysql_client_test mysql_client_test mysql_client_test mysql_client_test mysql_client_test mysql_client_test mysql_client_test
MySQL Version 8.0.27
Checking supported features
Using 'all' suites
Collecting tests
Checking leftover processes
Removing old var directory
Creating var directory '/export/home/tmp/ushastry/mysql-8.0.27/mysql-test/var'
Installing system database
Using parallel: 32
==============================================================================
TEST NAME WORKER RESULT TIME (ms) COMMENT
------------------------------------------------------------------------------
[ 3%] main.mysql_client_test w24 [ pass ] 63949
[ 6%] main.mysql_client_test w20 [ pass ] 65492
[ 9%] main.mysql_client_test w4 [ pass ] 65828
.
.
##
find ./var/ -type f -exec grep -H 'Forcefully disconnecting 1 remaining clients' {} \;
./var/5/log/mysqld.1.err:2021-11-17T11:53:52.330646Z 0 [Note] [MY-010118] [Server] Forcefully disconnecting 1 remaining clients
./var/23/log/mysqld.1.err:2021-11-17T11:53:52.465721Z 0 [Note] [MY-010118] [Server] Forcefully disconnecting 1 remaining clients
[26 Jan 2022 8:43]
Frederic Descamps
This contribution has been processed by our development team and has been accepted. It will be included into a future release. Thank you again.
Description: This issue is hard to reproduce, and I don't have a reliable way to do it. How to repeat: I was able to trigger it with long, parallel execution of mysql_client_test MTR test: ./mysql-test/mtr --parallel=12 mysql_client_test{,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,} but it is rare. It looks like it occurs randomly, and the common denominator is having the following log in the error file: Forcefully disconnecting 0 remaining clients So the mechanism is that we have opened the client's SSL connection and we are shutting down the server from yet another client session. Suggested fix: Code analysis leads to the conclusion that there is missing propagation of thread_id, signal_mask and poll_shutdown_flag in vio.cc::vio_reset() which is called during SSL handshake. These flags are used for shutting down the client's connection socket. Please see the attached patch for the fix proposal.