| Bug #96919 | Performance drops with different workload and concurrency of sysbench | ||
|---|---|---|---|
| Submitted: | 18 Sep 2019 7:15 | Modified: | 24 Oct 2019 6:31 |
| Reporter: | zhai weixiang (OCA) | Email Updates: | |
| Status: | No Feedback | Impact on me: | |
| Category: | MySQL Server | Severity: | S5 (Performance) |
| Version: | 8.0.17 | OS: | Any |
| Assigned to: | CPU Architecture: | Any | |
[18 Sep 2019 7:16]
zhai weixiang
correct the title
[18 Sep 2019 13:30]
zhai weixiang
correct title
[18 Sep 2019 14:46]
zhai weixiang
Possiblely an issue of glibc...Firstly running with fresh restart, the point select performs very well. but when encountering regression, I can see hot __lll_lock_wait_private by malloc(). and _spin_lock from perf is almost 50% cpu time.
[24 Sep 2019 6:31]
MySQL Verification Team
Hello Zhai, Thank you for the report and feedback. May I request you to please provide configuration details used for these tests from your environment? Please mark it as private if you prefer after posting here. Thank you. regards, Umesh
[25 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".
Description: If running sysbench with different workload, repeat same oltp-point-select may see regression. For example, after a clean shutdown: oltp-point-select: 256 threads transactions: 4684752 (78039.86 per sec.) queries: 46847520 (780398.64 per sec.) oltp-read-write: 512 threads transactions: 339946 (5649.53 per sec.) queries: 6798920 (112990.63 per sec.) sleep 60 oltp-point-select: 256 threads transactions: 3777655 (62934.01 per sec.) queries: 37776550 (629340.13 per sec.) If running with same concurrency (for example, 256), there's no regression How to repeat: run sysbench src/sysbench oltp_point_select --mysql-host=$2--mysql-port=$1 --mysql-user='xx' --mysql-db=sb1 --tables=100 --table_size=25000 --threads=256 --max-time=60 --report_interval=5 run src/sysbench oltp_read_write --mysql-host=$2 --mysql-port=$1 --mysql-user='xx' --mysql-db=sb1 --tables=100 --table_size=25000 --threads=512 --max-time=60 --report_interval=5 run sleep 60 src/sysbench oltp_point_select --mysql-host=$2 --mysql-port=$1 --mysql-user='xx' --mysql-db=sb1 --tables=100 --table_size=25000 --threads=256 --max-time=60 --report_interval=5 run buffer pool: 128GB, 64 cores Suggested fix: Still investigate the issue