performance regression in mariadb-5.3 with many threads
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
MariaDB |
Fix Released
|
High
|
Oleksandr "Sanja" Byelkin |
Bug Description
sysbench OLTP benchmark with 64 threads yields 50% or fewer operations per second with MariaDB 5.3.3-rc compared to MariaDB 5.2.10.
I.e. on a machine with 24 cores we get 125K ops/sec with 5.2.10 but only 64K ops/sec with 5.3.3. With more cores the result gets worse. I.e. 32 cores give 175K vs. 39K.
sysbench parameters: --test=oltp --num-threads=64 --max-time=60 --max-requests=0 --oltp-
my.cnf:
skip-external-
bind-address = 127.0.0.1
key_buffer = 16M
max_allowed_packet = 16M
default-
innodb_
innodb_
innodb_
innodb_
innodb_
innodb_
innodb_
innodb_
innodb_
innodb_
innodb_
innodb_
back_log = 50
max_connections = 100
table_open_cache = 2048
max_heap_table_size = 64M
sort_buffer_size = 8M
join_buffer_size = 8M
thread_cache_size = 8
query_cache_size = 64M
query_cache_limit = 2M
thread_stack = 192K
transaction_
tmp_table_size = 64M
long_query_time = 2
PMP shows significant mutex contention in the Query_cache:
Changed in maria: | |
assignee: | nobody → Oleksandr "Sanja" Byelkin (sanja-byelkin) |
importance: | Undecided → High |
Changed in maria: | |
status: | New → Incomplete |
status: | Incomplete → In Progress |
milestone: | none → 5.3 |
Changed in maria: | |
status: | In Progress → Fix Committed |
Changed in maria: | |
status: | Fix Committed → Fix Released |