Hi,
I have a Windows server that has been running MariaDB
10.1 successfully for over a year. The server remains
mostly idle for long times with some read access, but
occasionally there are transactions that add data
(about 500k rows per commit). There can be up to 10
such transactions (one per database) at the same time
and during those times the server is under quite some
load (the code processing the data resides on the same
server as the database). We're using an 8 core AMD
Ryzen, 32 GB RAM and a Samsung SSD.
Like I said, this worked fine with MariaDB 10.1 all
the time.
We're currently in the process of setting up a new
server (specs similar to the ones above) and because
MariaDB 10.3 has been released recently, I was curious
and installed it. The database now constantly shuts
down because of "[FATAL] InnoDB: Semaphore wait has
lasted > 600 seconds. We intentionally crash the
server because it appears to be hung." whenever there
is one of the load situations described above. If I
install MariaDB 10.1 on the new server, it runs as
fine as the old one. The crashes also happen when I
start with a clean database (no data migrated from
10.1 databases).
I'm not a huge MariaDB config pro, as it's only a
tool to store the data, it just needs to run with
reasonable performance and has always worked until
now. As far as I know and can judge from comments in
the file, the my.ini in use is (mostly?) based on
my-innodb-heavy-4G.cnf, but coworkers might have made
modifications. I've attached the contents below.
I don't know how I can debug this issue further.
Windows event viewer contains several log warnings
with the text "InnoDB: A long semaphore wait:" but no
further information why this wait happens. I couldn't
find any other error logs. I guess it is some
configuration error (I read about MariaDB switching
from XtraDB to InnoDB, so I guess that the issue might
be related).
Migrating to 10.3 is not an absolute must, but it
would be nice to be able to fix the problem.
Any help would be greatly appreciated and if you need
more information, I'll gladly try to provide it.
Thanks,
Tom.
my.ini:
[mysqld]
max_connections
= 100
max_allowed_packet
= 16M
binlog_cache_size
= 1M
max_heap_table_size
= 64M
read_buffer_size
= 2M
read_rnd_buffer_size
= 16M
sort_buffer_size
= 8M
join_buffer_size
= 8M
thread_cache_size
= 10
query_cache_size
= 64M
query_cache_limit
= 2M
thread_stack
= 240K
tmp_table_size
= 64M
slow_query_log
expire_logs_days = 14
log-bin = mysql-bin
character-set-server=utf8
collation-server=utf8_general_ci
#***
MyISAM Specific options
key_buffer_size
= 32M
bulk_insert_buffer_size
= 64M
myisam_sort_buffer_size
= 128M
myisam_max_sort_file_size
= 10G
myisam_repair_threads
= 1
myisam_recover
#
*** INNODB Specific options ***
#innodb_fatal_semaphore_wait_threshold
= 6000 #tried that, didn't help
#innodb_adaptive_hash_index
= 0 #tried that (suggested in some stack overflow
post, didn't help)
innodb_buffer_pool_size
= 2G
innodb_data_file_path
= ibdata1:10M:autoextend
innodb_write_io_threads
= 8
innodb_read_io_threads
= 8
innodb_thread_concurrency
= 16
innodb_log_buffer_size
= 8M
innodb_log_file_size
= 256M
innodb_log_files_in_group
= 3
innodb_max_dirty_pages_pct
= 10
innodb_io_capacity
= 2000
innodb_lock_wait_timeout
= 120
[mysql]
no-auto-rehash
[myisamchk]
key_buffer_size
= 512M
sort_buffer_size
= 512M
read_buffer
= 8M
write_buffer
= 8M
[mysqld_safe]
open-files-limit
= 8192