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