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Re: [Maria-discuss] MariaDB crashes because of "long semaphore wait"after migrating from 10.1 to 10.3


Thanks for the quick response, I opened a ticket (https://jira.mariadb.org/browse/MDEV-16467).

I cannot attach the core dump though as it contains sensitive information (I opened it in an editor and checked the strings). If absolutely neccessary, I can try to recreate the issue with test data, but this might be complicated. I've attached a full log from database startup up until the crash though.


Am 10.06.2018 um 22:38 schrieb Vladislav Vaintroub:

I think this is a bug, and as such it is best to have in JIRA https://jira.mariadb.org/  . it is not really to possibly to give a good advice on a vaguely defined bug without  extra info.

In that particular case,  I suggest to add core-file=1 to the my.ini, wait for a crash, and attach both error log  and core (which will be named mysqld.dmp and created in the data directory) to the bug report, and we’ll take it from there.

*From: *Vicențiu Ciorbaru <mailto:vicentiu@xxxxxxxxxxx>
*Sent: *Sunday, June 10, 2018 8:23 PM
*To: *TD <mailto:tdcf@xxxxxxx>
*Cc: *Maria Discuss <mailto:maria-discuss@xxxxxxxxxxxxxxxxxxx>; maria-developers <mailto:maria-developers@xxxxxxxxxxxxxxxxxxx>; Marko Mäkelä <mailto:marko.makela@xxxxxxxxxxx>; Vladislav Vaintroub <mailto:wlad@xxxxxxxxxxx> *Subject: *Re: [Maria-discuss] MariaDB crashes because of "long semaphore wait"after migrating from 10.1 to 10.3


I have cc'ed the maria-developers mailing list as this is potentially a dev issue and also the devs responsible for Windows and InnoDB development. There might be some people on vacation right now, but this should get looked into in a week or two at most.

Let's find a solution for your problem. :)


On Sun, 10 Jun 2018, 19:11 TD, <tdcf@xxxxxxx <mailto:tdcf@xxxxxxx>> wrote:


    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

    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.



    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
    expire_logs_days = 14
    log-bin = mysql-bin

    #*** 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

    # *** INNODB Specific options ***
    #innodb_fatal_semaphore_wait_threshold = 6000 #tried that, didn't
    #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


    key_buffer_size = 512M
    sort_buffer_size = 512M
    read_buffer = 8M
    write_buffer = 8M

    open-files-limit = 8192

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