Hi MJ, > 5) verify from mariadb: > SHOW GLOBAL VARIABLES LIKE 'jemalloc%';
I think you mean: SHOW GLOBAL VARIABLES LIKE 'version_malloc_library'; Or alternatively: select @@version_malloc_library; Karl On Wed, 19 Mar 2025 at 14:18, sacawulu via discuss < [email protected]> wrote: > Hi, > > I've followed this thread with great interest. > > Just to confirm, if we also want to change to tmalloc, running on > RHEL8/9, a quick google tells me that the steps are: > > 1) sudo yum install gperftools-libs > > 2) rpm -ql gperftools-libs | grep tcmalloc > > (save the file/path) > > 3) edit the mariadb systemctl file: > > sudo systemctl edit mariadb > and add > [Service] > Environment="LD_PRELOAD=/usr/lib64/libtcmalloc_minimal.so.4" > > 4) restart mysql > > 5) verify from mariadb: > SHOW GLOBAL VARIABLES LIKE 'jemalloc%'; > > 6) optimize mariadb: > [mariadb] > malloc-lib=/usr/lib64/libtcmalloc_minimal.so.4 > > Or is there a simpler/more standard method? > > MJ > > On 3/17/25 15:48, Derick Turner via discuss wrote: > > System (default) made zero difference. TC Malloc, on the other hand, has > > been a winner! The server which I switched this to has sat on 15/16GB > > while the rest have continued to consume all of the memory. > > > > I'll switch over all of the servers to use this and I will put the other > > settings back to where they originally were. (30GB RAM server with 22GB > > innodb_buffer_pool) > > > > Thank you for you help with this. It is very much appreciated! > > > > Kind regards > > > > Derick > > > > On 17/03/2025 12:13, Derick Turner via discuss wrote: > >> Thanks for the response Sergie! > >> > >> I switched over to jemalloc in an effort to try and resolve the issue > >> - as I had seen some posts suggesting that as a potential option to > >> deal with memory leaks. I've removed this from one of the servers > >> which has set it back to system. On the next rotation of restarts I'll > >> change another to tmalloc, so I can track any differences between the > >> three. > >> > >> In case this is also related: we do not get any instances in the logs > >> for InnoDB: Memory pressure events. The listener is being started on > >> all instances. I'm assuming this is where the memory in the InnoDB > >> cache is being released back to the OS? There were logged instances > >> of this running when all of the memory was consumed and the system was > >> starting to use swap. However, OOM killer eventually kicked in and > >> killed the DB process, which is too much of a risk for us to have > >> happen at the moment. > >> > >> Kind regards > >> > >> Derick > >> > >> On 17/03/2025 11:55, Sergei Golubchik wrote: > >>> Hi, Derick, > >>> > >>> According to your SHOW GLOBAL STATUS > >>> > >>> Memory_used 15460922288 > >>> > >>> That is the server thinks it uses about 15GB > >>> > >>> The difference could be due to memory fragmentation, when the server > >>> frees the memory, but it cannot be returned to the OS. In this case > >>> using a different memory allocator could help (try system or tcmalloc). > >>> > >>> Regards, > >>> Sergei > >>> Chief Architect, MariaDB Server > >>> and [email protected] > >>> > >>> On Mar 17, Derick Turner via discuss wrote: > >>>> Hi all, > >>>> > >>>> I was pointed to this list from a question I raised on StackExchange > >>>> (https://dba.stackexchange.com/questions/345743/why-does-my-mariadb- > >>>> application-use-more-memory-than-configured) > >>>> > >>>> I have a cluster of MariaDB (11.4.5) primary/primary servers running > on > >>>> Ubuntu. I updated the OS on Saturday to 24.04 from 22.04 (and patched > >>>> the DB to the 11.4.5 noble version) as we were occasionally hitting an > >>>> OOM event which was causing the database process to be killed. Since > >>>> then, the DB process takes all of the available server memory before > >>>> being killed by the OOM killer. > >>>> > >>>> DB is configured to use about 15GB of RAM (from config calculations) > >>>> Servers currently have 50GB of RAM and 95% of this is used within > about > >>>> an hour an a half. > >>>> > >>>> Link to document with configuration settings, global status, > >>>> mariadb.service override and InnoDB status is here - > >>>> https://docs.google.com/spreadsheets/ > >>>> d/1ev9KRWP8l54FpRrhFeX4uxFhJnOlFkV4_vTCZWipcXA/edit?usp=sharing > >>>> > >>>> Any help would be gratefully received. > >>>> > >>>> Thanks in advance. > >>>> > >>>> Derick > >>>> > >>>> -- > >>>> Derick Turner - He/Him > >>>> > >>>> _______________________________________________ > >>>> discuss mailing list -- [email protected] > >>>> To unsubscribe send an email to [email protected] > >> > > _______________________________________________ > discuss mailing list -- [email protected] > To unsubscribe send an email to [email protected] >
_______________________________________________ discuss mailing list -- [email protected] To unsubscribe send an email to [email protected]
