Subject Re: [firebird-support] Firebird using all available memory
Author Javier Cintron

Do you have several Firebird installations(instances) in the same machine?
Perhaps firebird is reading a different firebird.conf. 

Why don't you post your complete firebird.conf?

On Wednesday, May 23, 2018, 9:29:30 AM CDT, Fabiano Bonin fabiano.bonin@... [firebird-support] <> wrote:


Hi, Thomas. It is zero. I presume in this case it uses the system default, right?



Database header page information:
        Flags                   0
        Generation              62390727
        System Change Number    0
        Page size               4096
        ODS version             12.0
        Oldest transaction      905
        Oldest active           62303005
        Oldest snapshot         62303005
        Next transaction        62382577
        Sequence number         0
        Next attachment ID      1290314
        Implementation          HW=AMD/Intel/x64 little-endian OS=Linux CC=gcc
        Shadow count            0
        Page buffers            0
        Next header page        0
        Database dialect        3
        Creation date           Apr 4, 2018 7:03:44
        Attributes              force write

2018-05-22 18:30 GMT-03:00 'Thomas Kragh-Pedersen (TKG)' TKG@... [firebird-support] <>:

Hey Fabiano

Perhaps DefaultDbCachePages is overwritten by database header information. Gstat -h will tell you that. Look for “Page buffers”



From: firebird-support@yahoogroups. com <firebird-support@yahoogroups. com>
Sent: 18. maj 2018 16:12
To: firebird-support@yahoogroups. com
Subject: [firebird-support] Firebird using all available memory





I have a Debian 9 Linux server with 8GB of memory, a database with 30GB, page size 4KB, and Firebird 3.0.3 running in superserver mode and about 150-200 concurrent connections.


In my firebird.conf I have changed the following properties:


DefaultDbCachePages = 524288 # 2GB

TempCacheLimit = 1024M # 1GB

LockMemSize = 2M


As superserver uses a shared cache, I presumed the total used memory should stay between 3GB and 4GB, but it keeps growing during the day until it reaches the 8GB limit and Firebird shuts down with this message:


debian  Fri May 18 10:45:35 2018
        Shutting down the server with 150 active connection(s) to 2 database(s), 0 active service(s)


I am checking the active transactions during the day, and altought there are some old (2h to 3h) active transactions, I don't that an old active transaction should cause this, but I am reporting anyway, maybe it is relevant.


Do someone have some advice to what should I do to prevent this from happening?


Maybe my understanding about how Firebird uses memory is incorrect, so any advice about how I should calculate the required amount of memory needed is welcome.


PS: I have migrated from FB 2.5 recently (previously I did use superclassic mode), and these problems started after the migration.





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