Subject Re: [firebird-support] Firebird using all available memory
Author Fabiano Bonin
Hi, Omacht!

Indeed, it needs a sweep.

There a scheduled script that runs every night to sweep the database, and it broke with FB3 upgrade.

I fixed the script and it will run this night.

But, do you think the memory exaustion can be related to this issue?



2018-05-24 2:47 GMT-03:00 Omacht András aomacht@... [firebird-support] <>:

Hi Fabiano!

You should run garbage collection (sweep).

Oldest transaction 905
Oldest active 62303005
Oldest snapshot 62303005
Next transaction 62382577

fejlesztési igazgató

[cid:image001.png@01CFE703. C881C660]
Libra Szoftver Zrt.
1113 Budapest, Karolina út 65.
Tel.: +36 1 255 3939
Fax: +36 1 209 1477<ht tp://>

From: firebird-support@yahoogroups. com [mailto:firebird-support@]
Sent: Wednesday, May 23, 2018 4:29 PM
To: firebird-support@yahoogroups. com
Subject: Re: [firebird-support] Firebird using all available memory

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

[A képet a feladó eltávolította.]

2018-05-22 18:30 GMT-03:00 'Thomas Kragh-Pedersen (TKG)' TKG@...<mailto:TKG@...> [firebird-support] <firebird-support@yahoogroups. com<mailto: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<mailto:firebird-support@> <firebird-support@yahoogroups. com<mailto:firebird-support@>>
Sent: 18. maj 2018 16:12
To: firebird-support@yahoogroups. com<mailto:firebird-support@>
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.



Vi gør opmærksom på, at denne e-mail kan indeholde fortrolig information. Hvis du ved en fejltagelse modtager e-mailen, beder vi dig venligst informere afsender om fejlen ved at bruge svarfunktionen. Samtidig beder vi dig slette e-mailen i dit system uden at videresende eller kopiere den. Selvom e-mailen og ethvert vedhæftet bilag efter vores overbevisning er fri for virus og andre fejl, som kan påvirke computeren eller it-systemet, hvori den modtages og læses, åbnes den på modtagerens eget ansvar. Vi påtager os ikke noget ansvar for tab og skade, som er opstået i forbindelse med at modtage og bruge e-mailen.

Please note that this message may contain confidential information. If you have received this message by mistake, please inform the sender of the mistake by sending a reply, then delete the message from your system without making, distributing or retaining any copies of it. Although we believe that the message and any attachments are free from viruses and other errors that might affect the computer or it-system where it is received and read, the recipient opens the message at his or her own risk. We assume no responsibility for any loss or damage arising from the receipt or use of this message..

__________ Information from ESET Mail Security, version of virus signature database 17432 (20180523) __________

The message was checked by ESET Mail Security.

[Non-text portions of this message have been removed]