Tested on Raspberry Pi with Raspbian

Zabbix does not support in memory destination. It is not implemented.

If that is true, can we add that to the documentation until it is? I would like to help contribute to the zabbix documentation, if I can.

Kenny,

DBName=:memory: is non multi processes database. it is only per one process. Have you tried to specify DBName=file:memdb1?mode=memory&cache=shared?

No, I haven't tried that. I will try now.

5438:20171206:055509.346 cannot open database file "file:memdb1?mode=memory&cache=shared": [2] No such file or directory
5438:20171206:055509.346 creating database ...
5438:20171206:055509.364 [Z3002] cannot create database 'file:memdb1?mode=memory&cache=shared': [0] unable to open database file

The problem with :memory: is that database ceases to exist when connection is closed and Zabbix main process does exactly that after importing schema. If you pass file::memory:?cache=shared as DBName created database will outlive the connection. There is no real need in file:memdb1?mode=memory&cache=shared because Zabbix does not need multiple distinguishable databases. But, and this is a huge "but":

all database connections sharing the in-memory database need to be in the same process

which is not applicable to Zabbix at the moment. To my understanding after forking each forked process will have a completely independent database. However, there is a very limited use case when this setup may be functioning — passive proxy with StartTrappers=1 monitoring only trapper items and active agents. Not sure that you will gain any performance from it.

Ok, tmpfs it is! Thanks for your help, and your ability to help me understand the issue!

Thank you! It was an interesting issue to investigate. Let's document it!

Necessary documentation update has been executed in cooperation with glebs.ivanovskis for all supported versions (Zabbix proxy parameter table) DBName parameter description update.

Dear glebs.ivanovskis , please review and close if it's ok.

RESOLVED

glebs.ivanovskis Technically, in 3.0 SQLite can be used as server's database too. Should we update server's config parameters? Or shall we remove SQLite mention from there as not recommended?

natalja.cernohajeva: fixed for 3.0 Zabbix server parameters. Please review.
RESOLVED

glebs.ivanovskis Good.
CLOSED

Hi!
Just for the record, I was having problem on a very old Raspberry PI 1. Writing to the Sqlite3 DB was not fast enough.

So I used tmpfs to store the DB:

$ grep tmpfs /etc/fstab
tmpfs   /var/lib/sqlite-ram/	tmpfs   rw,nodev,nosuid,uid=zabbix,gid=zabbix,size=50M          0  0

$ grep DBName /etc/zabbix/zabbix_proxy.conf | grep -v ^#
DBName=/var/lib/sqlite-ram/zabbix.db

Et voilà, the proxy is now working and perfectly sufficient for this particular setup (monitoring himself + a bunch of ping on wireless AP).
Cheers

My contribution:

DBName=/run/zabbix/zabbix_proxy.db