[ejabberd] ejabberd stress testing

Mickaël Rémond mickael.remond at erlang-fr.org
Sun Aug 28 01:43:58 MSD 2005

Le 26 août 05 à 22:13, Matthew Reilly a écrit :

> I'm stress testing ejabberd with jab_simul.
> I discovered that sometimes while having many
> login attempts, and always when having many
> simultaenous log offs, I received mnesia errors:
> ** Too many db tables **
> I've been able to avoid this by adding
> -env ERL_MAX_ETS_TABLES 20000
> I believe that this is due to too many mnesia
> transactions.

That's right. A database transaction implies the creation of an ETS  

> Q1) I've not found much info about ets/ERL_MAX_ETS_TABLES
> online. Does anyone know if what there are
> any drawbacks/penalties to increasing this value?

You can safely increase this limit. It impacts memory consumption but  
the difference will be quite small.

> Q2) ERL_MAX_ETS_TABLES is not listed in:
> http://ejabberd.jabber.ru/tuning
> should info about ERL_MAX_ETS_TABLES be added?

I will increase this default value in the Linux installer as well.

I hope this helps,

Mickaël Rémond

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