What is difference between external database and embedded database when I want to use mysql ?
Is it have a constrain about size of memory or anything ?
If I use app-serv, can I also use openfire server ?
As you can see in the following document:
http://www.igniterealtime.org/builds/openfire/docs/latest/documentation/database .html
Openfire uses HSQLDB as its embedded database. And any other databases are considered external.
I would not be able to advise on Openfire operating on the same box as AppServ, but I can’t see why it should not work. Just be careful if you decide to remove AppServ as it may remove MySQL as well.
The embedded database is held in memory. So when you have a large user base or chat logging enabled the database will not be small. Openfire also uses a database cache, so things are held in memory two times. As long as you have less than 100 users and you don’t want to install plugins which do chat logging then the internal database is usually fine. http://hsqldb.org/ is the home page of the internal database, as far as I can tell it is a good database.
LG