Automatic Informix instance discovery and set up

After you install infx, you run the discovery service to locate existing Informix instances. This automatically configures infx to access and manage them.

The infx disco command locates instances in the output of onstat -g dis, reads their ONCONFIG files, and creates the required files and directories.

This all happens automatically in the background, the purpose of this post is to go through each of those steps in more detail.

Step 1. Locate instances

The infx disco command uses the output from onstat -g dis to locate existing instances.

Sample output:

There are 1 servers found
Server        : ol_informix1170
Server Number : 116
Server Type   : IDS
Server Status : Down
Server Version: IBM Informix Dynamic Server Version 11.70.FC4IE
Shared Memory : 0x44000000
INFORMIXDIR   : /home/informix/sw/IIF_11.70FC4IE
ONCONFIG      : /home/informix/sw/IIF_11.70FC4IE/etc/onconfig.ol_informix1170
SQLHOSTS      : /home/informix/sw/IIF_11.70FC4IE/etc/sqlhosts.ol_informix1170
Host          : bobii

Step 2. Set up instance variables

infx uses the following information to connect to the instance:

variable	setting
INFORMIXSERVER	ol_informix1170
INFORMIXDIR	/home/informix/sw/IIF_11.70FC4IE
ONCONFIG	onconfig.ol_informix1170
INFORMIXSQLHOSTS	/home/informix/sw/IIF_11.70FC4IE/etc/sqlhosts.ol_informix1170

Step 3. Set up infx variables

infx calculates other values it needs, by reading the ONCONFIG file:

infx var	variable	value	location
CHKDIR	ROOTPATH	directory portion of path	/infx/inst/ol_informix1170/etc/config.ini
instalias	DBSERVERALIAS	alternate instance names	/infx/local/etc/config.ini

Step 4. Set up directories

infx requires a few directories for each instance. These are for config information, log files and temp files:

directory	reason
/infx/inst/ol_informix1170	top level directory
/infx/inst/ol_informix1170/etc	instance specific config files
/infx/inst/ol_informix1170/tmp	infx services temp files
/infx/inst/ol_informix1170/logs	infx services log files

Once set up is complete, and you can start executing infx commands on this instance e.g.

demo1b@bobii:/home/informix>infx list

bobii(192.168.0.34) cpus: 2/2 mem: 3.89gb free: 0.03gb time: Sun Mar 18 11:48:16 2012

stat inst            mode   version      up           mem    read   write  informixdir
..   ...             ...    ...          ...          ...     ...     ...  ...
ok   ol_informix1170 online 11.70.FC4IE  00:00:20  0.17gb  93.85%  96.53%  IIF_11.70FC4IE
...    ...           ...    ...          ...          ...     ...     ...  ...

infx disco options

By default, the infx disco command only lists instances and does not automatically set up anything. You must specify additional options to set up any instances.

command	function
infx disco	list new instances
infx disco newinst=ol_informix1170 save=yes	set up new instance called ol_informix1170
infx disco newinst=all save=yes	set up all new instances

infx auto service

The infx auto service is used to automatically execute a command against every instance on a host. For example, this service is used to start and stop the instances at boot time, and to execute automatic backups.

By default, infx creates four files for each new instance. These files prevent the automatic service from executing against the new instance.

When you are ready for infx to include the new instances, remove these files from /infx/inst/ol_informix1170/etc

file	purpose
deny-auto-backup-dbs	do not include in automatic backups
deny-auto-clean	do not automatically clean storage pools
deny-auto-start	do not automatically start instance at system boot time
deny-auto-stop	do not automatically stop instance at system shutdown time

For more information about installing and configuring infx, see www.infx.me/1-install