pajama

A need exist to add a new connection to the instance dynamically without any down time.

Starting with Informix version 11.50.xC6 we have the ability to Dynamically Start, Stop and Restart Listen threads with the onmode -P command or by using the SQL Admin API. 

This feature allows a new listener thread to be started on a port without the need to restart the database server. Adding new entries in to the sqlhosts file and the DBSERVERALIAS parameter of the onconfig file and executing the onmode -P or SQL API commands will allow new connections to utilize the new server name.

Steps:

1. Modify the sqlhosts to add the new connection:

      new_test_tcp onsoctcp myhost 4567 

2. Modify the DBSERVERALIAS parameter of the onconfig file: 

      DBSERVERALIASES main_prim_shm:new_test_tcp 

3. Start a listener thread for the new alias:

       onmode -P start new_test_tcp

OR use the sysadmin SQL API :

      execute function admin("start listen","new_test_tcp");

Changing the DB2 server's hostname.

Perform the following on the DB2 server:

1) Login as the dasadm user on UNIX/Linux or Local Administrator on Windows. Stop the DB2 Administration Server (DAS):

db2admin stop

db2stop

• UNIX/Linux
  db2iset -g DB2SYSTEM=<new hostname> 
  
• Windows 
  db2set -g DB2SYSTEM=<new hostname>

• UNIX/Linux:
  <db2 instance home directory>/sqllib/db2nodes.cfg
  
  
• All Windows flavors running DB2 v8 and v9.1: 
  Program Files\IBM\SQLLIB\DB2\db2nodes.cfg 
  
  
• Windows XP and 2003 running DB2 v9.5: 
  Documents and Settings\All Users\Application Data\IBM\DB2\<DB2COPY>\DB2\db2nodes.cfg
  
  NOTE: Application Data is a hidden folder
  
  
• Windows Vista and later operating systems: ProgramData\IBM\DB2\<DB2COPY>\DB2\db2nodes.cfg
  

db2 list admin node directory show detail 

If there are no Admin Node Directory entries then you can skip the next 2 steps. It simply means that you haven't started the Control Center. The Admin Node Directory will get updated the next time the Control Center is started, based upon the current hostname. 

db2 uncatalog node <nodename> 

db2 catalog admin tcpip node <nodename> remote <new hostname> system <new hostname> 

<nodename> can be anything you want it to be (8 characters or less). It does not relate directly to the hostname itself.

db2 update admin cfg using DB2SYSTEM <new hostname> 
db2 update admin cfg using SMTP_SERVER <new hostname>

db2admin start

db2start

• Only member of IXDBSA group (Informix-Admin, by default) can start IBM Informix Dynamic Server.
  
• Dynamic Server failed to start in Recovery Mode. Check Event Log for errors.
  
• System error 5 has occurred. Access is denied.

• Windows User Account Controls (UAC) component is enabled
  
• Lack of rights for user informix
  
• The user is not part of the IXDBSA group (Informix-Admin, by default)

• Always open your command windows with the "Run As Administrator" functionality.
  
• Disable the UAC component:
  
  http://technet.microsoft.com/en-us/library/cc709691(WS.10).aspx
  
• Add the needed user rights to user informix. Download the addrights utility from this site, read about it, run it, then logout and login to refresh user privileges:
  
  http://www.iiug.org/software/index_all.html#ntutils
  http://www.iiug.org/software/archive/ntutils.readme.txt
  
  EXAMPLE:
  
  C:\tmp\ntutils>addrights informix
  
• Add the user to the IXDBSA group (Informix-Admin, by default).

Check your system for a file named olsrvice.log (not olservice.log). You may find the file in the Informix server directory, C:\WINDOWS\system32, or possibly another directory. If the file contains the message that follows, then the server was not brought offline by terminating the database server service.

<timestamp>  Service was shut-down externally.

You should be able to mimic this behavior by executing a taskkill command to kill oninit.exe:

>taskkill /F /IM oninit.exe /T

DB2 Enterprise Server Edition v9.5 and higher is only supported in Test and Development mode on 32-bit Linux systems.

A DB2 Enterprise Server Edition permanent license may only be applied on a 64-bit Linux system.

Here are your options: 

• Upgrade the OS to 64-bit Linux and then install Enterprise Server Edition and license.
  
• Purchase another DB2 edition such as DB2 Workgroup Server Edition or DB2 Express Edition. You will need to also obtain and apply the corresponding permanent license.
  
• Purchase DB2 Developer's Edition for 32-bit Linux. The Developer's Edition license certificate (db2dede.lic) can be applied on top of a Enterprise Server Edition install without any problems.

This document explains how to count the number of processors on your system as IBM Informix® products defines a processor. Various IBM Informix® products are tuned based on the number of processors on your system. The NUMCPUVPS or VPCLASS onCONFIG configuration parameter, for example, should be set to one less than the actual number of physical CPUs present in the server. 

A processor is a device that operates on core. With multiple core technology, this can be a single device or a device that has multiple core "processors". IBM Informix® products consider these multiple cores as separate physical processors. 

On any HP-UX system, the ioscan command lists how many processors(single or multiple core) are on your system. The ioscan command (located in/usr/sbin) outputs a list of all IO devices. Each line in the output that begins with processor represents a processor that is either a single device or an instance of a multiple core device. 

Use the following command line to include the processors in the output and automatically count them using grep (pattern match) and wc (character count). For more information see your Operating System man pages.

/usr/sbin/ioscan -kf | grep processor | wc -l

Example 1: 

This example is from a machine with 2 processors. 


$   /usr/sbin/ioscan -kf|grep processor|wc -l 
2 

Note: You would set the NUMCPUVPS or VPCLASS parameter to 1 in this example. 

Example 2: 

This example is from a machine with 4 processors. 

$   /usr/sbin/ioscan -kf|grep processor|wc -l 
4

This example is from a machine with 4 processors. The Line count (wc -l) is left off to show the actual ioscan and grep output. 


$   /usr/sbin/ioscan -kf|grep processor 
processor   0  120            processor  CLAIMED     PROCESSOR    Processor 
processor   1  121            processor  CLAIMED     PROCESSOR    Processor 
processor   2  122            processor  CLAIMED     PROCESSOR    Processor 
processor   3  123            processor  CLAIMED     PROCESSOR    Processor 

Note: You would set the NUMCPUVPS or VPCLASS parameter to 3 in this example.

On AIX you use the command lsdev to determine how many CPUs your system has. The command lsdev (located in /usr/sbin) is used to list the system devices. Use it with the following options to list all processors one per line:

/usr/sbin/lsdev -C -c processor

Example: 

This example is from a single processor system. 


$ lsdev -C -c processor 
proc0 Available 00-00 Processor

When KAIOON environment variable is set to 1 to enable Kernel Asynchronous I/O (KAIO) on Informix Dynamic Server (IDS), the following error message is reported by IBM Informix Dynamic Server commands, such as onstat or oninit:

$onstat -
exec(): 0509-036 Cannot load program onstat because of the following errors:

0509-130 Symbol resolution failed for usr/lib/libc.a(aio.o)because:
0509-136   Symbol kaio_rdwr (number 0) is not exported from dependent module /unix.
0509-136   Symbol listio (number 1) is not exported from dependent module /unix.
0509-136   Symbol acancel (number 2) is not exported from dependent module /unix.
0509-136   Symbol iosuspend (number 3)is not exported from dependent module /unix.
0509-136   Symbol aio_nwait (number 4) is not exported from dependent module /unix.
0509-192 Examine .loader section symbols with the'dump -Tv' command.    

The IBM Informix Dynamic Server requires that the drivers for Asynchronous IO (AIO) be loaded on the AIX system where the IBM Informix Dynamic Server is used. The IBM Informix Dynamic Server executables use entry points defined by these drivers.

The error can be seen when AIO was not enabled at the AIX system.