a lot of oninit process still running 1

[lgreyes]

Hi everybody,

I am new on Informix, I am try to understand some things,
first, I have two processors and four instances on my server, I can check that there are 33 oninit process, I read that the process oninit starts the dbserver, but why there are a lot of this process.

The second is how can I configure that Infomix work with 2 processors, at this time just one is working at 100 and How the parameters MULTIPROCESSORS, NUMAIOVPS, NUMCPUVPS are related.

Thanks.
Luis

 

[vpshriyan]

Hi,

Welcome to the world of Informix databases!

An instance, consists of set of Virtual process (VPs), shared memory and disk components configured to accept and serve the user requests. Such a collection of components is called a database server instance. This type of internal architecture helps the database server engine to accomplish the objectives of achieving higher degree of scalability.

The environment variable $INFORMIXSERVER points to an active instance. Such an instance has it's own $ONCONFIG file, a separate information line in sqlhosts file and other associated configuration files.

When multiple database server instances and their associated shared memory and disk structures co-exist on a single server machine, it is called multiple residency.

To see how many virtual processes work for given an instance use:
onstat -g sch
onstat -g glo

Usually, an instance owns one each of virtual processes in the Administration (ADM), Logical I/O (LIO), Physical I/O (PIO), and miscellaneous (MSC) classes. However for CPU and K/AIO the number of processes may vary according to the config parameters, like:

onstat -c | egrep "NUMAIOVPS|NUMCPUVPS"

You say, you have 4 active instances of database server in your box. These may be treated as too many, if you in a production environment and if you have lesser amount of resources, specially real memory.

You say that you have two processors in your box, and "just one is working at 100". Did you have disabled the other processor at Operating System level? Is your box is using Unix? In HP-UX you can use "top" to see the CPU states. In SCO-Unix you may use "mpstat" to see the cpu states I suppose. For multi-processor enabled boxes you can have:

MULTIPROCESSOR 1 # 0 for single-processor, 1 for multi-processor)
NUMCPUVPS 2 # Equal to number physical processors

NUMAIOVPS does not directly co-relate with multi-processor related parameters. It is related to the disk I/O activities and one follow the instructions outlined below:

Start with a number that is equal to the number of dbspaces that you have in your instance and steadily increase the number and benchmark the performance. Theoretically, one can go up to the number of chunks that one have in a database instance.

Regards,
Shriyan
"A good idea that is shared with others will live forever."

 

[lgreyes]

Thanks Shriyan.