Virtual processor classes

Each class of virtual processor is dedicated to processing certain types of threads.

The following table shows the classes of virtual processors and the types of processing that they do.

The number of virtual processors of each class that you configure depends on the availability of physical processors (CPUs), hardware memory, and the database applications in use.
Table 1. Virtual-processor classes
Virtual- processor class Category Purpose
ADM Administrative Performs administrative functions.
ADT Auditing Performs auditing functions.
AIO Disk I/O Performs nonlogging disk I/O. If KAIO is used, AIO virtual processors perform I/O to cooked disk spaces.
BTS Basic text searching Runs basic text search index operations and queries.
CPU Central processing Runs all session threads and some system threads. Runs thread for kernel asynchronous I/O (KAIO) where available. Can run a single poll thread, depending on configuration.
CSM Communications Support Module Performs communications support service operations.
dwavp Data warehousing Runs the administrative functions and procedures for Informix® Warehouse Accelerator on a database server that is connected to Informix Warehouse Accelerator.
Encrypt Encryption Used by the database server when encryption or decryption functions are called.

On Windows systems, the number of encrypt virtual processors is always set to 1, regardless of the value that is set in the onconfig file.

IDSXMLVP XML publishing Runs XML publishing functions.
JVP Java™ UDR Runs Java UDRs. Contains the Java Virtual Machine (JVM).
LIO Disk I/O Writes to the logical-log files (internal class) if they are in cooked disk space.
MQ MQ messaging Performs MQ messaging transactions.
MSC Miscellaneous Services requests for system calls that require a very large stack.
PIO Disk I/O Writes to the physical-log file (internal class) if it is in cooked disk space.
SHM Network Performs shared memory communication.
SOC Network Uses sockets to perform network communication.
tenant Multitenancy Runs session threads for tenant databases. Tenant virtual processors are a special case of user-defined processors that are specific to tenant databases.
TLI Network Uses the Transport Layer Interface (TLI) to perform network communication.
WFSVP Web feature service Runs web feature service routines.
classname User defined Runs user-defined routines in a thread-safe manner so that if the routine fails, the database server is unaffected.
The following figure illustrates the major components and the extensibility of the database server.
Figure 1. Database server
This figure shows seven client applications, threads running from virtual processors, and DataBlade modules that extend the database server. See the surrounding text for more information about threads and virtual processors.

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