Database Analyzer task

Tasks for Database Analyzer

Database Analyzer tasks are taken from the floating service task pool, which is limited by the FloatingServiceTasks parameter. More information: Support Parameter

Event task

Tasks for events

Event tasks are also taken from the floating service task pool, which is limited by the FloatingServiceTasks parameter.

Floating Service task

Database Analyzer and Event tasks are taken from the floating service task pool, which is limited by the FloatingServiceTasks parameter.

Idle task

Used for internal task scheduling

Log Writer

Log Writers write log entries from the log queue to the log area, for example after a COMMIT or during a savepoint.

There is a log writer for each log partition. More information: Log Area

You define the maximum number of log writers with the special database parameter MaxLogWriterTasks. More information: Special Database Parameters

Pager (formerly Data Writer)

Pagers write the data from the data cache to the data volumes at each savepoint. Writing a savepoint can take a long time for a large data cache. If necessary, Pagers also become active between savepoints, to write the changed data asynchronously.

During a restart of the database, Pagers read the converter pages from the data volumes into the converter.

The system calculates the number of Pagers required. It is primarily dependent on the size of the data cache and the number of data volumes.

Server task

Server tasks parallelize database functions. They are required, for example, to back up data and log entries, create indexes and to permanently delete tables. During a restart of the database, Server tasks import log entries and process transactions in parallel.

You can configure the number of Server tasks that are available using the MaxServerTasks special database parameter.

Server tasks can have special names that reflect how they are used, for example Savepoint, BackupMedium, BackupVolume, AutosaveCoordinator, AutosaveMedium.

Timer task

The Timer task is responsible for time-outs of SQL lock requests and checks whether log entries can be backed up.

Trace Writer task

The Trace Writer task writes the trace entries in the working memory when the database trace is switched on.

User task

User tasks execute SQL statements.

When a database user opens a database session, the database system assigns one User task to this database user.

User tasks create the main load for the processor.

You can configure the number of available User tasks using the special database parameter MaxUserTasks.

Utility task

The Utility task performs administration tasks.

AsynClose

Stream Close

Task is closing I/O ports after backup or restore.

AsynCntl

-

Task is determining parameters or initializing a backup device.

AsynIO

Stream IO

Task is executing I/O operation (during backup or restore).

-

Stream Init

Task is initializing backup or restore operation.

AsynOpen

Stream Open

Task is opening I/O ports for backup or restore.

AsynWaitRead/Write

Stream Wait(R)/(W)

Task is waiting for the end of an I/O operation during backup or restore (W: Write, R: Read).

Command reply

Command reply

Task is sending the result of a request to the application.

Command wait

Command wait

Database session without a request.

Connect wait

Connect wait

Task is already running and waiting for the database session to be created.

Continue

Continue

Tasks is in the process of releasing another task from the Stopped state.

DcomObjCalled

LCApp Called

Task is executing an SAP liveCache application routine.

Inactive

Inactive

Task is free (not linked) and cannot run. The task does not have a stack.

InsertEvent

Insert Event

Task is generating an event.

-

IO CPort Wait

Task is waiting for an RTE Completion Port.

-

IO Job Execute

Task is executing an I/O job.

-

IO Job Wait

Task is waiting for the end of an I/O job.

IO wait (W/R)

IO wait (W/R)

Task is waiting for the result of an I/O operation (W: Write, R: Read).

Locked

Locked

Task was locked as the kernel was shut down (to avoid this task being rescheduled).

Mark for Start

Startable

Task is free (not linked) and cannot run. The task already has a stack (system has already allocated all resources) and is waiting for the start.

RescheduleMsec

RescheduleMsec

Short-term wait situation, task will run again automatically after a predefined time span (in microseconds).

Runnable

ShareLck Yield

Task can run now, but has been displaced due to long runtime or priority of another task.

Runnable

ExclLock Yield

Task can run now, but has been displaced due to long runtime or priority of another task.

Running

Running

Task is running, using CPU.

Spinlock loop

Spinlock Loop

Task is trying to obtain a spinlock.

SpinlockYield

Spinlock Yield

Task gives up control voluntarily. This situation occurs when the task has just tried to obtain a spinlock but without success.

Stopped

Stopped

Task was stopped by the kernel and is waiting to run again.

Terminated

Terminated

Task or database session was ended.

UNKNOWN

UNKNOWN

Task state is unknown.

Vattach

Volume Attach

Task is opening I/O ports (volumes, normal operation).

Vbegexcl

Enter ExclLock

Task is waiting to be allowed to enter a protected area exclusively.

Vdetach

Volume Detach

Task is closing I/O ports (volumes).

Vdevsize

-

Task is determining the size of a volume or formatting a volume.

Vdualvectorio

Dual Vector IO

Task is performing a vector I/O operation (read or write) on two volumes in parallel.

vdiaginit

Trace init

Task is initializing the trace volume.

Vendexcl

Leave ExclLock

Task is leaving a protected area.

VenterRWRegion

Enter ShareLck

Task is waiting to be allowed to enter a conditionally shared area.

Vfclose

File Close

Task is closing a file.

Vfopen

File Open

Task is opening a file.

Vfwrite

File Write

Task is writing to a file.

VleaveRWRegion

Leave ShareLck

Task is exiting a protected, conditionally shared area.

-

VolumeFormatW

Task is waiting for a volume to be formatted.

Vopmsg

Message Output

Task is writing a message to one of the following database files: knldiag, knldiag.err, opmsg[n]

Vrelease

Connect Close

Task is ending the database session.

Vshutdown

DB OFFLINE

Task is changing the operational state of the database from ONLINE to OFFLINE.

Vsleep

Sleeping

Short-term wait situation, task will run again automatically after a predefined time span.

Vsuspend

Suspend

Task is suspended and waiting to be awoken explicitly by another task (Vresume).

There are special Vsuspend wait situations that are displayed under a specific name.

More information: Vsuspend Task States table

Vvectorio

Vector IO

Task is executing a vector I/O operation (read or write).

-

Volume Format

Task is formatting volume(s).

-

IOComPort Wait

Task is waiting for an I/O order confirmation from the I/O completion port.

-

Aborting

Task is exiting the database session.

Yielding

-

Task gives up control voluntarily.

-

Initialized

Task was initialized.

WaitForEvent

Wait For Event

Task is waiting for an event.