Procedure documentationDisplaying Information About Tasks Locate this document in the navigation structure

Prerequisites

You are logged on to the database as the database system administrator.

Procedure

  1. Select the database in the explorer tree.

  2. In the context menu of the database, choose Administration.

  3. Open the Task Manager tab page.

    The running tasks are displayed.

    Task Types

    Name

    Description

    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.

    Task States

    Old Name

    New Name

    (as of software version 7.7.03.15 )

    Description

    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.

  4. You can show and hide tasks according to the following criteria:

    • Active: running tasks

    • Runnable: tasks that could run

    • User: user tasks

    • System: all tasks other than user tasks

    • All: all tasks

  5. To display further information about a task, select the task and choose Details for Tasks underneath the task overview.

Time Measurement

In the task overview, you can also activate or deactivate the database-internal time measurement of database activities.

Caution Caution

Only activate time measurement when asked to do so by support.

Time measurement has a negative impact on the performance of your system.

End of the caution.

If internal time measurement is active, the system collects detailed information about database activities (for example, the average response times of SQL statements or the duration of log I/O operations). This information is used, for example, by the Database Analyzer or XCONS.

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