## Overview of the Task States

### Use

The task state shows whether a task is active and which action it is currently executing.

Overview of the Task States

Name | Description
AsynClose | Task is closing I/O ports after backup or restore
AsynCntl | Task is determining parameters or initializing a backup device
AsynIO | Task is executing an asynchronous I/O operation (during backup or restore)
AsynOpen | Task is opening I/O ports for the backup or restore
AsynWaitRead/Write | Task is waiting for the end of an I/O operation during backup or restore
Command reply | Task is sending the result of a request to the application
Command wait | Database session without a request
Connect wait | Free database session
DcomObjCalled | Task is executing a database procedure or a COM object
Diaginit | Task is initializing the database-internal trace file
Inactive | Task is in an initial state and has no resources (such as a stack)
InsertEvent | Task is generating an event
IO wait (W/R) | Task is waiting for the result of an I/O operation (W: write, R: read)
Locked | Task was locked as the kernel was shut down (to avoid this task being rescheduled)
RescheduleMsec | Short-term wait situation, task runs again automatically after a predefined time span (in microseconds)
Runnable | Task can run now, but has been displaced due to long runtime or priority of another task
Running | Task is running, using CPU
sleep | Short-term wait situation, task runs again automatically after a predefined time span
Stopped | Task was suspended by the kernel and is waiting to run again
Terminated | Task or database session was ended
UNKNOWN | Task state is unknown
Vattach | Task is opening I/O ports (volumes, normal operation)
Vbegexcl | Task is waiting to enter a protected area
Vdetach | Task is closing I/O ports (volumes, normal operation)
Vdevsize | Task is determining the size of a volume or formatting a volume
Vdualvectorio | Task is performing a vector I/O operation (read or write) on two volumes in parallel
Vendexcl | Task is leaving a protected area
VenterRWRegion | Task is waiting to enter a protected area (reader/writer region)
Vfclose | Task is closing a file
Vfopen | Task is opening a file
Vfwrite | Task is writing to a file
VleaveRWRegion | Task is leaving a protected area (reader/writer region)
Vopmsg | Task is writing a message to one of the following database files: knldiag, knldiag.err, opmsg[n]
Vrelease | Task is ending the database session
Vshutdown | Task is changing the operational state of the database instance from ONLINE to ADMIN

Vsuspend

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

There are special Vsuspend wait situations that are displayed under their own names. The following list shows the most important of these states.

TableRootExc l: can occur while accessing B* trees that represent permanent data
A task is trying to set an exclusive lock on the root page of a B* tree but has to wait due to a lock collision. Tasks request exclusive locks on B* trees for structure-changing operations such as tree balancing, among other operations.

TableRootShare: can occur while accessing B* trees that represent permanent data
A task is trying to set a shared lock on the root page of a B* tree but has to wait due to a lock collision. As a rule, all operations on a B* tree begin with a shared lock, which is refined as the operation descends into the B* tree, that is, it is extended to become an exclusive or shared lock on the leaf level.

TableNodeExcl, TableNodeShare: analogous wait states for lock collisions on the leaf level

For B* trees that represent an index or temporary data, there are similar states, such as InvRootExcl, InvRootShare, InvNodeExcl, TempRootExcl and TempRootExcl.

For page chains, there are similar states, such as ObjRootExcl, ObjNodeExcl, ObjNodeShare, UndoRootExcl, UndoRootShare and UndoNodeExcl.

DC OvFlow: The data cache is operating at capacity and cannot accept any new data. Only when pages have been written from the data cache to the volumes can the data cache accept new pages. If you frequently observe DC OvFlow states, check whether your data cache is large enough or the I/O system too slow.

LogQ FULL: The log queues are operating at capacity and cannot accept any new redo log entries. Only when the log writer has written data from the log queues to the log area can the log queues accept log entries again. If you frequently observe LogQ Full states, check whether your log queues are too small or the I/O system too slow.

DB FULL: The data area is full and cannot accept any more pages. Add a new data volume.

Vvectorio | Task is executing a vector I/O operation (read or write)
Vwait | Task is waiting to be awoken explicitly by another task (Vsignal) Example: task is waiting for an SQL lock
WaitForEvent | Task is waiting for an event

### Activities

To display information about tasks, use the Database Manager or XCONS or in SAP systems the database assistant or liveCache assistant. See

● Database Manager GUI, Displaying Database Sessions

● Database Manager CLI, show

● XCONS documentation

● Database Administration in CCMS: MaxDB, Task Manager

See also:

Overview of Tasks

Process Structure