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Use

The enqueue service allows ABAP applications to lock data so that only they can use it. The locking of the data avoids parallel changes to the data, which would lead to data inconsistency.

Features

In the monitoring infrastructure, there are various subtrees for monitoring the enqueue. These are combined in this monitor:

Subtree Enqueue → Enqueue Server

This subtree includes a large number of monitoring values for the enqueue service. Since the monitor is supplied with values by an ABAP data collection method, the values are updated every five minutes. The subtree is constantly supplied with values, regardless of whether the enqueue service is running on a normal instance or is implemented as a standalone enqueue server.

The following table provides information about the monitoring tree elements (MTEs) of this subtree:

MTE Name (MTE Class) Meaning

Enqueue Server (R3EnqueueStat)

Enqueue server that provides the enqueue service for the system

 Enqueue Requests    (R3EnqueueStatEnqReq)

Number of lock requests

 Enqueue Request Rejects    (R3EnqueueStatEnqRej)

Number of rejected lock requests

 Enqueue Requests Errors    (R3EnqueueStatEnqErr)

Number of errors that occurred during lock requests

 Dequeue Requests    (R3EnqueueStatDeqReq)

Number of release requests (DEQUEUE)

 Dequeue Requests Errors    (R3EnqueueStatDeqErr)

Number of errors that occurred when releasing locks

 DequeueAll Requests    (R3EnqueueStatDeqAll)

Number of releases of all locks of an LUW (such as at the end of an LUW)

 CleanUp Requests    (R3EnqueueStatCleanReq)

Number of releases of all locks of an application server (such as when the server is started or shut down)

 Backup Requests    (R3EnqueueStatBackupReq)

Number of update calls for which locks were forwarded to the update. The update process receives the lock owner ID of the caller, the caller receives a new lock owner ID.

 Reporting Requests    (R3EnqueueStatReportReq)

Number of operations for reading the lock table.

 Owner Names    (R3EnqueueStatOwnerNames)

Maximum number of lock owner IDs that can be stored in the lock table. Lock owner IDs are assigned to a user context or to an update request.

 Owner Names Peak Utilization    (R3EnqueueStatOwnerNamesPeak)

Maximum number of lock owners that have been stored simultaneously in the lock table.

 Owner Names Actual Utilization    (R3EnqueueStatOwnerNamesUtil)

Current number of lock owners in the lock table

 Granule Arguments    (R3EnqueueStatGranuleArg)

Maximum number of different lock arguments that the lock table can contain; locks of different owners or with different lock modes, but with the same lock argument occupy one entry

 Granule Arguments Peak Utilization    (R3EnqueueStatGranuleArgPeak)

Maximum number of different lock arguments that have been stored simultaneously in the lock table.

 Granule Arguments Actual Utilization    (R3EnqueueStatGranuleArgUtil)

Current number of different lock arguments in the lock table

 Granule Entries    (R3EnqueueStatGranuleEntries)

Maximum number of elementary locks that the lock table can contain (each elementary lock occupies one entry)

 Granule Entries Peak Utilization    (R3EnqueueStatGranuleEntriesPeak)

Maximum number of elementary locks that have been stored simultaneously in the lock table.

 Granule Entries Actual Utilization    (R3EnqueueStatGranuleEntriesUtil)

Current number of elementary locks in the lock table

 Update Queue Peak    (R3EnqueueStatUpdQuePeak)

Maximum number of open update requests with locks that has occurred so far

 Update Queue Actual    (R3EnqueueStatUpdQueActual)

Current number of open update requests with locks

 Total Lock Time    (R3EnqueueStatTotLockTime)

Total time spent in the critical path of the lock table for lock operations

 Recent Lock Time (per minute)    (R3EnqueueStatLockTime)

Time spent in the critical path of the lock table for lock operations (in seconds per minute)

 Total Lock Wait Time    (R3EnqueueStatTotLockWaitTime)

Total wait time of parallel processes before entering the critical path of the lock table

 Recent Lock Wait Time (per minute)    (R3EnqueueStatLockWaitTime)

Wait time of parallel processes before entering the critical path of the lock table (in seconds per minute)

 Total Server Time    (R3EnqueueStatTotServerTime)

Total time spent in the enqueue server

 Recent Server Time (per minute)    (R3EnqueueStatServerTime)

Total time spent in the enqueue server (in seconds per minute)

 Runtime of Data Collector    (R3EnqueueStatDataCol)

Node that is assigned to the data collection method; this is used to monitor the runtime of each data collection

Subtree <SysID>\<Instance with Enqueue Service>\...\Enqueue

This subtree includes only the most important monitoring values for the enqueue service. Since the data is supplied by an active data supplier directly from the kernel, current data is reported immediately in the monitoring infrastructure. However, this subtree does not exist if the enqueue service is implemented as a standalone enqueue server.

The subtree contains the following MTEs:

MTE Name (MTE Class) Meaning

<SysID>\<Instance>\...\EnqueueServer (R3EnqueueServer)

Subtree for the enqueue client; this only exists on the central instance

 Utilization Owner Names    (R3EnqueueUtilOwner)

Current number of lock owners in the lock table as a percentage of the maximum number

 Utilization Granule Arguments    (R3EnqueueUtilArguments)

Current number of different lock arguments in the lock table as a percentage of the maximum number

 Utilization Granule Entries    (R3EnqueueUtilEntries)

Current number of elementary locks in the lock table as a percentage of the maximum number

 QueueLength    (R3EnqueueQueueLength)

Length of the enqueue queue as a percentage of its maximum length

 ErrorsInWpENQ    (R3ErrorsInWpENQ)

Number of errors in the enqueue work processes since the monitoring segment was created (that is, since the application server was started)

 ErrorFreqInWpENQ    (R3ErrorFreqInWpENQ)

Number of errors in the enqueue work processes per minute

 EndedWpENQ    (R3EndedWpENQ)

Number of enqueue work processes terminated after an error; you can use the Process Overview (transaction SM50) to determine whether a work process should be restarted after an error

Subtree Enqueue Clients

Every instance of a system is connected to the enqueue service. This monitoring object contains performance attributes for requests from the other instances to this service.

The subtree contains the following MTEs:

MTE Name (MTE Class) Meaning

Enqueue Clients

Performance attributes for requests from the instances to the enqueue service

 <Hostname>_<SysID>_<InstNo>    (R3EnqueueClient)

Instance name

 EnqueueFreq       (R3EnqueueFreq)

Enqueue operations (logical data locks) per minutes that are coming from another instance to the central instance

Subtree Connection to Standalone Enqueue

If the system contains a standalone enqueue server, this subtree provides information about the status and high availability configuration of that server.

The subtree contains the following MTEs:

MTE Name (MTE Class) Meaning

Connection to Standalone Enqueue

Subtree for the standalone enqueue

 <host name>_<SysID>_<Inst. No>    (ensaHaMO)

Instance name

 Server       (ensaLocationTxt)

Host on which the standalone enqueue server is running.

 Status       (ensaStatusHA)

Status of the standalone enqueue server

 Replication Status       (ensaReplStatusHA)

Together with an enqueue replication server, the standalone enqueue server forms a high-availability enqueue server. If a replication server is installed, its current status is displayed here.

Note

The instance-specific subtree containing information about the standalone enqueue server is displayed for every instance that is monitored by an instance agent. This results in the following recommendations:

  • If you only want to monitor the general availability of the standalone enqueue server, ensure that at least one constantly-available instance is monitored with an agent (more information: Registering SAP NetWeaver Components and Hosts in CEN).
  • If you also want to monitor the connection of every instance to the standalone enqueue server, ensure that all instances are monitored with the SAPCCM4X agent.

Activities

To start the monitor, follow the procedure below:

  1. Start the Alert Monitor using transaction RZ20 or choose CCMS → Control/Monitoring → Alert Monitor.
  2. On the CCMS Monitor Sets screen, expand the SAP CCMS Monitor Templates set.
  3. Start the Enqueue Server monitor from the list by double-clicking it.