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Background documentationProfile Parameters for the Standalone Enqueue Server Locate this document in the navigation structure

 

You have to set the following parameters in the instance profile of the standalone enqueue server.

Some are only relevant, if you are working with a replication server. These are listed later.

Parameter

Meaning

ipc/shm_psize_34

The log table is stored in the shared memory of the enqueue server, and its shared memory key is 34. On some platforms the enqueue server by default puts the lock table in pool 10. In this case this would be a waste of shared memory. If you set this parameter to 0, the lock table is not placed in any pool. As much memory as is needed for the lock table is allocated.

So set the parameter ipc/shm_psize_34 = 0 in the profile of the enqueue server.

Caution Caution

Set this parameter only in the instance profile of the enqueue server.

End of the caution.

enque/server/replication

The parameter can have the value true or false and this determines whether the enqueue server uses the replication server. Default value: false If you want to use the replication server, you have to explicitly set this parameter in the enqueue server profile.

Note Note

For information about using the backup file for locks transferred to the update process when using the replication server, see Using the Backup File.

End of the note.

enque/server/codepage

The non-unicode version of the enqueue server can run in specific code pages. Until now this was only useful, if you were using an Application Server Java (J2EE Engine) with the enqueue server and the enqueue server was not a Unicode server. In the protocol used in such cases, unicode characters are transferred in UTF8 format to the enqueue server. With this parameter you can set the code pages you want to convert these characters to.

Note Note

The value is the four digit number of the SAP character set.

End of the note.

enque/server/max_requests

The parameter specifies the maximum number of enqueue requests that can be processed simultaneously in the enqueue server.

The value should be at least the same as the total number of work processes in the system (for AS Java, the total number of threads in all AS Java instances). The default value is 1000.

Caution Caution

Set this parameter only in the instance profile of the enqueue server.

End of the caution.

enque/encni/port

You use this parameter, if the TCP port of the enqueue server, used for the communication with the enqueue clients, is not to be set to sapdpXX (XX is the instance number). It must then be set in all profiles (preferably DEFAULT.PFL).

enque/encni/repl_port

Use this parameter if the replication port of the enqueue server cannot be set to the default port 5XX16 (where XX is the instance number). It should then be set either in DEFAULT.PFL, or in the profiles of the enqueue server and the replication server.

enque/encni/no_addr_resolve

This parameter deactivates the host name resolution in the enqueue server. The default value of the parameter is zero 0 (false), this means that the host name resolution in the enqueue server will be executed. If this takes too long or there are any problems, you can set the parameter to 1 ( true), the IP address is simply output and the host name is not resolved.

More information: High Availability with the Standalone Enqueue Server

enque/server/threadcount

The number of I/O threads. Normally you do not need to change this parameter. It may be useful to change it for increasing system performance, but this should only be done with support from SAP or your hardware provider. Experience up to now shows that a value higher than 4 has never resulted in an increase in throughput.

enque/server/max_clients

This parameter determines the number of processes that can be connected to the enqueue server. Set the parameter to the same value as the total number of work processes in the system. The default value is 1000.

enque/server/use_spinning

With this parameter you can activate a different mechanism for communication between the threads. This mechanism is somewhat quicker, but generates a heavy load on the system. Even with a small enqueue throughput, CPU usage will be 100%. Possible values are true and false. The default value is false, and the parameter is not normally set.

Snapshot Parameters

In some cases the result of an enqueue request (read) is too large to be transported in one packet across the network. The result must then be split into several packets that are stored on the server and fetched one after another by the client.

The following parameters control the behaviour and resource consumption in this process.

Recommendation Recommendation

These parameters are assigned default values. The values only have to be changed for very special requirements (for instance down-sizing).

End of the recommendation.

Parameter

Meaning

Unit

Default Value

enque/snapshot_timeout

If the client is terminated, to prevent memory leaks once a timeout is exceeded the server must delete these packets.

This parameter determines the timeout.

Seconds

10

enque/snapshot_pck_size

This parameter determines the size of the individual packets. Values between 30000 and 100000 are preferable. A lock entry requires about 1 KB.

Bytes

50000 (50 KB)

enque/snapshot_pck_ids

This parameter determines the maximum number of snapshot packets. Possible values are between 10 (extreme downsizing) and 1000000. If the value is that small that there is not enough space for all the lock entries, the entries will be truncated when you call them up.

Example Example

If you set enque/snapshot_pck_size=30000 and enque/snapshot_pck_ids=10, you can read out a maximum of about 300 lock entries. This is only useful for very small systems or applications.

End of the example.

Integer value

10000

Parameters for Using Replication

You have to set the following parameters if you use replication, that is, when the value of enque/server/replication is true.

More information:

The Replication Process

Polling Concept.

Parameter

Meaning

enque/enrep/stop_timeout_s

This parameter specifies how long the enqueue server is to remain in suspended state, before it attempts to update the replication server again. The time period is specified in seconds. The value 0 means that the state suspended remains for as long as there is a connection to the replication server. Only when the replication server is restarted, does the enqueue server leave this state.

enque/enrep/stop_retries

This parameter specifies how often the enqueue server attempts to update the replication server, following the timeout stipulated in enque/enrep/stop_timeout_s. Possible values are whole numbers. The value 0 means that the enqueue server should keep retrying.

enque/enrep/req_block_count

This parameter specifies how many memory blocks (each has 32 KB) are reserved in the replication server for transferring the data. The parameter is needed with a lock table size exceeding 80 MB.

Caution Caution

If your lock table is larger than 80 MB, see note 654744.

End of the caution.