Profile Parameters for the Standalone Enqueue Server

Use

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 further down.

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. Caution Set this parameter only in the instance profile of the enqueue server.
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 For information about using the backup file for locks transferred to the update process when using the replication server, see Using the Backup File.
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 The value is the four digit number of the SAP character set.
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 standard value is 1000. Caution Set this parameter only in the instance profile of the enqueue server.
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 (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 standard value is 1000.

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

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

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 should be between 30000 and 100000. 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 down-sizing) and 1000000. If the value is so small that there is not enough space for all the lock entries, the response is accordingly cut off when it is read. 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.	Integer value	10000

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

enque/snapshot_pck_size

This parameter determines the size of the individual packets. Values should be between 30000 and 100000. 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 down-sizing) and 1000000. If the value is so small that there is not enough space for all the lock entries, the response is accordingly cut off when it is read.

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.

Integer value

10000

Parameters for 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:

Replication and Failover

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