DQE Property Editor (SAP Library

DQE Property Editor

Definition

A portal utility for configuring property values related to the performance of the Distributed Query Engine (DQE).

Use

The DQE service exposes methods to access and update essential properties through the administration tools. Eleven properties are exposed and configurable by means of the DQE Property Editor. These properties are shown in the table below.

The value type of all the properties is integer, except for Storage Directory and Log Level. For each property, the default value appears as initially configured within the DQE. In addition, in the property description table below, the minimum and maximum values, and the increment to use when changing the property values, are specified. There are no firm rules for the maximum and increment values for some properties; these have been specified with a “?” to denote that you can choose alternative values. The following is a list of the properties.

Property	Description	Default [Min, Max, Increment]
Process Pool Maximum Threads	Maximum number of threads allowed to be pooled for processing at any given time	15 [1, 100?, 1]
Process Pool Thread Time To Live	Time-to-live for process pool thread, in milliseconds	120000 [1000, 3600000?, 1000?]
Process Timeslice	The period of time allowed for which a process for a single query is allowed to run uninterrupted, in milliseconds	2000 [100, 10000?, 100?]
Buffer Memory Available	The amount of memory that buffer management should use, in megabytes	128 [1, 2048?, doubling]
Buffer Active Memory Threshold	The percentage of buffer management that serves as a threshold for active memory management	90 [1, 100, 1]
Buffer Management Interval	The maximum size of a batch sent between connector and query service. Should be even multiple of processor batch size	1000 [500, 3600000?, 500]
Connector Batch Size	The maximum size of a batch sent between connector and query service. Should be even multiple of processor batch size	1000 [500, 10000, 500]
Processor Batch Size	The maximum size of a batch sent internally within the query processor. Should be <= the connector batch size	500 [500, 10000, 500]
Storage Directory	The location to store temporary buffers too large to fit in memory	../<path_to_storage_location>
Maximum Open Files	The maximum number of open file descriptors that should be cached in the storage directory. Normally depends on OS settings for # open files per process	10 [1, 256, 1]
Log Level	DQE logging level. See Logging section	See “Choosing a Log Level” below

To access the DQEProperty Editor:

In the portal top-level navigation, choose System Administration ® Distributed Query Engine ® Configuration.

After changing property values, you can save them or restore them to the default values.

Note

Modified properties become effective by restarting the J2EE Engine.

Choosing a Log Level

The logging levels which can be set for the DQE server are described in the table below. In the DQE Property Editor, choose a log level name from the drop-down list.

Log Level	Log Level Name	Description
0	NONE	No logging
1	CRITICAL	Generally used to record an event or error that must be recorded (if any logging is used). If it is used to record an error, it usually means that the system encountered a critical error that affects the integrity, accuracy, reliability and/or capability of the system.
2	ERROR	Error messages are generally used to record unexpected problems, or errors that are not critical in nature and from which the system can automatically recover.
3	WARNING	Warning messages generally describe expected errors from which the system should recover. However, this level is used to record the fact that such an error or event did occur.
4	INFO	This level of logging is the usually the normal level. All interesting periodic events should be logged at this level so someone looking through the log can see the amount and kind of processing happening in the system.
5	DETAIL	Such messages are moderately detailed, and help to debug typical problems in the system. Generally, these messages are not so detailed that the big picture gets lost.
6	TRACE	The most detailed logging level, used to trace system execution for difficult problems. At this level, logging may be so verbose that system performance may be affected.