The Properties tab for a query module enables you to view and set project properties.
Project path shows the location of your project file.
Module path shows the location of your query module file.
Accelerated Playback allows you to set the Accelerated playback rate to specify a faster or slower rate at which the project should be run. The default setting is 1.0, for real time. To increase the speed, set the number to a value larger than 1.0; to decrease the speed, set the number to a value smaller than 1.0.
After adjusting the rate, time-based operations are accelerated or decelerated proportionately. Adjusted-rate playback is only available for applications that use input files, since the arrival of rows from other kinds of external data sources cannot be adjusted by Sybase CEP Engine.
Persistence allows you to determine state persistence for the query module. When you select the Enable persistence for this module check box, Sybase CEP Server saves information about the state of the module CCL statements, named windows, data streams, and adapters to disk at the interval specified in the Commit interval field. This information can later be used to recover data in case of server failure. You can enable or disable persistence for every query module individually. You specify the commit interval in CCL Interval format. See "Time Literals" in the Sybase CEP CCL Reference Guide for more information about valid formats. If you enter a positive integer without any further qualifier, Sybase CEP Engine interprets it as a number of microseconds.
The Properties tab for a query submodule includes the Inherit persistence settings from the parent module check box. When you select this check box, the submodule uses the same persistence settings as its parent.
Note that, in cases where a parent module and its submodules specify different commit intervals, the parent module and all of its submodules use the shortest specified interval.
A data stream always inherits its persistence settings from its query module or submodule.
Enabling persistence can have a significant negative impact on performance.
The Synchronization area contains properties that correct synchronization problems in a module's streams. These settings are automatically inherited by all of the module's input streams and submodules, but settings for specific streams and submodules can be overridden, as explained here and in Properties Tab for a Data Stream.
Selecting Use message timestamp makes available several synchronisation options:
The Maximum delay field allows Sybase CEP Server to correct synchronization problems among rows arriving in different input streams in a module. When necessary, Sybase CEP Server retains incoming rows up to the interval specified in the Maximum delay field, before sorting the order in which they arrive in their respective streams. Since different streams can have Maximum delay set to different values, the largest setting of this field among the different streams attached to the module is used to determine the overall Maximum delay interval for the module. Maximum delay should not be set to 0.
Selecting Messages can come out of order enables an additional feature that works with the Maximum out of order delay field, allowing Sybase CEP Server to correct synchronization problems on a given input stream. When selected, Sybase CEP Server retains rows arriving in the input stream for the interval specified in the Maximum out of order delay field, before ordering them by timestamp and delivering them into the stream. This ensures that any synchronization problems between Sybase CEP Server and outside data sources encountered in the specified time period are resolved before the rows are fed into the stream. If the Messages can come out of order check box is not selected, any row that arrives with an earlier timestamp than the row currently in the stream is discarded.
The Maximum out of order delay field accepts any valid CCL INTERVAL type, as described in the Sybase CEP CCL Reference Guide. If you enter a positive integer without any further qualifier, Sybase CEP Engine interprets it as a number of microseconds.
Note the difference between Maximum delay and Maximum out of order delay. The first interval controls synchronization among all of the external input streams in a module. The second interval controls synchronization only for rows arriving in a single stream.
Selecting Use current server timestamp causes rows arriving in a stream to be assigned a timestamp by Sybase CEP Server, based on the current time. This timestamp overrides and replaces the timestamp set by the adapter.
You should use this setting when it is not important to you to know when rows arrive in the module's streams. With this setting enabled, no rows are marked as arriving out of order.
Inherit settings from the parent module sets a submodule’s synchronization options to those of its parent module.
The Guaranteed Delivery area contains settings that allow you to specify Guaranteed Delivery options. These settings are automatically inherited by all of the module's streams, but settings for specific streams can be overridden, as explained in Setting Data Stream Properties.
Guaranteed delivery only works in combination with input or output adapters that support the Guaranteed Delivery feature, and only if Guaranteed Delivery is enabled for those adapters. For more information, see the Sybase CEP Integration Guide. Guaranteed Delivery features by themselves do not guarantee delivery of rows if the Container process of Sybase CEP Server on which the project is running fails. A combination of Persistence and Guaranteed Delivery guarantees delivery of rows even in cases of Container failure.
Enable guaranteed delivery for this module turns on Guaranteed Delivery, which guarantees that every row is received by its destination at least once, as long as the software components are running.
The Maximum number of messages box specifies the maximum number of messages to hold in the Guaranteed Delivery queue. Messages that arrive when the Guaranteed Delivery queue contains this maximum number are discarded. The default setting of 0 (or clearing this box) places no limit on the number of messages in the queue.
The Maximum message age box specifies the maximum permitted age of messages in the Guaranteed Delivery queue. Messages that exceed the allowed age are removed from the queue and discarded. This value is a CCL INTERVAL type, as described in the Sybase CEP CCL Reference Guide. If you enter a positive integer without any further qualifiers in this field, Sybase CEP Engine interprets it as a number of microseconds. Leaving this field blank, or entering 0 in this field, places no limit on the age of messages in the queue.
Messages in the Guaranteed Delivery queue are stored in memory. If you do not place a limit on the size of the queue, or place too high a limit on the queue, you run the risk of causing Sybase CEP Server to run out of memory.
Inherit settings from the parent module sets a submodule’s Guaranteed Delivery options to those of its parent module.
The Clustering area contains the Number of project instances box, which specifies how many instances of a project to run. This feature is set from the main query module for all modules in a project. To use the parallel query feature, set the number of instances for a project to two or more.
The Error Recovery area contains the Restart project on failure check box, which allows you to specify that the project containing the selected query module should automatically restart following a fatal error.
Note that adapters are not automatically restarted by selecting this option.
If the fatal error is not transient, a project set to restart automatically can enter a continuous restart loop, which can be broken by stopping the project.