RAPStore Subscriber Message-Loading Performance Parameters

Improve message-loading performance of the RAPStore subscriber.

Note: Sybase recommends the subscriber configuration directory that contains the XML-based message template definitions (for example, <RAP>/RAPStoreSubscriber/templates). The RAPStore subscriber allocates database connections and other system resources for processing each message definition template. Removing extraneous message template definition prevents the allocation of these resources and improves message-load performance.

RAPStore subscriber configuration
Parameter	Description
Primary File Location	These parameters indicate the storage location of binary files with data to load into the RAPStore. For optimal system performance, store these files on separate disk controllers than both the RAPStore database devices and the Overflow File Location parameter. Note: To take advantage of multiple disks to improve the file read/write performance multiple Primary File Location elements, enter multiple primary file locations.
Overflow File Location	The Overflow File Location is used only used when the PrimaryFileLocation is full. For optimal system performance, store these files on separate disk controllers than both the RAPStore database devices and the Primary File Location parameter.
I/O Buffer Size	Determines the amount of data stored in memory per database table before it is written to file. Larger values for this parameter result in higher system throughput, but the parameter is constrained by the amount of available system memory.
Number Of I/O Buffers	I/O buffers are in-memory storage locations that allow the system to continue to receive data when it is writing previously received data to a file. This parameter determines the number of I/O buffers that are created per table. Increasing the number of I/O buffers beyond a value of 4 does not improve system performance.
Target File Size	Size of each binary file that is loaded into the RAPStore. Larger values for this parameter increase the system latency. Small values affect system performance due to the I/O consequences of writing out and loading many individual files.
Idle Buffer Write Delay	Number of seconds to wait before data is written out to file when the system is not receiving data from the publisher. Larger values for this parameter increase latency when data flow is not steady. Very small values increase the file overhead costs in the system, and reduce performance.
Buffer Age Limit	Number of milliseconds to wait before data is transferred to the RAPStore when the system is receiving a relatively small amount of data from the publisher at very low frequencies, for example, if only one message is received every second. Larger values for this parameter increase latency in situations where flow is at a low rate. Very small values increase file overhead costs, and reduce performance.
Referential Integrity Checks for Market Data	By default, enabled. Controls whether database-related referential integrity checking is performed while loading market data into the RAPStore database. Disabling this parameter improves load performance since by bypassing the expensive process of referential integrity constraint checking. However, you must decide, based on the origin and nature of the data being loaded, if these checks can be safely omitted. Loading data that bypasses referential integrity checks may result in incorrect results from queries executed using the RAPStore database.