Increasing RAPStore Subscriber Message-Loading Performance

Improve message-loading performance of the RAPStore subscriber.

Note: Sybase recommends that the subscriber configuration directory that contains the XML-based message template definitions (for example, <RAP>/RAPStoreSubscriber/templates) should contain only definitions for the messages that are being loaded by the subscriber into the RAPCache database. This is because the RAPStore subscriber allocates database connections and other system resources for processing each message definition template. Remove the extraneous message template definition files to prevent the allocation of these resources and improve message load performance.

RAPStore subscriber configuration
Parameter	Description
Primary File Location and Overflow 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 rather than in the RAPStore. Place the primary and overflow locations on separate file systems.
I/O Buffer Size	Determines the amount of data that is stored in memory per database table before the data is written out to a 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	Determines the 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	Determines the 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 in situations where data flow is not steady. Very small values increase the file overhead costs in the system, and reduce performance.
Buffer Age Limit	Determines the 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	This is an optional parameter which, by default, is enabled. It controls whether database-related referential integrity checking is performed while loading market data into the RAPStore database. Disabling this parameter improves load performance since it bypasses 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.