Configuring Multiple Instances Of Historical Server; When To Create Multiple Instances Of Historical Server - Sybase 12.5.1 User Manual

Configuring multiple instances of Historical Server

When to create multiple instances of Historical Server

User's Guide
Parameter Description
hsName Name of Historical Server as it appears in the interfaces file. If
-S
omitted, the Historical Server name defaults to the value of the
DSLISTEN environment variable. If DSLISTEN is not set, the
name "histserver" is used.
Displays Historical Server version information and exits, ignoring
-v
all other parameters.
There are times when running more than one instance of Historical Server is
appropriate. However, you must configure the multiple instances correctly to
either allow or restrict user access to the recording sessions of the multiple
instances.
This section discusses:
• When to create multiple instances of Historical Server
• Configuring an additional Historical Server on UNIX platforms
• Configuring an additional Historical Server on Windows NT
If a single instance of Historical Server is managing many concurrent recording
sessions that have short sample intervals, the amount of time required to
process and record the samples may interfere with the timely acquisition of
new samples. If the timestamps in the recorded data files indicate that samples
are not being collected at a reasonable approximation of the requested sample
interval, you may choose to spread the load among two or more instances of
Historical Server.
When multiple instances of Historical Server use the same home directory:
• Each instance must be started by the same operating system account.
• All instances that use the same home directory use the same control file.
• The sessions recorded by one instance are visible to the other instances.
• File-locking mechanisms ensure that the control file is not corrupted by
concurrent accesses.
CHAPTER 2 Configuring Historical Server
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