TS/MP System Management Manual (H06.05+, J06.03+)

Configuring Objects in a PATHMON Environment
HP NonStop TS/MP System Management Manual—541819-007
3-27
Understanding the Effects of Link Configuration
Suppose, for example, that you set the server attribute LINKDEPTH equal to 20, which
permits 20 concurrent requests to a server process. If transaction service time is 1
second and the server class handles requests serially, response time might be as
much as 20 seconds. Thus, this LINKDEPTH setting can cause send requests to
queue on the server class for unacceptable lengths of time.
As another example, suppose MAXLINKS is 1 and you also set the server attribute
MAXSERVERS to 1, indicating that only one server process can run in this server
class at a time. If this setting is too low, send requests may queue for the link manager
because the PATHMON process cannot create another server process to satisfy the
link requests. This situation is illustrated in Figure 3-5, which shows a server class that
allows only one server process to run at a time. The server process can handle only
one request: Request 1 from TCP-1. Other requests, from TCP-1, TCP-2, and the
LINKMON process, are waiting to be processed. The problem is further complicated
by the fact that if TCP-1’s link is a static link, the TCP will not necessarily return the link
automatically.
Consider this configuration for a server class:
MAXLINKS = 5
LINKDEPTH = 1 (suggested general value)
MAXSERVERS = 1
This configuration specifies that a maximum of five links to each server process in this
server class is allowed; each link manager can have only one link to each server
process in this class; and only one server process can run in this class at any one time.
Consequently, if a LINKMON process is managing five requester processes, and each
process sends a request to this server class, four processes must wait for the one link
Figure 3-5. Link Configuration With MAXSERVERS Set to 1
PATHMON
Server Class
TCP
LINKMON or
ACS subsystem
processes
TCP
1 server process
running
MAXLINKS = 1
MAXSERVERS = 1
Request 1 - processing
Request 2 - waiting
Request 3 - waiting
Request 5 - waitin
g
Request 6 - waitin
g
Request 7 - waitin
g
Request 4 - waiting
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