TS/MP 2.5 System Management Manual

CREATEDELAY and DELETEDELAY
CREATEDELAY is the length of time a send request queues before the link manager asks for another
link, assuming the link manager has determined that no more static links are available (that is, only
dynamic links are available).
A link manager will always ask for a link immediately if the link manager has determined that
static links are still available.
The DELETEDELAY attribute specifies the amount of time that a dynamic server sits idle before the
link manager returns the link to the PATHMON process.
For more information about static and dynamic servers, see “Configuring Server Classes” (page 61).
Understanding the Effects of Link Configuration
Application performance often depends on how well links between requestors and server processes
are managed. If your application is configured in a way that creates requestor queuing problems
or a bottleneck in server process responses, performance suffers.
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 might 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
ACS subsystem 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.
Figure 20 Link Configuration With MAXSERVERS Set to 1
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 ACS subsystem
Configuring Links for Optimum Performance 69