Performance Tuning for Content Manager

Chapter 14. Maintenance 407

Figure 14-3 shows the Staging Area properties window, which is accessed

through the Content Manager system administration client. Right-click the

Resource Manager database and select Staging Area.

Figure 14-3 Staging Area properties window

Defining the maximum size of the cached object. The system will not cache

objects that exceed the maximum size; however, if you decrease the maximum

size and objects that were stored earlier exceed the new maximum size, the

system will retain these existing objects.

14.4.1 Purger process

The purger process is used to maintain the size of the staging area. When the

staging area size reaches a preset upper limit, the purger will begin to remove

files until it reaches a preset lower limit. Using Figure 14-3 as our example, this

means that our staging area is 199 MB in size, and purging will commence when

this 199 MB area is 80% (159.2 MB) full if the purger process is started. When

the staging area reaches 159.2 MB full in size, the purger will start randomly

deleting files until the staging area reaches 60% of 199 MB (119.4 MB).

408 Performance Tuning for Content Manager

All of the staging area values are configurable. For example, if you want to

completely clear the staging area, you can set the start purge size to 1% of the

maximum staging area, and the stop purge size to 0% of the maximum staging

area size. Figure 14-4 shows this configuration.

Figure 14-4 Configuration to clear staging area completely

With the configuration set in Figure 14-4, you should be able to clear the entire

staging area, assuming that the staging area is at least 1% of 199 MB full at the

time. If the staging area is below 1% full at the time, you need to reduce the size of

the staging area from 199 MB to a size where 1% of the staging area maximum

size was smaller than the currently occupied space in the staging area.

The staging area maximum size and purge rates are monitored periodically, not

constantly. For this reason, you might need to wait up to five minutes, the default

setting, before changes you have made to the staging area come into effect. The

cycle time for this checking is configured via the Resource Manager configuration

window. To open this window, go to the Content Manager system administration

client, open a Resource Manager, and select Configurations. Then select the

Resource Manager configuration that you are currently using (the default is

IBMCONFIG), and select the Cycles tab (Figure 14-5 on page 409).