Chapter 3. Tuning WCS instance 41
Ensure directories contain less than 1,000 files. This number has to be
manually calculated by dividing Maximum objects per member by Cache
directories per member. For example, if you expect one store to have 50,000
files, you will need 50 cache directories (dividing 50,000 by 1,000) to store
less than 1,000 files in each directory. Set the value of the Cache directories
per member field appropriately.
If pages do not need to be automatically removed from the cache, ensure that
the Auto Page Invalidation box is not checked.
If any number of files can be in the cache, set the Max Objects Per Member
field to 0. This allows unlimited number of objects in the cache.
After making changes in the cache manager, be sure to stop and re-start the
WCS instance from the WebSphere Application Server Administrative
Console. Also, stop and re-start the Web server.
3.5 Setting up caching in 3-tier topology
In a 3-tier toplogy scenario, the web server is running on a machine separate
from the WAS machine. To serve requests for cached data, WCS manages the
cache daemon and cache client. The cache client can be run on either the WAS
machine or the web server machine. Running the WCS cache client on the web
server provides the advantages of serving requests for the cached files faster
and consuming less system resource. The following instruction shows how to set
up a Web server cache client on the web server machine.
Do the following steps to set up the cache daemon so that requests are made
directly from a Web server cache client on your Web server machine to a cache
daemon running on your WebSphere Application Server machine.
1. Launch WCS Configuration Manager, and check whether the cache has been
enabled as described in Section 3.1.1, “Enabling Cache” on page 30.
2. Change the Cleanup Agent Hostname to the remote Web server hostname
(Figure 3-8 on page 42).
Note: Setting up the Web server cache is only necessary if one or more of
your cacheable Web addresses are session independent. If all of your
cacheable Web addresses are session dependent, skip this section.
For NT, refer to
42 WCS V5.1 Performance Tuning
Figure 3-8 Adjusting cache manager for 3-tier configuration
3. Specify your WebSphere Application Server machine in the Cache daemon
port address field.
4. Click Advanced. Deselect the check boxes under Session Dependent
– Store Catalog Display
– Top Categories Display
– Category Display
– Product Display
Click Apply (Figure 3-9 on page 43).
Chapter 3. Tuning WCS instance 43
Figure 3-9 Disabling session-dependent cache
5. Copy the wcs_instances file in the <WCS_install_path>/instances directory of
the WAS machine to the web server machine. You need to manually create a
<WCS_install_path>/instances directory on the web server machine.
6. Copy the <instance_name>.xml file from the
<WCS_install_path>/instances/<instance_name>/xml directory of the WAS
machine to the same path on your remote web server machine. Note that you
may need to create this directory on the web server machine.
7. Copy the following files from the<WCS_install_path>/bin directory on the
WAS machine to the same directory on the web server machine. You may
need to create this directory on the web server machine.
8. Create soft links from the /usr/lib directory to these files as follows:
# ln -s <WCS_install_path>/bin/lib51cache.a /usr/lib/lib51cache.a
# ln -s <WCS_install_path>/bin/libicu-uc.a /usr/lib/libicu-uc.a
# ln -s <WCS_install_path>/bin/libicudata.a /usr/lib/libicudata.a
# ln -s <WCS_install_path>/bin/libxerces-c1_3.a /usr/lib/libxerces-c1_3.a