IBM WEBSPHERE 6.1.X Manual de usuario descargar pdf (Pagina 66)

WE BSPHERE PORTAL V6.1 TUNING GUIDE

Cache Usage Patterns

Most WebSphere Portal caches follow the simple paradigm: if an entry already exists use it,

otherwise add the entry. However, there are caches that behave differently. Each cache

follows one of the following four patterns:

 Pattern: regular

The regular pattern, described earlier, is the most common cache pattern:

value = cache.get(key);

if (value == null) {

value = calculateNewValue();

cache.put(key, value);

}

 Pattern: invalidation checking

Invalidating cache entries in a clustered environment is rather expensive. Therefore, portal caches often check whether the entry to be

invalidated actually exists in the local cache.

test = cache.get(key);

if (test != null) {

cache.invalidate(key);

}

Caches following this pattern follow the regular pattern for all but invalidation

actions.

 Pattern: multiple object types

Most caches hold only a single object type. When caches can hold multiple types,

they follow the regular pattern for each of those types.

 Pattern: cascading object types

This pattern is a special case of the ‘multiple object types’ pattern in that two or more object types that are queried in a certain order are

stored in a single cache. There may be one cache hit along with a cache miss on a regular basis.

value = cache.get(keyA);

if (value == null) {

value = cache.get(keyB);

if (value == null) {

value = calculateNewValue();

cache.put(keyA || keyB, value); // either key could be used

}

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ChrisCaddy 27 Apr 2024 | 05:14:13

Hello, im noob :)

IBM WEBSPHERE 6.1.X Manual de usuario Pagina 66