Package com.microstrategy.webapi

Class MSIRefreshClusterMembershipCache

java.lang.Object

com.microstrategy.utils.cache.CacheBase

com.microstrategy.webapi.MSIRefreshClusterMembershipCache

All Implemented Interfaces:

Cache

public final class MSIRefreshClusterMembershipCache
extends CacheBase

MSIGetClusterMembershipCache uses the CacheBase infrastructure to manage the calls to RefreshClusterMembership. RefreshClusterMembership is a heavy call to IServer because when called against an IServer, it makes calls to all other IServers in the cluster to get the project information before returning.
MSIGetClusterMembershipCache will cache the results of RefreshClusterMembership for a period of time in the order of 5-10 seconds. Any calls to RefreshClusterMembership before the cache expires will hit the cache and NOT make a call to an IServer. Any calls after the cache has expired will call RefreshClusterMembership on the IServer.

This paradigm is "eventual consistency"; we are allowed to use old information as long as the old information isn't too old.

This optimization allows disparate parts of the code-base to be free to call RefreshClusterMembership when needed.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	MSIRefreshClusterMembershipCache.RCMKey	RCMKey is the key to the getClusterMembership cache.

Field Summary

Fields inherited from class com.microstrategy.utils.cache.CacheBase

alias, DEFAULT_FILE_REFRESH_TIME, DEFAULT_REFRESH_TIME, DEFAULT_STATISTIC_TIME, DEFAULT_SYS_TIMEOUT, DEFAULT_USER_TIMEOUT, NO_KEY, NO_REFRESH, NO_STATISTIC, NO_TIMEOUT

Method Summary

Modifier and Type	Method	Description
static MSIRefreshClusterMembershipCache	getInstance()
protected java.lang.Object	getKey(CacheHint iKey)	Overridable.
protected java.util.Collection<com.microstrategy.webapi.ClusterMemberInfo>	load(CacheHint iKey)	Overridable.

Methods inherited from class com.microstrategy.utils.cache.CacheBase

canUpdate, clear, close, configure, contains, delete, get, getName, getRefreshTime, getStatisticTime, getTimeout, getWithoutRefresh, logStatistic, onHintClose, onTimer, put, refresh, reLoad, remove, save, setRefreshTime, setStatisticTime, setTimeout, size, store, unLoad

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

getInstance

public static MSIRefreshClusterMembershipCache getInstance()

getKey

protected java.lang.Object getKey(CacheHint iKey)
                           throws CacheException

Description copied from class: CacheBase

Overridable. Extracts from the hint object the key that shall be used to identify the cached object.

Specified by:

getKey in class CacheBase

Parameters:

iKey - the hint object.

Returns:

the key

Throws:

CacheException - if somethig gos wrong.

load

protected java.util.Collection<com.microstrategy.webapi.ClusterMemberInfo> load(CacheHint iKey)
                                                                         throws CacheException

Description copied from class: CacheBase

Overridable. Creates a new cached object instance and populates it with data from the persistent storage. In case the object not found in the persistent storage the implementation can return either null or a dummy object.

Specified by:

load in class CacheBase

Parameters:

iKey - the hint object.

Returns:

the object or null.

Throws:

CacheException - if somethig gos wrong.