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23.9. Other Management Tools and Operations
23.9.1. Accessing Data via URLs
put() and post() methods place data in the cache, and the URL used determines the cache name and key(s) used. The data is the value placed into the cache, and is placed in the body of the request.
GET and HEAD methods are used for data retrieval while other headers control cache settings and behavior.
Note
23.9.2. Limitations of Map Methods
size(), values(), keySet() and entrySet(), can be used with certain limitations with Red Hat JBoss Data Grid as they are unreliable. These methods do not acquire locks (global or local) and concurrent modification, additions and removals are excluded from consideration in these calls.
In JBoss Data Grid 7.0 the map methods size(), values(), keySet(), and entrySet() include entries in the cache loader by default. The cache loader in use will determine the performance of these commands; for instance, when using a database these methods will run a complete scan of the table where data is stored, which may result in slower processing. To not load entries from the cache loader, and avoid any potential performance hit, use Cache.getAdvancedCache().withFlags(Flag.SKIP_CACHE_LOAD) before executing the desired method.
In JBoss Data Grid 7.0 the Cache.size() method provides a count of all elements in both this cache and cache loader across the entire cluster. When using a loader or remote entries, only a subset of entries is held in memory at any given time to prevent possible memory issues, and the loading of all entries may be slow.
size() method is affected by the flags org.infinispan.context.Flag#CACHE_MODE_LOCAL, to force it to return the number of entries present on the local node, and org.infinispan.context.Flag#SKIP_CACHE_LOAD, to ignore any passivated entries. Either of these flags may be used to increase performance of this method, at the cost of not returning a count of all elements across the entire cluster.
In JBoss Data Grid 7.0 the Hot Rod protocol contain a dedicated SIZE operation, and the clients use this operation to calculate the size of all entries.
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