此内容没有您所选择的语言版本。

3.3. Using Eviction

In Red Hat JBoss Data Grid, eviction is disabled by default. If an empty <eviction /> element is used to enable eviction without any strategy or maximum entries settings, the following default values are automatically implemented:

Strategy: If no eviction strategy is specified, EvictionStrategy.NONE is assumed as a default.
max-entries/maxEntries: If no value is specified, the max-entries/maxEntries value is set to -1, which allows unlimited entries.

Report a bug

3.3.1. Initialize Eviction
复制链接

To initialize eviction, set the eviction element's max-entries attributes value to a number greater than zero. Adjust the value set for max-entries to discover the optimal value for your configuration. It is important to remember that if too large a value is set for max-entries, Red Hat JBoss Data Grid runs out of memory.

The following procedure outlines the steps to initialize eviction in JBoss Data Grid:

Procedure 3.1. Initialize Eviction

Add the Eviction Tag
Add the <eviction> tag to your project's <cache> tags as follows:
```
<eviction />
```
```
<eviction />
```
Copy to Clipboard Toggle word wrap
Set the Eviction Strategy
Set the strategy value to set the eviction strategy employed. Possible values are LRU, UNORDERED and LIRS (or NONE if no eviction is required). The following is an example of this step:
```
<eviction strategy="LRU" />
```
```
<eviction strategy="LRU" />
```
Copy to Clipboard Toggle word wrap
Set the Maximum Entries
Set the maximum number of entries allowed in memory. The default value is -1 for unlimited entries.
1. In Library mode, set the maxEntries parameter as follows:
```
<eviction strategy="LRU" maxEntries="200" />
```
```
<eviction strategy="LRU" maxEntries="200" />
```
  Copy to Clipboard Toggle word wrap
2. In Remote Client Server mode, set the max-entries as follows:
```
<eviction strategy="LRU" max-entries="200" />
```
```
<eviction strategy="LRU" max-entries="200" />
```
  Copy to Clipboard Toggle word wrap

Result

Eviction is configured for the target cache.

Report a bug

3.3.2. Eviction Configuration Examples
复制链接

Configure eviction in Red Hat JBoss Data Grid using the configuration bean or the XML file. Eviction configuration is done on a per-cache basis.

A sample XML configuration for Library mode is as follows:
```
<eviction strategy="LRU" maxEntries="2000"/>
```
```
<eviction strategy="LRU" maxEntries="2000"/>
```
Copy to Clipboard Toggle word wrap
A sample XML configuration for Remote Client Server Mode is as follows:
```
<eviction strategy="LRU" max-entries="20"/>
```
```
<eviction strategy="LRU" max-entries="20"/>
```
Copy to Clipboard Toggle word wrap

A sample programmatic configuration for Library Mode is as follows:

Configuration c = new ConfigurationBuilder().eviction().strategy(EvictionStrategy.LRU)
              .maxEntries(2000)
              .build();

Configuration c = new ConfigurationBuilder().eviction().strategy(EvictionStrategy.LRU)
              .maxEntries(2000)
              .build();

Copy to Clipboard

Toggle word wrap

Note

JBoss Data Grid's Library mode uses the maxEntries parameter while Remote Client-Server mode uses the max-entries parameter to configure eviction.

Report a bug

3.3.3. Changing the Maximum Entries Value at Runtime
复制链接

The max-entries value for eviction can be configured for a clustered cache without restarting the server. This configuration is performed on each node in the cluster.

To change the max-entries value in the eviction configuration, perform these steps:

In the cache JMX entry, invoke the setMaxEntries operation.

Invoking the setMaxEntries operation sets maximum number of entries in the data container.
If the data container does not support eviction, setting it will raise an exception.
Defining a value less than 0 will throw an error.

Report a bug

3.3.4. Eviction Configuration Troubleshooting
复制链接

In Red Hat JBoss Data Grid, the size of a cache can be larger than the value specified for the max-entries parameter of the eviction element. This is because although the max-entries value can be configured to a value that is not a power of two, the underlying algorithm will alter the value to V, where V is the closest power of two value that is larger than the max-entries value. Eviction algorithms are in place to ensure that the size of the cache container will never exceed the value V.

Report a bug

3.3.5. Eviction and Passivation
复制链接

To ensure that a single copy of an entry remains, either in memory or in a cache store, use passivation in conjunction with eviction.

The primary reason to use passivation instead of a normal cache store is that updating entries require less resources when passivation is in use. This is because passivation does not require an update to the cache store.

23149%2C+Administration+and+Configuration+Guide-6.628-06-2017+13%3A51%3A02JBoss+Data+Grid+6Documentation6.6.1Report a bug

返回顶部

此内容没有您所选择的语言版本。

3.3. Using Eviction

3.3.1. Initialize Eviction
复制链接

3.3.2. Eviction Configuration Examples
复制链接

3.3.3. Changing the Maximum Entries Value at Runtime
复制链接

3.3.4. Eviction Configuration Troubleshooting
复制链接

3.3.5. Eviction and Passivation
复制链接

学习

尝试、购买和销售

社区

关于红帽文档

让开源更具包容性

關於紅帽

Theme

Red Hat legal and privacy links

Red Hat legal and privacy links

此内容没有您所选择的语言版本。

3.3. Using Eviction

3.3.1. Initialize Eviction复制链接链接已复制到粘贴板!

3.3.2. Eviction Configuration Examples复制链接链接已复制到粘贴板!

3.3.3. Changing the Maximum Entries Value at Runtime复制链接链接已复制到粘贴板!

3.3.4. Eviction Configuration Troubleshooting复制链接链接已复制到粘贴板!

3.3.5. Eviction and Passivation复制链接链接已复制到粘贴板!

学习

尝试、购买和销售

社区

关于红帽文档

让开源更具包容性

關於紅帽

Theme

Red Hat legal and privacy links

Red Hat legal and privacy links

3.3.1. Initialize Eviction
复制链接

3.3.2. Eviction Configuration Examples
复制链接

3.3.3. Changing the Maximum Entries Value at Runtime
复制链接

3.3.4. Eviction Configuration Troubleshooting
复制链接

3.3.5. Eviction and Passivation
复制链接