By default, the Tomcat module will run Tanzu GemFire automatically with pre-configured settings. You can change these Tanzu GemFire settings.
Here are the default settings:
- Locators are used for member discovery.
- The region name is set to
gemfire_modules_sessions. - The cache region is replicated for peer-to-peer configurations and partitioned (with redundancy turned on) for client/server configurations.
- Tanzu GemFire clients have local caching turned on and when the local cache needs to evict data, it will evict least-recently-used (LRU) data first.
Note: On the application server side, the default inactive interval for session expiration is set to 30 minutes. For information about changing this value, see Session Expiration in General Information on HTTP Session Management.
Changing Tanzu GemFire Distributed System Properties
Tanzu GemFire system properties must be set by adding properties to Tomcat’s server.xml file. When setting properties, use the following syntax:
<Listener
className="org.apache.geode.modules.session.catalina.xxxLifecycleListener"
property-name="property-value"
property-name="property-value"
...
/>
Where:
property-nameis the name of a property.property-valueis value of that property.
If the xxxLifecycleListener is a PeerToPeerCacheLifecycleListener, then a minimal addition to the server.xml file is the following:
<Listener
className="org.apache.geode.modules.session.catalina.
PeerToPeerCacheLifecycleListener"
cache-xml-file="cache-peer.xml"
locators="localhost[10334]"
/>
The list of Tomcat’s configurable server.xml system properties includes any of the properties that can be specified in Tanzu GemFire’s gemfire.properties file. The following list contains some of the properties that can be configured.
| Property | Description | Default |
|---|---|---|
| cache-xml-file | Name of the cache configuration file | cache-peer.xml for peer-to-peer, cache-client.xml for client/server |
| locators (only for peer-to-peer topology) | Required: A list of locators in (host\[port\]) format used by Tanzu GemFire members. If a single locator listens on its default port, set this value to "localhost[10334]" |
Empty string |
| log-file | Name of the Tanzu GemFire log file | gemfire_modules.log |
| statistic-archive-file | Name of the Tanzu GemFire statistics file | gemfire_modules.gfs |
| statistic-sampling-enabled | Whether Tanzu GemFire statistics sampling is enabled | false |
For more information about these properties, along with the full list of properties, see Reference.
In addition to the standard Tanzu GemFire system properties, the following cache-specific properties can also be configured with the LifecycleListener.
| Property | Description | Default |
|---|---|---|
| criticalHeapPercentage | Percentage of heap at which updates to the cache are refused | 0 (Deactivated) |
| evictionHeapPercentage | Percentage of heap at which session eviction begins | 80.0 |
| rebalance | Whether a rebalance of the cache should be done when the application server instance is started | false |
Although these properties are not part of the standard Tanzu GemFire system properties, they apply to the entire JVM instance and are therefore also handled by the LifecycleListener. For more information about managing the heap, see Controlling Heap Use with the Resource Manager in Managing Heap Memory.
Changing Cache Configuration Properties
To edit Tanzu GemFire cache properties such as the name and the characteristics of the cache region, add these properties to Tomcat’s context.xml file. When adding properties, unless otherwise specified, use the following syntax:
<Manager
className="org.apache.geode.modules.session.catalina.Tomcat9DeltaSessionManager"
property-name="property-value"
property-name="property-value"
...
/>
Where:
property-nameis the name of a property.property-valueis the value of that property.
For example, this entry creates a partitioned region with the name my_region.
<Manager className="org.apache.geode.modules.session.catalina.
Tomcat9DeltaSessionManager"
regionAttributesId="PARTITION_REDUNDANT"
regionName="my_region"
/>
The following parameters are the cache configuration parameters that can be added to Tomcat’s context.xml file.
context.xml file, then only one put will be performed into the cache for the session per HTTP request. If the configuration line is not included, then the session is saved each time the
setAttribute or
removeAttribute method is invoked. As a consequence, multiple puts are performed into the cache during a single session. This configuration setting is recommended for any applications that modify the session frequently during a single HTTP request.
Default: Set
To deactivate this configuration, remove or comment out the following line from Tomcat’s context.xml file.
<Valve className="org.apache.geode.modules.session.catalina.CommitSessionValve"/>
Default: false
The Tanzu GemFire API equivalent to setting this parameter:
// Create factory
AttributesFactory factory = ...; <or> RegionFactory factory = ...;
// Add cache listener
factory.addCacheListener(new DebugCacheListener());
Default: true for client/server. enableLocalCache is only useful with a client/server topology.
The Tanzu GemFire API equivalent to setting this parameter:
ClientCache.createClientRegionFactory(CACHING_PROXY_HEAP_LRU);
PARTITION_REDUNDANT instead of
PARTITION to ensure that the failure of a server does not result in lost session data.
Default: REPLICATE for peer-to-peer, PARTITION_REDUNDANT for client/server
The Tanzu GemFire API equivalent to setting this parameter:
// Creates a region factory for the specified region shortcut
Cache.createRegionFactory(regionAttributesId);
Default: gemfire_modules_sessions
The Tanzu GemFire API equivalent to setting this parameter:
// Creates a region with the specified name
RegionFactory.create(regionName);
