WebSphere eXtreme Scale Administration Guide > Configure WebSphere eXtreme Scale > Map entry locking

Configure a locking strategy

You can define an optimistic, a pessimistic, or no locking strategy on each BackingMap in the WebSphere eXtreme Scale configuration.

You can specify a locking strategy either:

• programmatically
• with XML

Specify optimistic locking strategy programmatically

import com.ibm.websphere.objectgrid.BackingMap;
import com.ibm.websphere.objectgrid.LockStrategy;
import com.ibm.websphere.objectgrid.ObjectGrid;
import com.ibm.websphere.objectgrid.ObjectGridManagerFactory;
...
ObjectGrid og = 
    ObjectGridManagerFactory.getObjectGridManager().createObjectGrid("test");

BackingMap bm = og.defineMap("optimisticMap");

bm.setLockStrategy( LockStrategy.OPTIMISTIC );

Specify optimistic locking strategy using XML

<?xml version="1.0" encoding="UTF-8"?>

<objectGridConfig 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://ibm.com/ws/objectgrid/config/objectGrid.xsd"
    xmlns="http://ibm.com/ws/objectgrid/config">
   
    <objectGrids>
           
        <objectGrid name="test">
                   
            <backingMap name="optimisticMap"
                        lockStrategy="OPTIMISTIC"/>
       
        </objectGrid>
   
    </objectGrids>
</objectGridConfig>

Specify pessimistic locking strategy programmatically

import com.ibm.websphere.objectgrid.BackingMap;
import com.ibm.websphere.objectgrid.LockStrategy;
import com.ibm.websphere.objectgrid.ObjectGrid;
import com.ibm.websphere.objectgrid.ObjectGridManagerFactory;
...
ObjectGrid og = 
    ObjectGridManagerFactory.getObjectGridManager().createObjectGrid("test");
BackingMap bm = og.defineMap("pessimisticMap");
bm.setLockStrategy( LockStrategy.PESSIMISTIC);

Specify pessimistic locking strategy using XML

<?xml version="1.0" encoding="UTF-8"?>

<objectGridConfig 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://ibm.com/ws/objectgrid/config/objectGrid.xsd"
    xmlns="http://ibm.com/ws/objectgrid/config">

   
    <objectGrids>
       
        <objectGrid name="test">
                   
        <backingMap name="pessimisticMap"
                    lockStrategy="PESSIMISTIC"/>
               
        </objectGrid>
   
    </objectGrids>
</objectGridConfig>

Specify a no-locking strategy programmatically

import com.ibm.websphere.objectgrid.BackingMap;
import com.ibm.websphere.objectgrid.LockStrategy;
import com.ibm.websphere.objectgrid.ObjectGrid;
import com.ibm.websphere.objectgrid.ObjectGridManagerFactory;
...
ObjectGrid og = 
    ObjectGridManagerFactory.getObjectGridManager().createObjectGrid("test");
BackingMap bm = og.defineMap("noLockingMap");
bm.setLockStrategy( LockStrategy.NONE);

Specify a no-locking strategy with XML

<?xml version="1.0" encoding="UTF-8"?>

<objectGridConfig 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://ibm.com/ws/objectgrid/config/objectGrid.xsd"
    xmlns="http://ibm.com/ws/objectgrid/config">

   
<objectGrids>
       
    <objectGrid name="test">
               
        <backingMap name="noLockingMap"
                        lockStrategy="NONE"/>
               
        </objectGrid>
       
    </objectGrids>
</objectGridConfig>

What to do next

To avoid a java.lang.IllegalStateException exception, call the setLockStrategy method before calling the initialize or getSession methods on the ObjectGrid instance.

Parent topic

Map entry locking

Related concepts

WebSphere eXtreme Scale client configuration
Integrate with Spring framework
System APIs and plug-ins
Near cache scenario

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