org.apache.ignite.configuration

Class MemoryPolicyConfiguration

java.lang.Object

org.apache.ignite.configuration.MemoryPolicyConfiguration

All Implemented Interfaces:

Serializable

public final class MemoryPolicyConfiguration
extends Object
implements Serializable

This class allows defining custom memory policies' configurations with various parameters for Apache Ignite page memory (see MemoryConfiguration. For each configured memory policy Apache Ignite instantiates respective memory regions with different parameters like maximum size, eviction policy, swapping options, etc. An Apache Ignite cache can be mapped to a particular policy using CacheConfiguration.setMemoryPolicyName(String) method.

Sample configuration below shows how to configure several memory policies:

     <property name="memoryConfiguration">
         <bean class="org.apache.ignite.configuration.MemoryConfiguration">
             <property name="defaultMemoryPolicyName" value="Default_Region"/>
             <property name="pageSize" value="4096"/>

             <property name="memoryPolicies">
                 <list>
                      <bean class="org.apache.ignite.configuration.MemoryPolicyConfiguration">
                          <property name="name" value="Default_Region"/>
                          <property name="initialSize" value="#{100 * 1024 * 1024}"/>
                      </bean>

                      <bean class="org.apache.ignite.configuration.MemoryPolicyConfiguration">
                          <property name="name" value="20MB_Region_Eviction"/>
                          <property name="initialSize" value="#{20 * 1024 * 1024}"/>
                          <property name="pageEvictionMode" value="RANDOM_2_LRU"/>
                      </bean>

                      <bean class="org.apache.ignite.configuration.MemoryPolicyConfiguration">
                          <property name="name" value="25MB_Region_Swapping"/>
                          <property name="initialSize" value="#{25 * 1024 * 1024}"/>
                          <property name="initialSize" value="#{100 * 1024 * 1024}"/>
                          <property name="swapFilePath" value="memoryPolicyExampleSwap"/>
                      </bean>
                  </list>
              </property>
     
 

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static boolean	DFLT_METRICS_ENABLED Default metrics enabled flag.

Constructor Summary

Constructors

Constructor and Description
MemoryPolicyConfiguration()

Method Summary

Methods

Modifier and Type	Method and Description
int	getEmptyPagesPoolSize() Specifies the minimal number of empty pages to be present in reuse lists for this memory policy.
double	getEvictionThreshold() Gets a threshold for memory pages eviction initiation.
long	getInitialSize() Gets initial memory region size defined by this memory policy.
long	getMaxSize() Maximum memory region size defined by this memory policy.
String	getName() Gets memory policy name.
DataPageEvictionMode	getPageEvictionMode() Gets memory pages eviction mode.
String	getSwapFilePath() A path to the memory-mapped files the memory region defined by this memory policy will be mapped to.
boolean	isMetricsEnabled() Gets whether memory metrics are enabled by default on node startup.
MemoryPolicyConfiguration	setEmptyPagesPoolSize(int emptyPagesPoolSize) Specifies the minimal number of empty pages to be present in reuse lists for this memory policy.
MemoryPolicyConfiguration	setEvictionThreshold(double evictionThreshold) Sets memory pages eviction threshold.
MemoryPolicyConfiguration	setInitialSize(long initialSize) Sets initial memory region size defined by this memory policy.
MemoryPolicyConfiguration	setMaxSize(long maxSize) Sets maximum memory region size defined by this memory policy.
MemoryPolicyConfiguration	setMetricsEnabled(boolean metricsEnabled) Sets memory metrics enabled flag.
MemoryPolicyConfiguration	setName(String name) Sets memory policy name.
MemoryPolicyConfiguration	setPageEvictionMode(DataPageEvictionMode evictionMode) Sets memory pages eviction mode.
MemoryPolicyConfiguration	setSwapFilePath(String swapFilePath) Sets a path to the memory-mapped file.

Methods inherited from class java.lang.Object

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

Field Detail

DFLT_METRICS_ENABLED

public static final boolean DFLT_METRICS_ENABLED

Default metrics enabled flag.

See Also:

Constant Field Values

Constructor Detail

MemoryPolicyConfiguration

public MemoryPolicyConfiguration()

Method Detail

getName

public String getName()

Gets memory policy name.

Returns:

Memory policy name.

setName

public MemoryPolicyConfiguration setName(String name)

Sets memory policy name. The name must be non empty and must not be equal to the reserved 'sysMemPlc' one. If not specified, MemoryConfiguration.DFLT_MEM_PLC_DEFAULT_NAME value is used.

Parameters:

name - Memory policy name.

Returns:

this for chaining.

getMaxSize

public long getMaxSize()

Maximum memory region size defined by this memory policy. If the whole data can not fit into the memory region an out of memory exception will be thrown.

Returns:

Size in bytes.

setMaxSize

public MemoryPolicyConfiguration setMaxSize(long maxSize)

Sets maximum memory region size defined by this memory policy. The total size should not be less than 10 MB due to the internal data structures overhead.

Parameters:

maxSize - Maximum memory policy size in bytes.

Returns:

this for chaining.

getInitialSize

public long getInitialSize()

Gets initial memory region size defined by this memory policy. When the used memory size exceeds this value, new chunks of memory will be allocated.

Returns:

Memory policy start size.

setInitialSize

public MemoryPolicyConfiguration setInitialSize(long initialSize)

Sets initial memory region size defined by this memory policy. When the used memory size exceeds this value, new chunks of memory will be allocated.

Parameters:

initialSize - Memory policy initial size.

Returns:

this for chaining.

getSwapFilePath

public String getSwapFilePath()

A path to the memory-mapped files the memory region defined by this memory policy will be mapped to. Having the path set, allows relying on swapping capabilities of an underlying operating system for the memory region.

Returns:

A path to the memory-mapped files or null if this feature is not used for the memory region defined by this memory policy.

setSwapFilePath

public MemoryPolicyConfiguration setSwapFilePath(String swapFilePath)

Sets a path to the memory-mapped file.

Parameters:

swapFilePath - A Path to the memory mapped file.

Returns:

this for chaining.

getPageEvictionMode

public DataPageEvictionMode getPageEvictionMode()

Gets memory pages eviction mode. If DataPageEvictionMode.DISABLED is used (default) then an out of memory exception will be thrown if the memory region usage, defined by this memory policy, goes beyond its capacity which is getMaxSize().

Returns:

Memory pages eviction algorithm. DataPageEvictionMode.DISABLED used by default.

setPageEvictionMode

public MemoryPolicyConfiguration setPageEvictionMode(DataPageEvictionMode evictionMode)

Sets memory pages eviction mode.

Parameters:

evictionMode - Eviction mode.

Returns:

this for chaining.

getEvictionThreshold

public double getEvictionThreshold()

Gets a threshold for memory pages eviction initiation. For instance, if the threshold is 0.9 it means that the page memory will start the eviction only after 90% of the memory region (defined by this policy) is occupied.

Returns:

Memory pages eviction threshold.

setEvictionThreshold

public MemoryPolicyConfiguration setEvictionThreshold(double evictionThreshold)

Sets memory pages eviction threshold.

Parameters:

evictionThreshold - Eviction threshold.

Returns:

this for chaining.

getEmptyPagesPoolSize

public int getEmptyPagesPoolSize()

Specifies the minimal number of empty pages to be present in reuse lists for this memory policy. This parameter ensures that Ignite will be able to successfully evict old data entries when the size of (key, value) pair is slightly larger than page size / 2. Increase this parameter if cache can contain very big entries (total size of pages in this pool should be enough to contain largest cache entry). Increase this parameter if IgniteOutOfMemoryException occurred with enabled page eviction.

Returns:

Minimum number of empty pages in reuse list.

setEmptyPagesPoolSize

public MemoryPolicyConfiguration setEmptyPagesPoolSize(int emptyPagesPoolSize)

Specifies the minimal number of empty pages to be present in reuse lists for this memory policy. This parameter ensures that Ignite will be able to successfully evict old data entries when the size of (key, value) pair is slightly larger than page size / 2. Increase this parameter if cache can contain very big entries (total size of pages in this pool should be enough to contain largest cache entry). Increase this parameter if IgniteOutOfMemoryException occurred with enabled page eviction.

Parameters:

emptyPagesPoolSize - Empty pages pool size.

Returns:

this for chaining.

isMetricsEnabled

public boolean isMetricsEnabled()

Gets whether memory metrics are enabled by default on node startup. Memory metrics can be enabled and disabled at runtime via memory metrics MX bean.

Returns:

Metrics enabled flag.

setMetricsEnabled

public MemoryPolicyConfiguration setMetricsEnabled(boolean metricsEnabled)

Sets memory metrics enabled flag. If this flag is true, metrics will be enabled on node startup. Memory metrics can be enabled and disabled at runtime via memory metrics MX bean.

Parameters:

metricsEnabled - Metrics enabled flag.

Returns:

this for chaining.