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Overview

This chapter explains how you can set cache configuration parameters. Once a cache is created, you cannot change its configuration parameters.

Note

Caches vs. Tables in Ignite

The cache-driven configuration approach is one of the configuration options. You can also configure caches/tables using standard SQL commands such as CREATE TABLE. Refer to the Caches vs. Tables section to know the relation between caches and tables in Ignite.

Configuration Example

Below is an example of a cache configuration.

<bean class="org.apache.ignite.configuration.IgniteConfiguration">
    <property name="cacheConfiguration">
        <bean class="org.apache.ignite.configuration.CacheConfiguration">
            <property name="name" value="myCache"/>
            <property name="cacheMode" value="PARTITIONED"/>
            <property name="backups" value="2"/>
            <property name="rebalanceMode" value="SYNC"/>
            <property name="writeSynchronizationMode" value="FULL_SYNC"/>
            <property name="partitionLossPolicy" value="READ_ONLY_SAFE"/>
            <!-- Other parameters -->
        </bean>
    </property>
</bean>

For the full list of parameters, refer to the CacheConfiguration javadoc.

Parameter Description Default Value

name

The cache name.

None.

cacheMode

The cacheMode parameter defines the way data is distributed in the cluster.

In the PARTITIONED mode (default), the overall data set is divided into partitions and all partitions are split between participating nodes in a balanced manner.

In the REPLICATED mode, all the data is replicated to every node in the cluster.

See the Partitioned/Replicated Mode section for more details.

PARTITIONED

writeSynchronizationMode

Write synchronization mode. Refer to the Configuring Partition Backups section.

PRIMARY_SYNC

rebalanceMode

This parameter controls the way the rebalancing process is performed. Possible values include:

  • SYNC — Any requests to the cache’s API are blocked until rebalancing is completed.

  • ASYNC (default) — Rebalancing is performed in the background.

  • NONE — Rebalancing is not triggered.

ASYNC

backups

The number of backup partitions for the cache.

0

partitionLossPolicy

Partition loss policy.

IGNORE

readFromBackup

Read requested cache entry from the backup partition if it is available on the local node instead of making a request to the primary partition (which can be located on the remote nodes).

true

queryPrallelism

The number of threads in a single node to process a SQL query executed on the cache. Refer to the Query Parallelism section in the Performance guide for more information.

1

CacheConfiguration cacheCfg = new CacheConfiguration("myCache");

cacheCfg.setCacheMode(CacheMode.PARTITIONED);
cacheCfg.setBackups(2);
cacheCfg.setRebalanceMode(CacheRebalanceMode.SYNC);
cacheCfg.setWriteSynchronizationMode(CacheWriteSynchronizationMode.FULL_SYNC);
cacheCfg.setPartitionLossPolicy(PartitionLossPolicy.READ_ONLY_SAFE);

IgniteConfiguration cfg = new IgniteConfiguration();
cfg.setCacheConfiguration(cacheCfg);

// Start a node.
Ignition.start(cfg);

For the full list of parameters, refer to the CacheConfiguration javadoc.

Parameter Description Default Value

name

The cache name.

None.

cacheMode

The cacheMode parameter defines the way data is distributed in the cluster.

In the PARTITIONED mode (default), the overall data set is divided into partitions and all partitions are split between participating nodes in a balanced manner.

In the REPLICATED mode, all the data is replicated to every node in the cluster.

See the Partitioned/Replicated Mode section for more details.

PARTITIONED

writeSynchronizationMode

Write synchronization mode. Refer to the Configuring Partition Backups section.

PRIMARY_SYNC

rebalanceMode

This parameter controls the way the rebalancing process is performed. Possible values include:

  • SYNC — Any requests to the cache’s API are blocked until rebalancing is completed.

  • ASYNC (default) — Rebalancing is performed in the background.

  • NONE — Rebalancing is not triggered.

ASYNC

backups

The number of backup partitions for the cache.

0

partitionLossPolicy

Partition loss policy.

IGNORE

readFromBackup

Read requested cache entry from the backup partition if it is available on the local node instead of making a request to the primary partition (which can be located on the remote nodes).

true

queryPrallelism

The number of threads in a single node to process a SQL query executed on the cache. Refer to the Query Parallelism section in the Performance guide for more information.

1

var cfg = new IgniteConfiguration
{
    CacheConfiguration = new[]
    {
        new CacheConfiguration
        {
            Name = "myCache",
            CacheMode = CacheMode.Partitioned,
            Backups = 2,
            RebalanceMode = CacheRebalanceMode.Sync,
            WriteSynchronizationMode = CacheWriteSynchronizationMode.FullSync,
            PartitionLossPolicy = PartitionLossPolicy.ReadOnlySafe
        }
    }
};
Ignition.Start(cfg);
CREATE TABLE IF NOT EXISTS Person (
  id int,
  city_id int,
  name varchar,
  age int,
  company varchar,
  PRIMARY KEY (id, city_id)
) WITH "cache_name=myCache,template=partitioned,backups=2";

For the full list of parameters, refer to the CREATE TABLE section.

This API is not presently available for C++. You can use XML configuration.

Cache Templates

A cache template is an instance of CacheConfiguration that can be registered in the cluster and used later as a basis for creating new caches or SQL tables. A cache or table created from a template inherits all the properties of the template.

Templates are useful when creating a table using the CREATE TABLE command, because the command does not support all available cache parameters.

Note
Currently, templates are supported for the CREATE TABLE and REST commands.

To create a template, define a cache configuration and add it to the Ignite instance, as shown below. If you want do define a cache template in the XML configuration file, you must add an asterisk to the template’s name. This is required to indicate that the configuration is a template and not an actual cache.

<bean class="org.apache.ignite.configuration.IgniteConfiguration">
    <property name="cacheConfiguration">
        <list>
            <bean abstract="true" class="org.apache.ignite.configuration.CacheConfiguration" id="cache-template-bean">
                <!-- when you create a template via XML configuration, you must add an asterisk to the name of the template -->
                <property name="name" value="myCacheTemplate*"/>
                <property name="cacheMode" value="PARTITIONED"/>
                <property name="backups" value="2"/>
                <!-- Other cache parameters -->
            </bean>
        </list>
    </property>
</bean>
IgniteConfiguration igniteCfg = new IgniteConfiguration();

try (Ignite ignite = Ignition.start(igniteCfg)) {
    CacheConfiguration cacheCfg = new CacheConfiguration("myCacheTemplate");

    cacheCfg.setBackups(2);
    cacheCfg.setCacheMode(CacheMode.PARTITIONED);

    // Register the cache template
    ignite.addCacheConfiguration(cacheCfg);
}
var ignite = Ignition.Start();

var cfg = new CacheConfiguration
{
    Name = "myCacheTemplate*",
    CacheMode = CacheMode.Partitioned,
    Backups = 2
};

ignite.AddCacheConfiguration(cfg);
This API is not presently available for C++. You can use XML configuration.

Once the cache template is registered in the cluster, as shown in the code snippet above, you can use it to create another cache with the same configuration.