This page describes an older version of the product. The latest stable version is 12.2.

Filtering Data


In some cases, there can be data that should not be replicated between the sites but should still be replicated locally between the primary and the backup/mirror service. In this case using the replicate class level or object level decoration is irrelevant as there is a need to control the replication behavior only to the remote site. Since a replication channel to a gateway is like any other replication channel, therefore a custom Replication Filter at the source space can be used to filter the relevant data from being sent to the target gateway.

WAN-replicationfilter.jpg

This filtering should be based on the replication target name in order to identify the correct replication filter is called for the outgoing replication to the gateway.

The output-filter can be used also to modify the replicated data before it is arriving the target site. When using a SpaceDocument the modified field must be a predefined field described with the document schema (fixed field).

Using the Filter

Filtering Objects

With the example below a replication filter is used with the source space (output-filter). The New-York space is configured not to replicate the Stock object type to London site. This Stock object type still being replicated to all other location replication targets (backup/mirror) and also to the remote Hong Kong gateway. The filtering can be determined also based on the content of the replicated object or any other custom business logic.

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xmlns:os-core="http://www.openspaces.org/schema/core"
    xmlns:os-events="http://www.openspaces.org/schema/events"
    xmlns:os-remoting="http://www.openspaces.org/schema/remoting"
    xmlns:os-sla="http://www.openspaces.org/schema/sla"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.1.xsd
       http://www.openspaces.org/schema/core http://www.openspaces.org/schema/12.0/core/openspaces-core.xsd
       http://www.openspaces.org/schema/events http://www.openspaces.org/schema/12.0/events/openspaces-events.xsd
       http://www.openspaces.org/schema/remoting http://www.openspaces.org/schema/12.0/remoting/openspaces-remoting.xsd
       http://www.openspaces.org/schema/sla http://www.openspaces.org/schema/12.0/sla/openspaces-sla.xsd
       http://www.openspaces.org/schema/core/gateway http://www.openspaces.org/schema/12.0/core/gateway/openspaces-gateway.xsd">

        <bean id="londonFilter" class="com.gigaspaces.examples.gateway.LondonReplicationFilter"/>

        <os-core:embedded-space id="space" name="myNYSpace" gateway-targets="gatewayTargets">
          <os-core:space-replication-filter>
            <os-core:output-filter ref="londonFilter"/>
          </os-core:space-replication-filter>
        </os-core:embedded-space>

        <os-gateway:targets id="gatewayTargets" local-gateway-name="NEWYORK">
          <os-gateway:target name="LONDON"/>
          <os-gateway:target name="HONGKONG"/>
        </os-gateway:targets>

</beans>
public class LondonReplicationFilter implements IReplicationFilter {

  public void init(IJSpace space, String paramUrl, ReplicationPolicy replicationPolicy) {
  }

  public void process(int direction, IReplicationFilterEntry replicationFilterEntry, String replicationTargetName) {
      if (replicationTargetName.equals("gateway:LONDON")) {
          if (replicationFilterEntry.getClassName().equals(Stock.class.getName())) {
              replicationFilterEntry.discard();
          }
      }
  }

  public void close() {
  }
}

Filtering Space Events

You can choose which Space events (Take, Lease Expiration etc) are replicated. In the example below we define a filter that prevents the DISCARD and LEASE_EXPIRATION events to be replicated:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
    xmlns:os-core="http://www.openspaces.org/schema/core" xmlns:os-events="http://www.openspaces.org/schema/events"
    xmlns:tx="http://www.springframework.org/schema/tx" xmlns:os-remoting="http://www.openspaces.org/schema/remoting"
    xmlns:os-gateway="http://www.openspaces.org/schema/core/gateway"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.1.xsd
       http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.1.xsd
       http://www.openspaces.org/schema/core http://www.openspaces.org/schema/12.0/core/openspaces-core.xsd
       http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.1.xsd
       http://www.openspaces.org/schema/events http://www.openspaces.org/schema/events/openspaces-events.xsd
       http://www.openspaces.org/schema/core/gateway http://www.openspaces.org/schema/12.0/core/gateway/openspaces-gateway.xsd
       http://www.openspaces.org/schema/remoting http://www.openspaces.org/schema/remoting/openspaces-remoting.xsd">

    <context:component-scan base-package="com.gigaspaces.demo" />

    <!-- Enables the usage of @GigaSpaceContext annotation based injection. -->
    <os-core:giga-space-context />

    <context:annotation-config />
    <!--<tx:annotation-driven transaction-manager="transactionManager" />-->

    <os-core:distributed-tx-manager id="transactionManager" />

    <!-- Enable support for @Polling annotation -->
    <os-events:annotation-support />
   
    <!-- Bean to filter the take operations -->
    <bean id="XPIFilter" class="com.gigaspaces.demo.XPIReplicationFilter"/>

    <os-core:space id="space" url="/./wanSpaceAgency" gateway-targets="gatewayTargets">    
        <os-core:space-replication-filter>
            <os-core:output-filter ref="XPIFilter"/>
        </os-core:space-replication-filter>
    </os-core:space>
 
    <os-core:giga-space id="gigaSpace" space="space" tx-manager="transactionManager" />

    <os-gateway:targets id="gatewayTargets" local-gateway-name="XPI">
        <os-gateway:target name="IE" />
    </os-gateway:targets>
</beans>
package com.gigaspaces.demo;

import com.j_spaces.core.cluster.*;
import com.j_spaces.core.*;

public class XPIReplicationFilter implements IReplicationFilter {
    
    public void init(IJSpace space, String paramUrl, ReplicationPolicy replicationPolicy) {
    }
    
    public void process(int direction, IReplicationFilterEntry replicationFilterEntry, String replicationTargetName) {
      
        switch ( replicationFilterEntry.getOperationType() )
        {
            case TAKE: replicationFilterEntry.discard(); break;
            case DISCARD: replicationFilterEntry.discard(); break;
            case LEASE_EXPIRATION: replicationFilterEntry.discard(); break;
        }
    }
    
    public void close() {
    }
}