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Geva makes a strong argument…

August 1st, 2008

In his blog post: here Geva Perry speaks about the dollars and sense regarding setting up shop in a cloud and how GigaSpaces’ Elastic Appserver [my term], provides incredible efficiency which leads to greater dollar value realized from your it investment. After reading Geva’s blog, I have nothing to add except I am *so* glad I work for GigaSpaces!

BTW, These days, I am conducting various educational webinars designed to assist new users in understanding the nature of architecting and programming GigaSpaces solutions. Please, feel free to check them out.

Other news: I created a new introductory video series with a new and improved [or so I think] HelloWorld application example. The videos are < 20 minutes each and should also prove useful in helping users get started with the GigaSpacesXAP way of doing things. Check out this quick start guide to see what I am talking about.

Hope you are having a great summer, my family is back in FL (remember the wedding pics?) so, I should be able to get a tan and lose some weight playing tennis and swimming. -ahh life is good.

Cheers,

Owen.

Can scaling be made seamless?

July 29th, 2008

Putting together the two words “seamless scaling” in front of a technical audience is a very dangerous thing to do. The technically savvy folks are walking around with plenty of scars from previous attempts to scale their system - enough…

TSSJS Prague: my take-aways

June 27th, 2008

Once again TSSJS was a well-organized event with lots of interesting content. Hot topics that I took notice of were RIA, new languages, and obviously distributed computing and scalability. I arrived on Tuesday morning, which gave me a chance to…

Meet us @ TSSJS Prague

June 16th, 2008

TheServerSide has a good record of picking nice spots for their conferences, and this year’s Java Symposium in Prague is no exception. It’s looking to be a fun event, as I’m going to meet not just lots of old friends,…

SyncRemoting cookbook

June 4th, 2008

I wrote up a cheat sheet for myself when building scatter-gather or map reduce apps with GigaSpacesXAP.

It goes like this:

Create business interface (as part of shared classes)

Space-side stuff:

Create the Space-side implementation (logic) [ This may use a GigaSpace reference ]
Configure the implementation on the Space-Side:
Declare the business implementation as a [bean]
Declare a filter as part of the space
The filter references a ServiceExporter
Declare the os-remoting:service-exporter
The exporter references the business implementation [the bean]
If impl uses space: Declare the giga-space-context

Client-side stuff

Declare os-remoting:sync-proxy with its attributes:
The business interface it implements
The giga-space it uses as a transport layer
Whether broadcast is true or false
If necessary –declare the reducer for the proxy
Inject the client with the service proxy (ie: public void setMyService(MyService ref){} )

Let’s say we want to do a Map reduce exercise where each node in the cluster will process its share in parallel and return a total result for my digestion…

Let’s say I want to know the average price for all my widgets in all my inventory, but my inventory is scattered across a dozen servers because I do so much business…

I have my widgets:

package com.test.common;

import com.gigaspaces.annotation.pojo.SpaceRouting;

public class Widget {

private Double price;

private String description;

private Integer routingValue;

public Double getPrice() {
  return price;
}
public void setPrice(Double price) {
  this.price = price;
}
public String getDescription() {
  return description;
}
public void setDescription(String description) {
  this.description = description;
}
@SpaceRouting
public Integer getRoutingValue() {
  return routingValue;
}
public void setRoutingValue(Integer routingValue) {
  this.routingValue = routingValue;
}
}

My Service needs an interface such as:

package com.test.common;
public interface PricingService{

public Double getAveragePriceOfAllWidgets();
}

Next, I need to implement the service:

package com.test;

import org.openspaces.core.GigaSpace;
import org.openspaces.core.context.GigaSpaceContext;
import com.j_spaces.core.client.SQLQuery;
import com.test.common.PricingService;
import com.test.common.Widget;

public class PricingServiceImpl implements PricingService{
@GigaSpaceContext
GigaSpace space;

public Double getAveragePriceOfAllWidgets() {
  Object[] allWidgets = space.readMultiple(new Widget(), Integer.MAX_VALUE);
  double priceTotal = 0.0d;
  for(int x=0;x<allWidgets.length;x++){
   priceTotal=priceTotal+((Widget)allWidgets[x]).getPrice().doubleValue();
  }
  double averagePrice = priceTotal/allWidgets.length;
  return new Double(averagePrice);
}
}

Now I need a client that uses this service:

package com.test;
import java.util.TimerTask;
import com.test.common.PricingService;

public class WidgetSurfingClient extends TimerTask{

private PricingService service;
public void setPricingService(PricingService ref){
this.service=ref;
}
public void run(){
System.out.println(
”The average price of all widgets is now: $”+
service.getAveragePriceOfAllWidgets());
}
}

Now I need something to do the “reduce” side of the map-reduce: (it also performs the final average calculation because I am looking for the average price…

package com.test;
import org.openspaces.remoting.RemoteResultReducer;
import org.openspaces.remoting.SpaceRemotingInvocation;
import org.openspaces.remoting.SpaceRemotingResult;

public class AveragingDoubleResultReducer implements RemoteResultReducer<Double,Double>{

public Double reduce(SpaceRemotingResult<Double>[] results,
SpaceRemotingInvocation remotingInvocation) throws Exception {
  double totalDouble = 0.0d;
  int size = results.length;
  for (int x=0;x<size;x++){
   if(results[x]!=null){
    if(results[x].getResult()!=null){
      totalDouble += (Double) results[x].getResult();
    }
   }
  }
  double averageDouble=totalDouble/size;
  return new Double(averageDouble);
}
}

That takes care of the Java code, now we have to configure this system:

First: the Space-side configuration:

<!– declare the transaction manager –>
<os-core:local-tx-manager id=”transactionManager”
space=”widgetTransport”/>

<bean id=”PricingService” class=”com.test.PricingServiceImpl”/>

<!– provide a gigaspace context to the pricing service –>
<os-core:giga-space-context/>

<!–
Provide the binding to the Space-side
transport for the PricingService :
–>
<os-remoting:service-exporter id=”PricingServiceExporter”>
<os-remoting:service ref=”PricingService”/>
</os-remoting:service-exporter>

<!– configure a big or small cluster
(here we have 20 partitions with 1 backup for each) –>
<os-sla:sla cluster-schema=”partitioned-sync2backup”
number-of-instances=”20″ number-of-backups=”1″
max-instances-per-vm=”1″>
</os-sla:sla>

</beans>

Next: the client-side configuration:

<!– bootstrap the basic proxy for the serviceCluster: –>
<os-core:space id=”widgetTransport” url=”jini://*/*/widgetsystem” />

<!– wrap the proxy in Spring-ready OpenSpaces API –>
<os-core:giga-space id=”gigaspace” space=”widgetTransport” />

<!– WidgetSurfer Service –>
<bean id=”WidgetSurfer” class=”com.test.WidgetSurfingClient”>
<property name=”pricingService” ref=”PricingService”/>
</bean>

<os-remoting:sync-proxy id=”PricingService”
            giga-space=”gigaspace”
            broadcast=”true”
            interface=”com.test.common.PricingService”>
<os-remoting:result-reducer ref=”AveragingDoubleResultReducer”/>
</os-remoting:sync-proxy>

<!– this is regular Spring TimerTask configuration stuff: –>
<bean id=”widgetClientTask” class=”org.springframework.scheduling.timer.ScheduledTimerTask” >
<!– wait 1 seconds before starting repeated execution –>
<property name=”delay” value=”1000″ />
<!– run every 5 seconds –>
<property name=”period” value=”5000″ />
<property name=”timerTask” ref=”WidgetSurfer” />
</bean>

<bean id=”widgetClientTimer” class=”org.springframework.scheduling.timer.TimerFactoryBean”>
   <property name=”scheduledTimerTasks”>
    <list>
      <!– This wires the factory to the scheduledTask bean above –>
      <ref bean=”widgetClientTask” />
    </list>
   </property>
</bean>
</beans>