Need to execute code before Ignite cache ExpiryPolicy

Question

I am using Ignite cache with ModifiedExpiryPolicy and need to execute a line of code before event execution. Any help?

IgniteCache<String, Object> expiresCache = cache.withExpiryPolicy(new ModifiedExpiryPolicy(new Duration(Time.MINUTES, timeInMins)));

public class ClassName {
public IgnitePredicate<CacheEvent> functionName() {
    return new IgnitePredicate<CacheEvent>() {  
        @Override
        public boolean apply(CacheEvent evt) {
            //code to be executed after event.
            return true;
            }
        };
    }
}

Before or after the event? Your wording and the comments disagree? — Stephen Darlington, Jul 18 '19 at 13:25
@StephenDarlington Before. The after is just executed in the block above , but need to know how to do something just before that — Sarah Tammam, Jul 18 '19 at 13:27
Could you give more details please? What are trying to achieve exactly? — Vladimir Pligin, Jul 18 '19 at 13:29
I need to access the object for database update (adding log) just before it's removed from cache — Sarah Tammam, Jul 18 '19 at 13:32

score 1 · Accepted Answer · answered Jul 19 '19 at 14:51

I think you need to use events to listen for expiry events.

Ignite ignite = Ignition.ignite();

// Local listener that listenes to local events.
IgnitePredicate<CacheEvent> locLsnr = evt -> {
  System.out.println("Received expiry event [evt=" + evt.name() + ", key=" + evt.key());

  return true; // Continue listening.
};

// Subscribe to specified cache events occuring on local node.
ignite.events().localListen(locLsnr, EventType.EVT_CACHE_OBJECT_EXPIRED);

Note that this is just a local (node) listener, you'll need a remote listener to find expiry events on remote nodes. You'll also need to configure includeEventTypes in your configuration file (events are disabled by default for performance reasons.

Need to execute code before Ignite cache ExpiryPolicy

1 Answers1