Q:

Apache Ignite : Continuous Async Query is not working continuous

I am trying to run Continuous Async Query.  On my windows box, I have started Apache Ignite with double click on ignite.bat file and trying to run following code - 
Data Publisher client
package ignite;
import org.apache.ignite. Ignite;
import org.apache.ignite. IgniteCache;
import org.apache.ignite. IgniteDataStreamer;
import org.apache.ignite. Ignition;
import org.apache.ignite.cache. CacheMode;
import org.apache.ignite.configuration. CacheConfiguration;

public class IgniteStreamPublisher {
    public static void main(String[] args) throws Exception {
        System.out.println("Run Spring example!!"); 
        Ignition.setClientMode(true);

        Ignite ignite = Ignition.start();

        CacheConfiguration<Integer, Person> cacheConfiguration = new CacheConfiguration<Integer, Person>("myStreamCache");
        cacheConfiguration.setIndexedTypes(Integer.class, Person.class);
        cacheConfiguration.setCacheMode(CacheMode. PARTITIONED);

        IgniteCache<Integer, Person> cache = ignite.getOrCreateCache(cacheConfiguration);

        IgniteDataStreamer<Integer, Person> stmr = ignite.dataStreamer("myStreamCache");
        stmr.allowOverwrite(true);
        try {
            for (int i = 0; i < 100; i++) {
                Person person = new Person(i, i, "name_" + i, (i * 100) % 3000);
                System.out.println("putting--" + person);
                stmr.addData(i, person);    
                Thread.sleep(1*1000);
                stmr.flush();
            }
        }finally{
            stmr.close();
        }
    }

}

Data Receiver Client
package ignite;

import javax.cache. Cache;
import javax.cache.configuration. Factory;
import javax.cache.event. CacheEntryEvent;
import javax.cache.event. CacheEntryEventFilter;
import javax.cache.event. CacheEntryUpdatedListener;

import org.apache.ignite. Ignite;
import org.apache.ignite. IgniteCache;
import org.apache.ignite. Ignition;
import org.apache.ignite.cache. CacheMode;
import org.apache.ignite.cache.query. ContinuousQuery;
import org.apache.ignite.cache.query. Query;
import org.apache.ignite.cache.query. QueryCursor;
import org.apache.ignite.cache.query. ScanQuery;
import org.apache.ignite.configuration. CacheConfiguration;
import org.apache.ignite.lang. IgniteBiPredicate;

public class IgniteAsyncStreamReceiver {
    public static void main(String[] args) throws Exception {
        System.out.println("Run Spring example!!"); 
        Ignition.setClientMode(true);
        Ignite ignite = Ignition.start();

        CacheConfiguration<Integer, Person> cacheConfiguration = new CacheConfiguration<Integer, Person>("myStreamCache");
        cacheConfiguration.setIndexedTypes(Integer.class, Person.class);
        cacheConfiguration.setCacheMode(CacheMode. PARTITIONED);

        IgniteCache<Integer, Person> cache = ignite.getOrCreateCache(cacheConfiguration);

        System.out.println();
        System.out.println(">>> Cache continuous query example started."); 

        // Create new continuous query. 
        ContinuousQuery<Integer, Person> qry = new ContinuousQuery<>();
        IgniteBiPredicate<Integer, Person> filter = new MyIgniteBiPredicate();
        Query<Cache. Entry<Integer, Person>> scanQuery = new ScanQuery<>(filter);
        qry.setInitialQuery(scanQuery);

        // Callback that is called locally when update notifications are received. 
        qry.setLocalListener(new CacheEntryUpdatedListener<Integer, Person>() {

            @Override public void onUpdated(Iterable<CacheEntryEvent<?  extends Integer, ?  extends Person>> evts) {
                for (CacheEntryEvent<?  extends Integer, ?  extends Person> e : evts)
                    System.out.println("Updated entry [key=" + e.getKey() + ", val=" + e.getValue() + ']');
            }
        });

        // This filter will be evaluated remotely on all nodes. 
        // Entry that pass this filter will be sent to the caller. 
        Factory<CacheEntryEventFilter<Integer, Person>> rmtFilterFactory = new MyRemoteFilterFactory();
        qry.setRemoteFilterFactory(rmtFilterFactory);

        // Execute query. 
        try (QueryCursor<Cache. Entry<Integer, Person>> cur = cache.query(qry)) {
            // Iterate through existing data. 
            for (Cache. Entry<Integer, Person> e : cur)
                System.out.println("Queried existing entry [key=" + e.getKey() + ", val=" + e.getValue() + ']');
            Thread.sleep(2000);
        }

    }

}

*RemoteFileFilterFactory implementation *
package ignite;

import javax.cache.configuration. Factory;
import javax.cache.event. CacheEntryEvent;
import javax.cache.event. CacheEntryEventFilter;
import javax.cache.event. CacheEntryListenerException;

import org.apache.ignite. Ignite;
import org.apache.ignite.lang. IgniteAsyncCallback;
import org.apache.ignite.resources. IgniteInstanceResource;

public class MyRemoteFilterFactory implements Factory<CacheEntryEventFilter<Integer, Person>> {
    private static final long serialVersionUID = 1L;

    @Override
    public CacheEntryEventFilter<Integer, Person> create() {
        return new CacheEntryFilter();
    }

    @IgniteAsyncCallback
    private static class CacheEntryFilter implements CacheEntryEventFilter<Integer, Person> {
        /** Ignite instance. */ 
        @IgniteInstanceResource
        private Ignite ignite;

        /** {@inheritDoc} */
        @Override
        public boolean evaluate(CacheEntryEvent<?  extends Integer, ?  extends Person> cache) throws CacheEntryListenerException {                
            System.out.println("Event  : "+ (cache.getValue()));
            return true;
        }
    }
}

IgniteBiPredicate implementation
package ignite;

import org.apache.ignite.lang. IgniteBiPredicate;

public class MyIgniteBiPredicate implements IgniteBiPredicate<Integer, Person> {

    /**
     * 
     */
    private static final long serialVersionUID = 1L;

    @Override
    public boolean apply(Integer key, Person person) {
        return person.getSal() < 1000;
    }

}

Person is a POJO -
package ignite;

public class Person {
    int id;
    int age;
    String name;
    int sal;
    public Person(int id, int age, String name, int sal) {
        super();
        this.id = id;
        this.age = age;
        this.name = name;
        this.sal = sal;
    }
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getSal() {
        return sal;
    }
    public void setSal(int sal) {
        this.sal = sal;
    }
    @Override
    public String toString() {
        StringBuilder builder = new StringBuilder();
        builder.append("Person [id=");
        builder.append(id);
        builder.append(", age=");
        builder.append(age);
        builder.append(", name=");
        builder.append(name);
        builder.append(", sal=");
        builder.append(sal);
        builder.append("]");
        return builder.toString();
    }

}

I am not getting any error on Ignite server console OR publisher/receiver client.  But my receiver just receive 1 or 2 records after initial cache snap.   I am referring https://github.com/apache/ignite/blob/master/examples/src/main/java/org/apache/ignite/examples/datagrid/CacheContinuousAsyncQueryExample.java -
Run Spring example!! 
[16:45:24] (wrn) Default Spring XML file not found (is IGNITE_HOME set?):  config/default-config.xml
Mar 07, 2017 4:45:24 PM java.util.logging. LogManager$RootLogger log
SEVERE: Failed to resolve default logging config file: config/java.util.logging.properties
[16:45:24]    __________  ________________ 
[16:45:24]   /  _/ ___/ |/ /  _/_  __/ __/ 
[16:45:24]  _/ // (7 7    // /  / / / _/   
[16:45:24] /___/\___/_/|_/___/ /_/ /___/  
[16:45:24] 
[16:45:24] ver.  1.9.0#20170302-sha1:a8169d0a
[16:45:24] 2017 Copyright(C) Apache Software Foundation
[16:45:24] 
[16:45:24] Ignite documentation: http://ignite.apache.org
[16:45:24] 
[16:45:24] Quiet mode. 
[16:45:24]   ^-- To see **FULL** console log here add -DIGNITE_QUIET=false or "-v" to ignite.{sh|bat}
[16:45:24] 
[16:45:24] OS: Windows 7 6.1 x86
[16:45:24] VM information: Java(TM) SE Runtime Environment 1.8.0_60-b27 Oracle Corporation Java HotSpot(TM) Client VM 25.60-b23
[16:45:24] Initial heap size is 16MB (should be no less than 512MB, use -Xms512m -Xmx512m). 
[16:45:24] Configured plugins:
[16:45:24]   ^-- None
[16:45:24] 
[16:45:25] Message queue limit is set to 0 which may lead to potential OOMEs when running cache operations in FULL_ASYNC or PRIMARY_SYNC modes due to message queues growth on sender and receiver sides. 
[16:45:25] Security status [authentication=off, tls/ssl=off]
[16:45:26] REST protocols do not start on client node.  To start the protocols on client node set '-DIGNITE_REST_START_ON_CLIENT=true' system property. 
[16:45:27] Performance suggestions for grid  (fix if possible)
[16:45:27] To disable, set -DIGNITE_PERFORMANCE_SUGGESTIONS_DISABLED=true
[16:45:27]   ^-- Enable server mode for JVM (add '-server' to JVM options)
[16:45:27]   ^-- Enable G1 Garbage Collector (add '-XX:+UseG1GC' to JVM options)
[16:45:27]   ^-- Specify JVM heap max size (add '-Xmx<size>[g|G|m|M|k|K]' to JVM options)
[16:45:27]   ^-- Set max direct memory size if getting 'OOME: Direct buffer memory' (add '-XX:MaxDirectMemorySize=<size>[g|G|m|M|k|K]' to JVM options)
[16:45:27]   ^-- Disable processing of calls to System.gc() (add '-XX:+DisableExplicitGC' to JVM options)
[16:45:27] Refer to this page for more performance suggestions: https://apacheignite.readme.io/docs/jvm-and-system-tuning
[16:45:27] 
[16:45:27] To start Console Management & Monitoring run ignitevisorcmd.{sh|bat}
[16:45:27] 
[16:45:27] Ignite node started OK (id=98218fc2)
[16:45:27] Topology snapshot [ver=9, servers=1, clients=2, CPUs=4, heap=1.5GB]

>>> Cache continuous query example started. 
Queried existing entry [key=0, val=Person [id=0, age=0, name=name_0, sal=0]]
Queried existing entry [key=1, val=Person [id=1, age=1, name=name_1, sal=100]]
Queried existing entry [key=2, val=Person [id=2, age=2, name=name_2, sal=200]]
Queried existing entry [key=3, val=Person [id=3, age=3, name=name_3, sal=300]]
Queried existing entry [key=4, val=Person [id=4, age=4, name=name_4, sal=400]]
Queried existing entry [key=5, val=Person [id=5, age=5, name=name_5, sal=500]]
Queried existing entry [key=6, val=Person [id=6, age=6, name=name_6, sal=600]]
Queried existing entry [key=7, val=Person [id=7, age=7, name=name_7, sal=700]]
Queried existing entry [key=8, val=Person [id=8, age=8, name=name_8, sal=800]]
Queried existing entry [key=9, val=Person [id=9, age=9, name=name_9, sal=900]]
Queried existing entry [key=30, val=Person [id=30, age=30, name=name_30, sal=0]]
Queried existing entry [key=31, val=Person [id=31, age=31, name=name_31, sal=100]]
Queried existing entry [key=32, val=Person [id=32, age=32, name=name_32, sal=200]]
Queried existing entry [key=33, val=Person [id=33, age=33, name=name_33, sal=300]]
Queried existing entry [key=34, val=Person [id=34, age=34, name=name_34, sal=400]]
Queried existing entry [key=35, val=Person [id=35, age=35, name=name_35, sal=500]]
Queried existing entry [key=36, val=Person [id=36, age=36, name=name_36, sal=600]]
Queried existing entry [key=37, val=Person [id=37, age=37, name=name_37, sal=700]]
Updated entry [key=10, val=Person [id=10, age=10, name=name_10, sal=1000]]
Updated entry [key=11, val=Person [id=11, age=11, name=name_11, sal=1100]]
<<NO RECORD after key 11.  SOme time it publish 3-4 *Updated Entry* and some time only 1-2>>

A:

When QueryCursor is closed, continuous query is cancelled.  It will work as you expect if you get rid of try-with-resources block.  I.e. this code
try (QueryCursor<Cache. Entry<Integer, Person>> cur = cache.query(qry)) {
    // Iterate through existing data. 
    for (Cache. Entry<Integer, Person> e : cur)
        System.out.println("Queried existing entry [key=" + e.getKey() + ", val=" + e.getValue() + ']');
    Thread.sleep(2000);
}

should be replaced with just this:
QueryCursor<Cache. Entry<Integer, Person>> cur = cache.query(qry);

for (Cache. Entry<Integer, Person> e : cur)
    System.out.println("Queried existing entry [key=" + e.getKey() + ", val=" + e.getValue() + ']');

