Socket Ayarları

Örnek

Şöyle yaparız

-Dhazelcast.socket.receive.buffer.size=10240 -Dhazelcast.socket.send.buffer.size=10240

Hazelcast SQL Sütun Tipleri

Sütun Tipleri burada

com.hazelcast.jet.sql.impl.connector.keyvalue.JavaClassNameResolver sütun tiplerinin hangi Java tipine karşılık geleceğini bilir.

HazelcastAPI ClientSchemaService Sınıfı

Giriş

Şu satırı dahil ederiz

import com.hazelcast.client.impl.clientside.ClientSchemaService;

replicateSchemaInCluster metodu

Call stack şöyle

replicateSchemaInCluster:140, ClientSchemaService (com.hazelcast.client.impl.clientside)
put:85, ClientSchemaService (com.hazelcast.client.impl.clientside)
putToSchemaService:137, CompactStreamSerializer (com.hazelcast.internal.serialization.impl.compact)
writeObject:148, CompactStreamSerializer (com.hazelcast.internal.serialization.impl.compact)
write:116, CompactStreamSerializer (com.hazelcast.internal.serialization.impl.compact)
write:109, CompactStreamSerializer (com.hazelcast.internal.serialization.impl.compact)
write:39, StreamSerializerAdapter (com.hazelcast.internal.serialization.impl)
toBytes:238, AbstractSerializationService (com.hazelcast.internal.serialization.impl)
toBytes:217, AbstractSerializationService (com.hazelcast.internal.serialization.impl)
toData:202, AbstractSerializationService (com.hazelcast.internal.serialization.impl)
toData:157, AbstractSerializationService (com.hazelcast.internal.serialization.impl)
toData:76, ClientProxy (com.hazelcast.client.impl.spi)
putInternal:553, ClientMapProxy (com.hazelcast.client.impl.proxy)
put:275, ClientMapProxy (com.hazelcast.client.impl.proxy)

Client CompactSerializer'ın kullandığı com.hazelcast.internal.serialization.impl.compact.Schema

nesnesini sunucuya gönderir. Böylece sunucu da bu nesnesi okuyabilir.

HazelcastAPI SchemaService Arayüzü

Giriş

Şu satırı dahil ederiz

import com.hazelcast.internal.serialization.impl.compact.SchemaService;

Kalıtım şöyle

SchemaService

  ClientSchemaService

  MemberSchemaService

  

Compact Serialization Custom Configuration

Örnek

Şu satırı dahil ederiz

import com.hazelcast.nio.serialization.compact.CompactSerializer;
import com.hazelcast.nio.serialization.compact.CompactReader;
import com.hazelcast.nio.serialization.compact.CompactWriter;

Örnek - Member Side Custom Configuration

Şöyle yaparız

public class Employee {
   ...
}

public class EmployeeSerializer implements CompactSerializer<Employee> {
  @Override
  public Employee read(CompactReader reader) {
    long id = reader.readInt64("id");
    String name = reader.readString("name");
    return new Employee(id, name);
  }

  @Override
  public void write(CompactWriter writer, Employee employee) {
    writer.writeInt64("id", employee.getId());
    writer.writeString("name", employee.getName());
  }

  @Override
  public Class<Employee> getCompactClass() {
    return Employee.class;
  }

  @Override
  public String getTypeName() {
    return "employee";
  }
}

Config config = new Config();
config.getSerializationConfig()
        .getCompactSerializationConfig()
        .addSerializer(new EmployeeSerializer());

Örnek - Client Side Custom Configuration

İstemci tarafından IMap.put işlemi için call stack şöyle . Yazılan byte[] nesnesi HeapData nesnesine çevrili.

write:16, MyWorkerSerializer (com.colak.serilization.compact.serializerconfiguration)
write:7, MyWorkerSerializer (com.colak.serilization.compact.serializerconfiguration)
buildSchema:396, CompactStreamSerializer (com.hazelcast.internal.serialization.impl.compact)
writeObject:147, CompactStreamSerializer (com.hazelcast.internal.serialization.impl.compact)
write:116, CompactStreamSerializer (com.hazelcast.internal.serialization.impl.compact)
write:109, CompactStreamSerializer (com.hazelcast.internal.serialization.impl.compact)
write:39, StreamSerializerAdapter (com.hazelcast.internal.serialization.impl)
toBytes:238, AbstractSerializationService (com.hazelcast.internal.serialization.impl)
toBytes:217, AbstractSerializationService (com.hazelcast.internal.serialization.impl)
toData:202, AbstractSerializationService (com.hazelcast.internal.serialization.impl)
toData:157, AbstractSerializationService (com.hazelcast.internal.serialization.impl)
toData:76, ClientProxy (com.hazelcast.client.impl.spi)
putInternal:553, ClientMapProxy (com.hazelcast.client.impl.proxy)
put:275, ClientMapProxy (com.hazelcast.client.impl.proxy)

ProcessorMetaSupplier.Context Arayüzü

Giriş

Şu satırı dahil ederiz

import com.hazelcast.jet.core.ProcessorMetaSupplier.Context;

Bu arayüz ProcessorMetaSupplier nesnesinin init() metoduna parametre olarak geçilir. Böylece ProcessorMetaSupplier nesnesi bazı ortam değişkenlerine erişebilir. 

Metodlar şöyle

HazelcastInstance hazelcastInstance();
JetInstance jetInstance();
long jobId();
long executionId();
JobConfig jobConfig();
int totalParallelism();
int localParallelism();
int memberCount();
String vertexName();
ILogger logger();
boolean snapshottingEnabled();
ProcessingGuarantee processingGuarantee();
long maxProcessorAccumulatedRecords();
boolean isLightJob();
Map<Address, int[]> partitionAssignment();
ClassLoader classLoader();
DataConnectionService dataConnectionService();
void checkPermission(@Nonnull Permission permission)

SchedLock

Giriş

Önemli sınıflar şöyle

1. HazelcastLockProvider

2. HazelcastLock

HazelcastLockProvider Sınıfı

lock metodu

Kod şöyle

public Optional<SimpleLock> lock(@NonNull LockConfiguration lockConfiguration) {

  final Instant now = ClockProvider.now();
  final String lockName = lockConfiguration.getName();
  final IMap<String, HazelcastLock> store = getStore();
  try {
    // lock the map key entry
    store.lock(lockName, keyLockTime(lockConfiguration), TimeUnit.MILLISECONDS);
    // just one thread at a time, in the cluster, can run this code
    // each thread waits until the lock to be unlock
    if (tryLock(lockConfiguration, now)) {
      return Optional.of(new HazelcastSimpleLock(this, lockConfiguration));
    }
  } finally {
    // released the map lock for the others threads
    store.unlock(lockName);
  }
  return Optional.empty();
}

1. shedlock_storage isimli IMap veri yapısında HazelcastLock nesneleri saklanır. 
2. eyLockTime() metodu now + LockAtMostUntil değerini verir. Yani IMap.lock() çağrısı gelecekteki bir zaman kadar bu key değerini kilitler
3. tryLock() metodu kilitli olan key değerinde 
1. HazelcastLock nesnesi yoksa yeni bir tane ekler ve true döner
2.  HazelcastLock nesnesi varsa ve bayatlamışsa, yeni HazelcastLock  ile değiştirir ve true döner
3. HazelcastLock nesnesi varsa ve bayatlamamışsa, kilitleyemediği için false döner