Elasticsearch Java Client连接池

按照Elasticsearch API，在Java端使用是ES服务需要创建Java Client，但是每一次连接都实例化一个client，对系统的消耗很大，即使在使用完毕之后将client close掉，由于服务器不能及时回收socket资源，极端情况下会导致服务器达到最大连接数。

为了解决上述问题并提高client利用率，可以参考使用池化技术复用client。

import org.elasticsearch.client.Client;import org.elasticsearch.client.transport.TransportClient;import org.elasticsearch.common.settings.ImmutableSettings;import org.elasticsearch.common.settings.Settings;import org.elasticsearch.common.transport.InetSocketTransportAddress;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;import java.util.concurrent.ConcurrentHashMap;/** * Created by tgg on 16-3-17. */public class ClientHelper {    private Settings setting;    private Map<String, Client> clientMap = new ConcurrentHashMap<String, Client>();    private Map<String, Integer> ips = new HashMap<String, Integer>(); // hostname port    private String clusterName = "elasticsearch";    private ClientHelper() {        init();        //TO-DO 添加你需要的client到helper    }    public static final ClientHelper getInstance() {        return ClientHolder.INSTANCE;    }    private static class ClientHolder {        private static final ClientHelper INSTANCE = new ClientHelper();    }    /**     * 初始化默认的client     */    public void init() {        ips.put("127.0.0.1", 9300);        setting = ImmutableSettings                .settingsBuilder()                .put("client.transport.sniff",true)                .put("cluster.name","elasticsearch").build();        addClient(setting, getAllAddress(ips));    }    /**     * 获得所有的地址端口     *     * @return     */    public List<InetSocketTransportAddress> getAllAddress(Map<String, Integer> ips) {        List<InetSocketTransportAddress> addressList = new ArrayList<InetSocketTransportAddress>();        for (String ip : ips.keySet()) {            addressList.add(new InetSocketTransportAddress(ip, ips.get(ip)));        }        return addressList;    }    public Client getClient() {        return getClient(clusterName);    }    public Client getClient(String clusterName) {        return clientMap.get(clusterName);    }    public void addClient(Settings setting, List<InetSocketTransportAddress> transportAddress) {        Client client = new TransportClient(setting)                .addTransportAddresses(transportAddress                        .toArray(new InetSocketTransportAddress[transportAddress.size()]));        clientMap.put(setting.get("cluster.name"), client);    }}