java - 无法使用 php memcached 获取使用 spymemcached 设置的项目

Question

我正在使用 spymemcached。我设置了几个项目。然后我运行一个 php 脚本，但是我无法使用 php memcached 获取所有这些项目。 PHP-Memcached 只能部分检索这些项目。

我无法更改 php 的散列算法或分发策略。在我们的系统中，我们使用默认散列(根据 php.net 文档，这是 jenkin 的一次一个)。分配策略是 php-memcached 的模数。我读过 spymemcached 使用一致的散列。有什么方法可以在 spymemcached 中使用模哈希。

换句话说，我怎样才能使 spymemcached 的设置操作或任何其他存储操作与 php-memcached 的获取操作兼容？

如果 spymemcached 无法做到这一点，java 中是否有任何其他 memcached 客户端允许我这样做？

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Java代码:

public static void main(String [] args) {
    List<InetSocketAddress> addrs = new ArrayList<>();
    addrs.add(new InetSocketAddress("10.90.12.87", 11211));
    addrs.add(new InetSocketAddress("10.90.12.87", 11311));
    try {
        MemcachedClient memcache = new MemcachedClient(addrs);
        memcache.add("foo", 0, "bar");
        memcache.add("sample", 0, "key");
        memcache.add("try", 0, "another");
        memcache.add("ax-spadg-list", 0, "3045,6645");
    } catch (IOException ex) {
        Logger.getLogger(CategoryDataOperator.class.getName()).log(Level.SEVERE, null, ex);
    }
    System.out.println("Done");
}

PHP代码:

<?php
$mem = new Memcached();
$mem->addServer('10.90.12.87', 11211);
$mem->addServer('10.90.12.87', 11311);
var_dump $mem->get('foo');
var_dump($mem->get('try'));
var_dump($mem->get('sample'));
var_dump($mem->get('ax-spadg-list'));

Answer 1

问题是关于Hash的，默认的php-memcached hash是

(Jenkins one-at-a-time) item key hashing algorithm

而 spymemcached 哈希列表是:

• NATIVE_HASH:只是 Native hash (String.hashCode()). 与默认的 php-memcached Memcached::HASH_DEFAULT 不匹配/li>
• CRC_HASH => Memcached::HASH_CRC
• FNV1_64_HASH => Memcached::HASH_FNV1_64
• FNV1A_64_HASH => Memcached::HASH_FNV1A_64
• FNV1_32_HASH => Memcached::HASH_FNV1_32
• FNV1A_32_HASH => Memcached::HASH_FNV1A_32
• KETAMA_HASH => “ketama 使用的基于 MD5 的哈希算法。”所以也许 Memcached::HASH_MD5 但无论如何都不是 Memcached::HASH_DEFAULT

因此，如果您不能更改 PHP 客户端配置或扩展 spymemcached 库，则两个库之间不会直接匹配。

解决方案 1:如果您查看 history (你可以有一个 php 客户端哈希修改的例子)。

解决方案 2:否则您可以创建一个 JenkinHash 类(我复制了 Xmemcached 代码:https://code.google.com/p/xmemcached/source/browse/trunk/src/main/java/net/rubyeye/xmemcached/HashAlgorithm.java?r=801#176 [但要考虑 Xmemcached 许可证并将作者/许可证保留在源代码中] )

import net.spy.memcached.HashAlgorithm;

import java.io.UnsupportedEncodingException;

public class JenkinsHash implements HashAlgorithm {
    @Override
    public long hash(String k) {
        try {
            int hash = 0;
            for (byte bt : k.getBytes("utf-8")) {
                hash += (bt & 0xFF);
                hash += (hash << 10);
                hash ^= (hash >>> 6);
            }
            hash += (hash << 3);
            hash ^= (hash >>> 11);
            hash += (hash << 15);
            return hash;
        } catch (UnsupportedEncodingException e) {
            throw new IllegalStateException("Hash function error", e);
        }
    }
}

然后:

import net.spy.memcached.*;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.util.ArrayList;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;

public class Main {

    public static void main(String[] args) throws IOException {
        List<InetSocketAddress> addrs = new ArrayList<InetSocketAddress>();
        addrs.add(new InetSocketAddress("127.0.0.1", 11211));
        addrs.add(new InetSocketAddress("172.28.29.22", 11211));
        try {
            ConnectionFactory connectionFactory = new ConnectionFactoryBuilder()
                .setProtocol(ConnectionFactoryBuilder.Protocol.TEXT)
                .setHashAlg(new JenkinsHash())
                .setLocatorType(ConnectionFactoryBuilder.Locator.ARRAY_MOD).build();
            MemcachedClient memcache = new MemcachedClient(connectionFactory, addrs);
            memcache.add("foo", 0, "bar2");
            memcache.add("sample", 0, "key");
            memcache.add("try", 0, "another");
            memcache.add("ax-spadg-list", 0, "3045,6645");
        } catch (IOException ex) {
            Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
        }
        System.out.println("Done");
    }
}

使用 php 脚本:

<?php

$memcached = new Memcached();
$memcached->addserver('127.0.0.1', 11211);
$memcached->addserver('172.28.29.22', 11211);
var_dump($memcached->get('foo'));
var_dump($memcached->get('try'));
var_dump($memcached->get('sample'));
var_dump($memcached->get('ax-spadg-list'));

测试:

$ echo "flush_all" | nc 172.28.29.22 11211 && echo "flush_all" | nc 127.0.0.1 11211
OK
OK
$ php mem.php 
bool(false)
bool(false)
bool(false)
bool(false)

RUN JAVA

$ php mem.php 
string(4) "bar2"
string(7) "another"
string(3) "key"
string(9) "3045,6645"

解决方案 3: 使用 https://code.google.com/p/xmemcached/使用 ONE_AT_A_TIME 哈希算法

import net.rubyeye.xmemcached.HashAlgorithm;
import net.rubyeye.xmemcached.MemcachedClient;
import net.rubyeye.xmemcached.MemcachedClientBuilder;
import net.rubyeye.xmemcached.XMemcachedClientBuilder;
import net.rubyeye.xmemcached.exception.MemcachedException;
import net.rubyeye.xmemcached.impl.ArrayMemcachedSessionLocator;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.TimeoutException;

public class Main {

    public static void main(String[] args) throws IOException, InterruptedException, MemcachedException, TimeoutException {
        List<InetSocketAddress> addrs = new ArrayList<InetSocketAddress>();
        addrs.add(new InetSocketAddress("127.0.0.1", 11211));
        addrs.add(new InetSocketAddress("172.28.29.22", 11211));
        MemcachedClientBuilder builder = new XMemcachedClientBuilder(addrs);
        builder.setSessionLocator(new ArrayMemcachedSessionLocator(HashAlgorithm.ONE_AT_A_TIME));
        MemcachedClient memcachedClient = builder.build();
        memcachedClient.set("foo", 0, "bar2");
        memcachedClient.set("sample", 0, "key");
        memcachedClient.set("try", 0, "another");
        memcachedClient.set("ax-spadg-list", 0, "3045,6645");
        memcachedClient.shutdown();
        System.out.println("Done");
    }
}