Memcached + Spring緩存

我試圖用Memcached設置Spring 3.1緩存解決方案。我已經成功地引入了ehcache（Spring已經爲此提供了支持）。然而，我堅持使用memcached的問題。我很抱歉提前的長度（這主要是樣板代碼）...Memcached + Spring緩存

我使用Java配置，所以我已經註釋了我的控制器配置以啓用緩存，如下所示。

@Configuration @EnableWebMvc @EnableCaching 
@ComponentScan("com.ehcache.reference.web") 
public class ControllerConfig extends WebMvcConfigurerAdapter { 
    //Bean to create ViewResolver and add the Resource handler 
}

這設置了三個控制器，允許對股票元素進行基本的CRUD操作。業務對象是這樣的：

public class Stock implements Serializable { 
    private String name; 
    private double cost; //This isn't a real app, don't care about correctness of value 
    //Getters, Setters contructors, etc... left out just a standard POJO

}

我使用MyBatis的，所以我創建了股票對象映射。然後將映射器注入到我的DAO中，然後將DAO注入到服務中。工作緩存（在兩種實現中）都發生在「服務」層中。下面是利用在DAO注入在服務層：

public class TradingServiceImpl implements TradingService { 

    @Autowired 
    private final StockDao stockDao; 

    public TradingServiceImpl(final StockDao stockDao) { 
    this.stockDao = stockDao; 
    } 

    @Override 
    public void addNewStock(final Stock stock) { 
    stockDao.save(stock); 
    } 

    @Override 
    @Cacheable(value = "stockCache") 
    public Stock getStock(final String stockName) { 
    return stockDao.findByName(stockName); 
    } 

    @Override 
    public List<Stock> getAll() { 
    return stockDao.findAll(); 
    } 

    @Override 
    @CacheEvict(value = "stockCache", key = "#stock.name") 
    public void removeStock(final Stock stock) { 
    stockDao.delete(stock); 
    } 

    @Override 
    @CacheEvict(value = "stockCache", key = "#stock.name") 
    public void updateStock(final Stock stock) { 
    stockDao.update(stock); 
    } 
}

下面是示例控制器，這是應該緩存顯示所有的股票（當加入一隻股票該高速緩存被完全逐出的結果，更新，或從數據庫中刪除）：

@Controller 
public class ListAllStocksController { 

    @Autowired 
    private TradingService tradingService; 

    @Cacheable("viewCache") 
    @RequestMapping(value = "listStocks.html", method = RequestMethod.GET) 
    public ModelAndView displayAllStocks() { 
    //The SerializableModelAndView extends Spring's ModelAndView and implements Serializable due to spymemcached not being able to add a non-serializable object to the cache 
    final ModelAndView mav = new SerializableModelAndView("listStocks"); 
    mav.addObject("stocks", tradingService.getAll()); 
    return mav; 
    } 

    @CacheEvict(value = "viewCache", allEntries = true) 
    @RequestMapping(value = "editStock.html", method = RequestMethod.POST, params = "submit=Edit") 
    public ModelAndView editStock(final Stock stock, final BindingResult result) { 
    final ModelAndView mav = new ModelAndView("redirect:listStocks.html"); 
    tradingService.updateStock(stock); 
    return mav; 
    } 

    @CacheEvict(value = "viewCache", allEntries = true) 
    @RequestMapping(value = "listStocks.html", method = RequestMethod.POST, params = "submit=Delete") 
    public ModelAndView deleteStockAction(@RequestParam("name") final String name) { 
    final ModelAndView mav = new ModelAndView("redirect:listStocks.html"); 
    tradingService.removeStock(stock); 
    return mav; 
    } 

}

這是我小的CacheManager：

public class MemCacheManager extends AbstractCacheManager { 
    private final Collection<MemCache> internalCaches; 

    public MemCacheManager(final Collection<MemCache> internalCaches) { 
    this.internalCaches = internalCaches; 
    } 

    @Override 
    protected Collection<? extends Cache> loadCaches() { 
    Assert.notNull(internalCaches, "A collection caches is required and cannot be empty"); 
    return internalCaches; 
    } 
}

這裏是我的memcache類的樣子：

public class MemCache implements Cache { 

    private MemcachedClient cache; 
    private final String name; 
    private static final Logger LOGGER = Logger.getLogger(MemCache.class); 

    public MemCache(final String name, final int port) throws URISyntaxException { 
    this.name = name; 
    try { 
     cache = new MemcachedClient(AddrUtil.getAddresses("localhost:" + port)); 
     final SerializingTranscoder stc = (SerializingTranscoder) cache.getTranscoder(); 
     stc.setCompressionThreshold(600000); 
    } catch (final IOException e) { //Let it attempt to reconnect } 
    } 

    @Override 
    public String getName() { 
    return name; 
    } 

    @Override 
    public Object getNativeCache() { 
    return cache; 
    } 

    @Override 
    public ValueWrapper get(final Object key) { 
    Object value = null; 
    try { 
     value = cache.get(key.toString()); 
    } catch (final Exception e) { 
     LOGGER.warn(e); 
    } 
    if (value == null) { 
     return null; 
    } 
    return new SimpleValueWrapper(value); 
    } 

    @Override 
    public void put(final Object key, final Object value) { 
    cache.set(key.toString(), 7 * 24 * 3600, value); 
    Assert.assertNotNull(get(key)); //This fails on the viewCache 
    } 

    @Override 
    public void evict(final Object key) { 
    this.cache.delete(key.toString()); 
    } 

    @Override 
    public void clear() { 
    cache.flush(); 
    } 
}

我試過這與CouchBase和常規memcached。下面的設置顯示了memcached只能自行啓動。

@Configuration @EnableCaching @Profile("memcached") 
public class MemCacheConfiguration implements CachingConfigurer { 

    @Override @Bean 
    public CacheManager cacheManager() { 
    CacheManager cacheManager; 
    try { 
     cacheManager = new MemCacheManager(internalCaches()); 
     return cacheManager; 
    } catch (final URISyntaxException e) { 
     throw new RuntimeException(e); 
    } 
    } 

    @Bean 
    public Collection<MemCache> internalCaches() throws URISyntaxException { 
    final Collection<MemCache> caches = new ArrayList<MemCache>(); 
    // caches.add(new MemCache("stockCache", 11212)); 
    caches.add(new MemCache("viewCache", 11211)); 
    return caches; 
    } 

    @Override 
    public KeyGenerator keyGenerator() { 
    return new DefaultKeyGenerator(); 
    } 

}

在上面的例子中，我們將簡單地使用memcached。這是我看到當我第一次啓動應用程序並點擊列表控制器日誌：

58513 [qtp1656205248-16] TRACE org.springframework.cache.interceptor.CacheInterceptor - Computed cache key 0 for operation CacheableOperation[public org.springframework.web.servlet.ModelAndView com.ehcache.reference.web.ListAllStocksController.displayAllStocks()] caches=[viewCache] | condition='' | key='0' 
58519 [qtp1656205248-16] WARN com.memcache.MemCache - Retrieved: null from the cache 'viewCache' at <0> key of type <java.lang.Integer> 
58519 [qtp1656205248-16] ERROR com.memcache.MemCache - Returning null 
58520 [qtp1656205248-16] DEBUG org.mybatis.spring.SqlSessionUtils - Creating a new SqlSession 
58520 [qtp1656205248-16] DEBUG org.mybatis.spring.SqlSessionUtils - SqlSession [[email protected]] was not registered for synchronization because synchronization is not active 
58520 [qtp1656205248-16] DEBUG org.mybatis.spring.transaction.SpringManagedTransaction - JDBC Connection [[email protected]] will not be managed by Spring 
58521 [qtp1656205248-16] DEBUG com.ehcache.reference.dao.StockMapper.findAll - ooo Using Connection [[email protected]] 
58521 [qtp1656205248-16] DEBUG com.ehcache.reference.dao.StockMapper.findAll - ==> Preparing: SELECT * from STOCK 
58521 [qtp1656205248-16] DEBUG com.ehcache.reference.dao.StockMapper.findAll - ==> Parameters: 
58521 [qtp1656205248-16] DEBUG org.mybatis.spring.SqlSessionUtils - Closing non transactional SqlSession [[email protected]] 
58521 [qtp1656205248-16] WARN com.memcache.MemCache - Setting: ModelAndView: reference to view with name 'listStocks'; model is {stocks=[]} into the cache 'viewCache' at <0> key of type <java.lang.Integer> 
58527 [qtp1656205248-16] WARN com.memcache.MemCache - Retrieved: ModelAndView: materialized View is [null]; model is null from the cache 'viewCache' at <0> key of type <java.lang.Integer>

這一切看起來是正確的，這是一個新鮮的推出，應該沒有在緩存中。我現在將一個庫存添加到緩存中：

263036 [qtp1656205248-14] DEBUG org.mybatis.spring.SqlSessionUtils - Creating a new SqlSession 
263036 [qtp1656205248-14] DEBUG org.mybatis.spring.SqlSessionUtils - SqlSession [[email protected]] was not registered for synchronization because synchronization is not active 
263038 [qtp1656205248-14] DEBUG org.mybatis.spring.transaction.SpringManagedTransaction - JDBC Connection [[email protected]] will not be managed by Spring 
263038 [qtp1656205248-14] DEBUG com.ehcache.reference.dao.StockMapper.save - ooo Using Connection [[email protected]] 
263038 [qtp1656205248-14] DEBUG com.ehcache.reference.dao.StockMapper.save - ==> Preparing: INSERT INTO STOCK (name, cost) VALUES (?, ?) 
263039 [qtp1656205248-14] DEBUG com.ehcache.reference.dao.StockMapper.save - ==> Parameters: A(String), 1.0(Double) 
263039 [qtp1656205248-14] DEBUG org.mybatis.spring.SqlSessionUtils - Closing non transactional SqlSession [[email protected]] 
263039 [qtp1656205248-14] TRACE org.springframework.cache.interceptor.CacheInterceptor - Invalidating cache key 0 for operation CacheEvictOperation[public org.springframework.web.servlet.ModelAndView com.ehcache.reference.web.AddStockController.addNewStock(com.ehcache.reference.business.Stock,org.springframework.validation.BindingResult)] caches=[viewCache] | condition='' | key='0',false,false on method public org.springframework.web.servlet.ModelAndView com.ehcache.reference.web.AddStockController.addNewStock(com.ehcache.reference.business.Stock,org.springframework.validation.BindingResult) 
263039 [qtp1656205248-14] WARN com.memcache.MemCache - Evicting value at <0> in cache 'viewCache' 
263049 [qtp1656205248-18] TRACE org.springframework.cache.interceptor.CacheInterceptor - Computed cache key 0 for operation CacheableOperation[public org.springframework.web.servlet.ModelAndView com.ehcache.reference.web.ListAllStocksController.displayAllStocks()] caches=[viewCache] | condition='' | key='0' 
263051 [qtp1656205248-18] WARN com.memcache.MemCache - Retrieved: null from the cache 'viewCache' at <0> key of type <java.lang.Integer> 
263051 [qtp1656205248-18] ERROR com.memcache.MemCache - Returning null 
263051 [qtp1656205248-18] DEBUG org.mybatis.spring.SqlSessionUtils - Creating a new SqlSession 
263051 [qtp1656205248-18] DEBUG org.mybatis.spring.SqlSessionUtils - SqlSession [[email protected]] was not registered for synchronization because synchronization is not active 
263051 [qtp1656205248-18] DEBUG org.mybatis.spring.transaction.SpringManagedTransaction - JDBC Connection [[email protected]] will not be managed by Spring 
263051 [qtp1656205248-18] DEBUG com.ehcache.reference.dao.StockMapper.findAll - ooo Using Connection [[email protected]] 
263051 [qtp1656205248-18] DEBUG com.ehcache.reference.dao.StockMapper.findAll - ==> Preparing: SELECT * from STOCK 
263052 [qtp1656205248-18] DEBUG com.ehcache.reference.dao.StockMapper.findAll - ==> Parameters: 
263053 [qtp1656205248-18] DEBUG org.mybatis.spring.SqlSessionUtils - Closing non transactional SqlSession [[email protected]] 
263053 [qtp1656205248-18] WARN com.memcache.MemCache - Setting: ModelAndView: reference to view with name 'listStocks'; model is {stocks=[Stock Name: <A>  Current Cost <1.0>]} into the cache 'viewCache' at <0> key of type <java.lang.Integer> 
263055 [qtp1656205248-18] WARN com.memcache.MemCache - Retrieved: ModelAndView: materialized View is [null]; model is null from the cache 'viewCache' at <0> key of type <java.lang.Integer>

減去最後一行，看起來都是正確的。下面是從memcached的--vv我的輸出：

<156 get 0    ##Initial listing of all 
>156 END     
<156 set 0 1 604800 79 ##Cache initial result on startup 
>156 STORED 
<156 get 0 
>156 sending key 0 
>156 END 
<156 delete 0   ##Invalidation when stock added 
>156 DELETED 
<156 get 0    ##Add redirects to the get page 
>156 END 
<156 set 0 1 604800 79 ##Store the new value 
>156 STORED 
<156 get 0 
>156 sending key 0  ##Refresh the page 
>156 END

這裏的unfun的一點是，當我添加一個股票系統，我重定向到displayAllStocks方法。它最初是正確的，但是如果我刷新頁面，我會發送原始版本（不顯示股票的版本）。我很困難，我不確定在這一點上可能會導致這個問題。如果我以任何方式使緩存失效，重定向將正常工作。這是後續刷新，我檢索似乎是第一個價值投入（已被刪除）

這是一個配置問題？ memcache或spymemcached中的限制/錯誤還是我MemCache代碼中的一個錯誤？

來源

2012-07-06 Scott

在TradingServiceImpl中，getStock方法總是從緩存中返回與股票名稱無關的相同對象。您應該將其更改爲：

@Override 
    @Cacheable(value = "stockCache", key="#stockName") 
    public Stock getStock(final String stockName) { 
    return stockDao.findByName(stockName); 
    }

您在哪裏驅逐viewCache？我沒有在你的代碼中看到它。

如果你想通過Spring 3.1緩存抽象使用memcached，你可以使用Simple-Spring-Memcached（當前的快照版本 - 你需要從源代碼構建它）。 Here你可以找到示例配置如何使用SSM將memcached與Spring Cache集成。
示例項目：spring-cache-integration-test使用此集成可在SSM svn中獲得。

更新：Simple Spring Memcached 3.0.0與Spring Cache集成已經可用。

來源

2012-07-06 17:05:07 ragnor

您可以檢查每一步中存儲在memcached中的內容嗎？使用putty/telent連接到memcached服務器並檢查viewCache是否已更新。 – ragnor 2012-07-06 20:58:57

上面的日誌只顯示viewCache。我可以看到一個值被設置，但它不是正確的值。我猜是因爲擴展模型和視圖實現了可序列化，以及沒有正確序列化的東西。 – Scott 2012-07-09 12:58:18

你可以嘗試使用JSON序列化Simple Spring Memcached，這樣你就可以看到存儲在緩存中的究竟是什麼？ – ragnor 2012-07-10 05:44:33

Memcached + Spring緩存

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