caching

问题 What's the best option for avoiding key collisions between multiple sites running on the same server using APC for user caching? I've run into issues where 2 or more sites were using the same cache key and expecting different types of items to be stored under it--one expecting a json string, the other an array, another an object. Is their a way to segment APC by site? BTW: I'm using APC with Apache running prefork and mod_php. 回答1: Perhaps you could append the server hostname to the key, you

问题 I want to use ZODB with as little caching as possible. For this, I'm creating ZODB database instance and opening it like this: db = DB('/home/me/example.db', cache_size=1, cache_size_bytes=1) db_conn = db.open_then_close_db_when_connection_closes() db_conn is the only connection of db . I'm verifying that both its target cache size parameters are set by checking db_conn._cache.cache_size and db_conn._cache.cache_size_bytes , which evaluate to 1 each. In the database, I store lots (could be

问题 I'm currently looking into the possibility of implementing ETags in a Web Server, to support only the conditional GET. The Web Server is written in C++ and runs only on a Windows OS. After doing some research I have a few questions...Do servers that implement this feature generally cache the ETag GUID for a particular file? I'm not too familiar with the Apache code base, but I was able to locate the ap_condition_if_none_match function but, it isn't entirely clear to me how they check the GUID

问题 My code requires continuously computing a value from the following function: inline double f (double x) { return ( tanh( 3*(5-x) ) *0.5 + 0.5); } Profiling indicates that this part of the program is where most of the time is spent. Since the program will run for weeks if not months, I would like to optimize this operation and am considering the use of a lookup table. I know that the efficiency of a lookup table depends on the size of the table itself, and on the way it's designed. Currently I

问题 I created a new solution from WebApi .Net Core 2.0 template in Visual Studio. I added the following in startup. public void ConfigureServices(IServiceCollection services) { services.AddMvc(); services.AddHttpCacheHeaders(opt => opt.MaxAge = 600); services.AddResponseCaching(); } public void Configure(IApplicationBuilder app, IHostingEnvironment env) { if (env.IsDevelopment()) { app.UseDeveloperExceptionPage(); } app.UseResponseCaching(); app.UseHttpCacheHeaders(); app.UseMvc(); } Then, with

问题 I am trying to use second level cache in wildfly8.2 I am setting the properties via JavaConfig Properties properties = new Properties(); properties.setProperty("hibernate.hbm2ddl.auto", hibernateHbm2ddlAuto); properties.setProperty("hibernate.dialect", hibernateDialect); properties.setProperty("hibernate.show_sql", "true"); properties.setProperty("hibernate.cache.use_second_level_cache", "true"); properties.setProperty("hibernate.cache.use_query_cache" , "true"); but I get the following error

问题 I am trying to get the expiry date of a HttpRuntime.Cache object, as per this answer: https://stackoverflow.com/a/350374/1778169 The method is: private DateTime GetCacheUtcExpiryDateTime(string cacheKey) { object cacheEntry = Cache.GetType().GetMethod("Get", BindingFlags.Instance | BindingFlags.NonPublic).Invoke(Cache, new object[] { cacheKey, 1 }); PropertyInfo utcExpiresProperty = cacheEntry.GetType().GetProperty("UtcExpires", BindingFlags.NonPublic | BindingFlags.Instance); DateTime

问题 Im looking for an explanation to the following code from Brian Goetz's concurrency book. public V compute(final A arg) throws InterruptedException { while (true) { Future<V> f = cache.get(arg); if (f == null) { Callable<V> eval = new Callable<V>() { public V call() throws InterruptedException { return c.compute(arg); } }; FutureTask<V> ft = new FutureTask<V>(eval); f = cache.putIfAbsent(arg, ft); if (f == null) { f = ft; ft.run(); } } try { return f.get(); } catch (CancellationException e) {

问题 GraphQL works as a query language posting always against a single end point. So most caching tools can't be used. So is network caching completely impossible with GraphQL? Is client side caching the only possible way to cache? Or is there a workaround? 回答1: When using HTTP transport for your GraphQL API you can cache the HTTP responses just like any other HTTP traffic. Typically the CDN will hash the full request and then cache the response with that hash. When the same request comes in next

问题 I have an application that displays a list of photo albums and then, once an album is selected, displays photos in that album. I am using the memory cache/disk cache implementation from one of the google examples (since the photos are loaded from a website). Everything is working fine, but the disk cache initialization takes place every time an album is chosen, and the initialization takes considerable amount of time. I'd like to declare the disk cache "globally" and use it for all albums. I