memcached

Redis与Memcached的区别

由 非 Y 不嫁゛ 提交于 2019-12-12 15:59:04
【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> memcached和redis的区别 区别： 1、数据类型不同，memcached只支持key-value，redis支持String，List，Map，set，sorted Set 2、memcached保存在内存中，redis内存和文件里面都有保存，宕机之后memcached完全丢失，redis还可以从文件中恢复到内存中 3、memcahed的内存分配是基于slab划分的，通过page（默认1M）申请内存，然后每个slab会划分为好多的chunk，数据都存储在chunk中，redis为了屏蔽不同平台之间的差异，redis对内存分配函数进行了一层封装，程序中统一使用zmalloc，zfree一系列函数 4、memcahed基于libevent网络库，而redis是基于epoll网络模型，紧接着说下， select，poll，epoll的区别 select同步阻塞，最大文件描述符1024， poll同步阻塞，没有最大文件描述符限制， epoll异步非阻塞，没有最大文件描述符限制。 select是轮询式的事件通知， epoll是回调事件通知callback 5、memcahed多线程的，redis是单线程的，redis使用epoll，这就是redis为什么使用单线程性能一点也不逊于memcahed的原因 6

Django的缓存机制

由 此生再无相见时 提交于 2019-12-12 15:34:25
本文目录 一 缓存介绍 二 Django中的6种缓存方式 三 Django6种缓存的配置 四 Django中的缓存应用 回到目录 一 缓存介绍 在动态网站中,用户所有的请求,服务器都会去数据库中进行相应的增,删,查,改,渲染模板,执行业务逻辑,最后生成用户看到的页面. 当一个网站的用户访问量很大的时候,每一次的的后台操作,都会消耗很多的服务端资源,所以必须使用缓存来减轻后端服务器的压力. 缓存是将一些常用的数据保存内存或者memcache中,在一定的时间内有人来访问这些数据时,则不再去执行数据库及渲染等操作,而是直接从内存或memcache的缓存中去取得数据,然后返回给用户. 回到目录 二 Django中的6种缓存方式 开发调试缓存 内存缓存 文件缓存 数据库缓存 Memcache缓存(使用python-memcached模块) Memcache缓存(使用pylibmc模块) 经常使用的有文件缓存和Mencache缓存 回到目录 三 Django6种缓存的配置 1.2.1 开发调试(此模式为开发调试使用,实际上不执行任何操作) settings.py文件配置 CACHES = { 'default': { 'BACKEND': 'django.core.cache.backends.dummy.DummyCache', # 缓存后台使用的引擎 'TIMEOUT': 300, #

How to selectively clear cache (using tags or other option) with Memchached backend and Zend Framework

由 旧城冷巷雨未停 提交于 2019-12-12 14:51:58
问题 We use Memcached and Zend Framework in our web project. Now, we need to clean cache selectively using tags as specified in Zend_Cache API. Unfortunately, memcached doesn't support tags. I have found these workarounds: Memcached-tag project. Has anybody tested it? How to implement it with Zend? Use wildchards like in this question, but it seems a bit confusing, less transparent and harder to implement with Zend. Use this implementation or this one, for supporting tags in Memcached, beeing

Error when starting Memcached: failed to listen [closed]

由 流过昼夜 提交于 2019-12-12 14:32:56
问题 It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center. Closed 6 years ago . I have run Memcached on my Server for 2 month. Yesterday it stopped working. No idea why. So I tried: root@xyz:~# killall memcached root@xyz:~# /etc/init.d/memcached stop Stopping memcached: memcached. root@xyz:~

Django Memcached Cache Disappears

由 不打扰是莪最后的温柔 提交于 2019-12-12 13:34:08
问题 I had my django application configured with memcached and everything was working smoothly. I am trying to populate the cache over time, adding to it as new data comes in from external API's. Here is the gist of what I have going on: main view api_query, more_results = apiQuery(**params) cache_key = "mystring" cache.set(cache_key, data_list, 600) if more_results: t = Thread(target = 'apiMoreResultsQuery', args = (param1, param2, param3)) t.daemon = True t.start() more results function cache

upstream prematurely closed connection while reading response header from upstream, client

由 ぃ、小莉子 提交于 2019-12-12 11:26:20
问题 I'm getting this error from /var/log/messages on my FreeBSD box. I'm using nginx and spawn-fcgi with memcache and apc modules enabled. upstream prematurely closed connection while reading response header from upstream, client HTTP/1.1", upstream: "fastcgi://unix:/tmp/fcgi.sock:", host: 回答1: I've had a similar error with unicorn + nginx. The end result was that the unicorn was timing out due to a firewall misconfiguration, dieing off and leaving NGINX clueless as to what to do (nginx would

Any distributed cache systems that allows for tagging content?

由 旧时模样 提交于 2019-12-12 11:10:11
问题 I'd like to know if there is any distributed cache systems like memcached, velocity or sharedcache that allows me to tag content with more than just it's name, or that can relate items to eachother, so if i invalidate the cache for one item it also invalidates the related items too. eg. if i have two pages that reference the same data and that data changes, i'd like the cache for the two referencing pages to invalidate. or is this an addition to one of those projects begging to be developed?

Should I store an array or individual items in Memcache?

由 元气小坏坏 提交于 2019-12-12 09:25:36
问题 Right now we are storing some query results on Memcache. After investigating a bit more, I've seen that many people save each individual item in Memcache. The benefit of doing this is that they can get these items from Memcache on any other request. Store an array $key = 'page.items.20'; if( !( $results = $memcache->get($key) ) ) { $results = $con->execute('SELECT * FROM table LEFT JOIN .... LIMIT 0,20')->fetchAll(); $memcache->save($results, $key, 3600); } ... PROS: Easier CONS: If I change

Is it okay to save lots of information in $_SESSION?

由 不打扰是莪最后的温柔 提交于 2019-12-12 08:34:27
问题 I need to store many arrays in $_SESSION to prevent retrieving information from MySQL. Is it okay? How much is "too much" information in $_SESSION or there isn't any "too much"? Thanks. P.S. Or it's better to use http://php.net/manual/en/book.memcache.php ? 回答1: The limit of data you can store inside a session is limited by the session storage layer. The default sessions store is the file-system and one session is stored into one file. The name of the session variable/array-key is stored as

memcache connect vs addServer

由 Deadly 提交于 2019-12-12 08:23:42
问题 I was looking at the php docs on memcache and noticed that instead of doing $mem->connect('localhost', 11211) I can do instead $mem->addServer('localhost', 11211) And this way if I don't end up using the memcache connection, it won't bother connecting. This got me wondering, why would someone ever use connect() over addServer() ? It just seems like a possible unnecessary connection. Am I missing something? 回答1: connect and pconnect seem to be more low level calls, that perform a single task
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