檢查Rails緩存的大小？

Question

有沒有辦法檢查Rails緩存的大小？

東西在靜脈：Rails.cache.size => 390 MB

我假設有數據存儲之間的一些微小的變化，但現在我不知道如何甚至開始檢查磁盤空間緩存佔用了。

Answer 1

完全取決於您的緩存存儲和您使用的後端。

這是從我的Heroku的實例中運行memcachier一個例子：

Rails.cache.stats 
# => {"xxx.memcachier.com:11211"=>{"curr_items"=>"278", "bytes"=>"3423104", "evictions"=>"0", "total_items"=>"7373", "curr_connections"=>"7", "total_connections"=>"97", "cmd_get"=>"141674", "cmd_set"=>"7373", "cmd_delete"=>"350", "cmd_flush"=>"6", "get_hits"=>"63716", "get_misses"=>"77958", "delete_hits"=>"162", "delete_misses"=>"188", "incr_hits"=>"0", "incr_misses"=>"0", "decr_hits"=>"0", "decr_misses"=>"0"}} 

FileStore沒有這樣的方法：

Rails.cache.stats 
# => NoMethodError: undefined method `stats' for #<ActiveSupport::Cache::FileStore:0x007ff1cbe905b0> 

當運行一個本地的memcached，我得到不同的結果集：

Rails.cache.stats 
# => {"127.0.0.1:11211"=>{"pid"=>"327", "uptime"=>"517931", "time"=>"1392163858", "version"=>"1.4.16", "libevent"=>"2.0.21-stable", "pointer_size"=>"64", "rusage_user"=>"2.257386", "rusage_system"=>"4.345445", "curr_connections"=>"15", "total_connections"=>"16", "connection_structures"=>"16", "reserved_fds"=>"20", "cmd_get"=>"0", "cmd_set"=>"0", "cmd_flush"=>"0", "cmd_touch"=>"0", "get_hits"=>"0", "get_misses"=>"0", "delete_misses"=>"0", "delete_hits"=>"0", "incr_misses"=>"0", "incr_hits"=>"0", "decr_misses"=>"0", "decr_hits"=>"0", "cas_misses"=>"0", "cas_hits"=>"0", "cas_badval"=>"0", "touch_hits"=>"0", "touch_misses"=>"0", "auth_cmds"=>"0", "auth_errors"=>"0", "bytes_read"=>"48", "bytes_written"=>"30", "limit_maxbytes"=>"67108864", "accepting_conns"=>"1", "listen_disabled_num"=>"0", "threads"=>"4", "conn_yields"=>"0", "hash_power_level"=>"16", "hash_bytes"=>"524288", "hash_is_expanding"=>"0", "malloc_fails"=>"0", "bytes"=>"0", "curr_items"=>"0", "total_items"=>"0", "expired_unfetched"=>"0", "evicted_unfetched"=>"0", "evictions"=>"0", "reclaimed"=>"0"}} 

Answer 2

除了@ phoet的回答，對於Redis cach E可以使用以下方法來獲得一個人類可讀的格式：

Rails.cache.stats["used_memory_human"] #=> 178.32M 

哪裏used_memory_human其實是可以運行Redis的服務器上INFO命令時所返回的任意鍵。