Re:Twilio incident and Redis
by dkulchenko on Wednesday July 24, 2013 @06:38PM
(#6099578)
Redis is not an ephemeral database when used in Twilio's configuration. When configured with an AOF with fsync set to 'always', Redis will be as durable if not more durable than postgres and the like.
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To expand on that a bit: when redis is in AOF mode, all write commands are appended to a journal file. When fsync is set to 'always', this journal file is fsynced on every write.
Redis has a reputation as an "ephemeral database", because it's usually used as one, but there's nothing inherently ephemeral about it. This isn't magic; it's just file I/O.
I understand how the AOF can be considered similar to a postgres WAL file but what makes you say its even more durable?
Forced fsync on every write.
Like a WAL file.
(In its default configuration; there are some unsafe speedups you can do.)
Ability to make RDB snapshots additionally.
Re:Twilio incident and Redis
by VladRussian2 on Wednesday July 24, 2013 @07:25PM
(#6099865)
>Redis will be as durable if not more durable than postgres and the like
guessing by your username where you may be from, you may be aware that freshness... err... durability comes in only one grade - first grade :)