deep dive info about persistancy

[Guy Lubovitch]

Hi,

I have been trying to study how to set persistency in Redis, i plan to have different instances with different requirements and want to understand the two option Redis provide (RDB and AOF).

I read the book Instant Redis Persistence, this book seem a bit out of data even though its pretty new. is there another book or documentation that is elaborate enough?

thank.

[Josiah Carlson]

http://redis.io/topics/persistence

The first part of chapter 4 of Redis in Action is about persistence options, which is freely downloadable on the book's web site: http://manning.com/carlson/ . It only uses about 6 pages to address most of the fundamental persistence options, so is likely brief compared to Matt Palmer's "Instant Redis Persistence", but I think it's a reasonable step from the Redis docs.

 - Josiah

--
You received this message because you are subscribed to the Google Groups "Redis DB" group.
To unsubscribe from this group and stop receiving emails from it, send an email to redis-db+u...@googlegroups.com.
To post to this group, send email to redi...@googlegroups.com.
Visit this group at http://groups.google.com/group/redis-db.
For more options, visit https://groups.google.com/d/optout.

[Guy Lubovitch]

Thanks,

It seem the documentation mostly miss what happen while Redis is doing the save command or write AOF. how much disk space is needed and how much extra memory. maybe also production tuning.

will check your ebook many thanks

[Josiah Carlson]

I cover what goes on during those operations in chapter 4, which you may have already read and understood by now :)

As for properly sizing... that depends on the data. I've seen snapshots vary in size from 1/20th to 1/5 the size of the Redis memory use. If you make an effort, you can get the snapshot to be similar in size, but you have to make an effort for that to be the case.

For AOF, it mostly depends on how many write operations you are performing. An AOF just after BGREWRITEAOF will be of similar size to a snapshot holding the same data, but for every write it receives, it writes that data to disk. How much to provision will depend on your actual data processing requirements, how often you want Redis to perform background rewriting, etc. The best advice I can offer is: test it out with a fraction of what you should reasonably expect, then multiply it out.

 - Josiah