Hi there,
I have problems in understanding the difference between the storage systems. I have read the blog posts, but I do not get it.
Do I need redis when I use timestore?
Why is the data stored in MySQL and Redis simultaneously?
Thanks
Julia
Understanding Redis, timestore und MySQL
Submitted by Guest on Thu, 16/01/2014 - 15:46»
Re: Understanding Redis, timestore und MySQL
Hello Julia, The important point is that redis isnt (yet) being used to store historical data, the only thing redis stores is meta data such as the last time a feed was updated and the last value of that feed. This is used to create the feed list interface and for some of the calculations in input processing. The metadata that doesn't change every 5-10s so things like the feed's name and its id is simultaneously stored in redis and mysql. Its stored in mysql for persistence and redis for quick access (caching).
Before redis the last time and value of a feed was written to a mysql table and resulted in updates to the harddisk every time with redis the last value and time is just stored in memory which is faster.
The feed engines: Timestore, phptimeseries and mysqltimeseries have a different purpose, that is to store historical data for creating graph's over time.
Im not sure if I have explained that very well, let me know if I can elaborate.
Re: Understanding Redis, timestore und MySQL
Thanks. It's clearer for me now.
Re: Understanding Redis, timestore und MySQL
Thanks. I was playing around a little bit and things got easier now.