Redis: All content tagged as Redis in NoSQL databases and polyglot persistence
After posting about Spreecast’s Redis High Available/Failover solution based on ZooKeeper where I referred to Redis Sentinel, I realized I haven’t linked to Salvatore Sanfilippo’s post about the design of Redis Sentinel:
It is a distributed monitoring system for Redis. On top of the monitoring layer it also implements a notification system with a simple to use API, and an automatic failover solution.
Well, this is a pretty cold description of what Redis Sentinel is. Actually it is a system that also tries to make monitoring fun! In short you have this monitoring unit, the Sentinel. The idea is that this monitoring unit is extremely chatty, it speaks the Redis protocol, and you can ask it many things about how it is seeing the Redis instances it is monitoring, what are the attached slaves, what the other Sentinels monitoring the same system and so forth. Sentinel is designed to interact with other programs a lot.
The official Redis Sentinel documentation is available too here. Salvatore Sanfilippo is actively working on Redis Sentinel and while it is not complete yet, there are already users trying it out. Redis Sentinel will be stable in a few weeks and will be released as part of the Redis 2.8. In case you’ll want to start using it before 2.8 becomes available, use the git unstable branch
Original title and link: Redis High Availability and Automatic Failover: Redis Sentinel ( ©myNoSQL)
EngineYard’s Ines Sombra recorded a conversation with Mathias Meyer about NoSQL databases and their evolution towards more friendlier functionality, relational databases and their steps towards non-relational models, and a bit more on what polyglot persistence means.
Mathias Meyer is one of the people I could talk for days about NoSQL and databases in general with different infrastructure toppings and he has some of the most well balanced thoughts when speaking about this exciting space—see this conversation I’ve had with him in the early days of NoSQL. I strongly encourage you to download the mp3 and listen to it.
Original title and link: NoSQL and Relational Databases Podcast With Mathias Meyer ( ©myNoSQL)
The top comments on Hacker News about Redis 2.6 RC are about Lua scripting.
Lua scripting! Once people figure out what Redis’ Lua scripting is good for, and it gets in a stable release, it’s going to set the world on fire. In a good way.
When one of the services I work on was having huge performance problems, and nothing I did seemed to make it fast enough, I realized that the main data-manipulation logic — previously a combination of Python and SQL — could be rewritten as a Lua script in Redis. I learned the basics of Lua in about an hour, migrated the data over to Redis, made the necessary changes to the code, and everything worked beautifully. Months of crippling speed problems vanished in a single long day.
Redis 2.6 saved my ass. Now, when I need to store data, it’s always one of the first things to come to mind, since I know I can count on it to be fast, solid, and flexible enough to do all sorts of things.
Going through myNoSQL archives, the first mention of Lua scripting support in Redis is from May 2nd, 2011. Salvatore Sanfilippo already wrote of some advanced functionality that would be possible using it, but I expect many more ideas to come out once Redis 2.6 is released.
Original title and link: Lua Scripting in Redis 2.6 ( ©myNoSQL)
This Apache module uses a rule-based engine (based on regular expression parser) to map URLs to REDIS commands on the fly. It supports an unlimited number of rules and can match on the full URL and the request method (GET, POST, PUT or DELETE) to provide a very flexible option for defining a RESTful interface to REDIS.
Original title and link: Apache Mod_redis ( ©myNoSQL)
Couple of things I don’t see mentioned in the RedMonk post:
if and how data has been normalized based on each connector availability
According to the post data has been collected between Jan.2011-Mar.2012 and I think that not all connectors have been available since the beginning of the period.
if and how marketing pushes for each connectors have been weighed in
Announcing the Hadoop connector at an event with 2000 attendees or the MongoDB connector at an event with 800 attendeed could definitely influence the results (nb: keep in mind that the largest number is less than 7000, thus 200-500 downloads triggered by such an event have a significant impact)
Redis and VoltDB are mostly OLTP only databases
Original title and link: NoSQL Databases Adoption in Numbers ( ©myNoSQL)