Questions tagged [redis]

open-source, networked, in-memory, key-value data store

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29
votes
3answers
22k views

How to implement a message queue over Redis?

Why Redis for queuing? I'm under the impression that Redis can make a good candidate for implementing a queueing system. Up until this point we've been using our MySQL database with polling, or ...
24
votes
1answer
15k views

Redis vs Zookeeper

It seems silly to compare these two servers considering that they're meant for very different things. But if you think about it, they can do lots of similar things: store configuration data, ...
5
votes
2answers
3k views

Why is Redis called an in memory database when it provides persistence?

I would like to understand why is redis called an in memory database when it provides persistence similar to databases like MySQL or Postgres: http://oldblog.antirez.com/post/redis-persistence-...
4
votes
2answers
3k views

Redis strategy for activity log data

Our application requires an activity log of actions that a user has done. For example: 3/19/2013 ------------- 9:37 AM Chuck Norris scrapped 3 robots. 9:15 AM Chuck Norris fought 3 robots. ...
4
votes
1answer
558 views

Managing setTimeouts and setInterval in a distributed environment

I am building a turnbased game on nodejs using socket.io and redis as the datastore. I am planning on hosting the game on AWS opsworks with the ability to scale by adding more nodes. How should I ...
3
votes
4answers
1k views

Are NoSQL databases the best choice for more efficiently querying large amounts of data?

We are planning to build a travel website in which we will be integrating multiple APIs (eg. DOTW, GTA, Expedia) for Hotels. I have initially tried to use MySQL but since there are huge amounts of ...
3
votes
1answer
2k views

Microservices - sharing data through distributed in-memory cache?

I'm fairly new to both microservices and shared in-memory databases like Redis. I'm wondering though if it would be a good idea to combine the two to address the challenges of data duplication, ...
3
votes
1answer
226 views

Is my use case for Redis appropriate?

I'm writing a web app that is basically facebook events, but more impromptu and real time. A user can create an event, and other online users in the area (30 mile radius) should immediately see the ...
3
votes
1answer
1k views

Querying key/value store

I don't know whether this question is reasonably answerable (and therefore will be closed), but I will take my chances: What are the possible problems (and solutions), one might encounter, when ...
3
votes
1answer
398 views

Distributing work between TCP Clients

I have an application (run by a Windows Service) which connects to a TCP server (let's call the service 'Listener' from here on). [It's important to note that the TCP server is out of my reach, and ...
3
votes
1answer
949 views

How does Redis (or any typical distributed cache) handle replication conflicts?

Suppose you set up a Redis cluster with one master and two slaves. Two clients are connected to each of the slaves. Both clients make conflicting changes at the same time: What happens if these ...
3
votes
0answers
226 views

Redis set of sets - Is there a better Design?

I have a telegram bot that alerts whenever a price of certain asset reach a certain price. I have the following table in a DB: AlertId ChatId Price Asset So each Asset will have several ChatId (...
3
votes
0answers
1k views

How to tell SignalR Notifications Hub that there is a new notification without having SignalR poll on that table

I'm developing a push-notifications system for my ASP.NET MVC app. The idea is to use Redis for queueing, ServiceStack for queue processing and SignalR for push-notifications to implement a system ...
2
votes
3answers
489 views

Different Redis instances for different microservices?

Say that we have Kubernetes running with n pods, each being a separate microservice. Now, some of those services need a caching layer. When we take into consideration: the fact that Redis was tested ...
2
votes
1answer
3k views

Redis strategy for cache item dependency

I'm implementing cache structure using Redis, my domain is like this: There are multiple categories (3000+ categories). Each category contains multiple questions (around 20-30 questions per category)....
2
votes
1answer
1k views

How would you use Redis for Exception Handling?

I was reading this transcript of an interview with a GitHub developer and he was describing how they use Redis: Q: You mentioned using Redis. How do you use that? A: We use Redis for exception ...
2
votes
1answer
89 views

How is caching used within messaging apps?

I'm actually studying about web development. I was just asking why a lot of web apps and chats(Whatsapp, Telegram, Discord, and a lot, a lot more!) are using cache. I mean, after learning cache ...
2
votes
1answer
182 views

How to think about queries in NoSQL

I'm writing a project for school - Tinder-like app. I thought of implementing database entirely in RDBMS (PostgreSQL). But now I think it's a good opportunity to get to know NoSQL systems a bit. I'm ...
2
votes
1answer
160 views

How to better scale reads in a website: to CQRS or not to CQRS?

The company i'm working for it's rewriting a legacy web application and we are evaluating the better architecture to get the job done. The business domain is quite simple: there are few entities, ...
2
votes
2answers
264 views

Web App Authentication's Architecture Related Query

I have a web app that makes use of node.js in the backend and angulajs on the front end. Let's say I have a user who has the ability to login via multiple systems; I must allow multiple logins. I ...
2
votes
1answer
1k views

how to store online status

I'm developing realtime web chat using pubsub pattern. To be concrete I'm using python and tornado-redis on back end and websockets (WS) (tornado) on front end. I have WS connection open and close ...
2
votes
1answer
249 views

In-memory DB to perform intersects on set slices

I have a specific programming need where I need to efficiently store large sorted sets in memory, query them for ranges, and intersect them against other sets that are also queried for ranged. I am ...
2
votes
1answer
223 views

Semi-securely storing data in a remote key-value store, ensuring minimal data corruption/tampering

I'm bashing around a few ideas for storing usage data (similar to google analytics) for some Javascript products that we are working on. Unfortunately as yet we don't quite know 100% what data we ...
2
votes
0answers
140 views

Using distributed locks in microservice environment

I'm developing distributed system and trying to use best practices of microservice architecture. I was faced with a situation when I think I need something like distributed locks. Since I have not so ...
2
votes
0answers
919 views

How should I store user activities in ElasticSearch and figure out popular searches?

I've got java logging user activities to Fluentd, Fluentd is then writing these activities into an elasticsearch index. Every user activity is recorded, some include: User1 follows user2 User1 likes ...
2
votes
1answer
6k views

Best strategy for storing static data : json file vs DB (mongo) vs redis [closed]

I'm currently designing a set of webservices related to travel industry. one of this service need to be take in input a airport code and a locale, and return the localized city name. fn(cityCode) =&...
2
votes
0answers
298 views

Scoring algorithm implementation with Django and Redis

I use DjangoREST & MySQL as a backend for a mobiel app. I have two models, User and Feed and for any call to api/feeds/ returns all feeds for authenticated user ordered by created_at parameter of ...
1
vote
1answer
572 views

Should I partition my messages with channels or with content?

I'm building a system using redis as a pub-sub system. I'm thinking about ways to represent multiple groups that clients can subscribe to. I could do this with one channel per group, but this could ...
1
vote
1answer
292 views

Exploiting Apache Spark Data

and sorry if the question seems a bit naive. I'm currently reading tutorials about Kafka & Spark and there's something I can't figure out : how to exploit / expose the data Spark received. Here'...
1
vote
1answer
260 views

How to implement searchable persistent queues?

We will implement a system , which will receive quite a lot of requests through web service interface. We will have to queue the requests and process them asynchronously. Consequently we will have to ...
1
vote
1answer
577 views

Redis for caching

I've heard a lot of positive about Redis but have not used it myself. Now I want to add a cache layer for my web app to reduce the DB load, and I suppose Redis is fine for this. But I don't clearly ...
1
vote
1answer
509 views

What is the best way to store short-lived data? [closed]

I have to save some data about users with their location. This data will only be valid for like 5-10 minutes, then it will never be used again. So I am having a simple data structure like: { ...
1
vote
1answer
486 views

2 Servers 1 Database - Can I use Redis?

Ok I have a couple of questions here. First let me give you some background information. I'm starting a project where I have a node.js server running my application and my website running on another ...
1
vote
1answer
202 views

How to architect master/slave store/messages and de-duplication?

To clarify, as I'm not entirely sure how to summarise in the title. I have a redis cluster and a redis-backed scheduler (similar to sidekiq/resque, etc). My redis cluster has a master and a couple ...
1
vote
3answers
1k views

Is it ok to wrap a singleton?

I'm using SignalR with StackExchange Redis. What I gather from the basic usage doc is the way to implement this is using a singleton. I've never used this patter before. My class looks like this: ...
1
vote
2answers
102 views

Creating fast, realtime dialogue search for television scripts

We have a database of television scripts and we'd like to search it, getting results as we type. We often remember words or snippets of dialogue but can't remember exactly what was said or what ...
1
vote
1answer
1k views

What is a good practice to push notifications in a “near real-time” delay in this case?

I want to enable some real-time notifications about friend's activities (social network). Technical context is: Webapp calling backend (REST API's). Scenario is: Kevin follows Bob. When Bob ...
1
vote
1answer
1k views

Storing primary keys of objects in Redis and then querying them in Postgres through Django

This is probably my second time posting in programmers. I'm usually on stackoverflow but this question is more fit for the community here. All suggestions, advice and insight on this matter is ...
1
vote
0answers
28 views

Event Sourcing & Redis

I'm using StackExchange.Redis library, it seems perfect. Hard-coded events related BankAccount with ID 1: // UNSORTED COLLECTION public static List<Event> DomainEvents = new List<Event>()...
1
vote
1answer
226 views

Pros and Cons of using ASPNET.Core In-Memory Caching instead of Redis? [closed]

I know redis is a very robust caching solution and scales great, but when it comes to simpler non-enterprise websites I feel as if it's a bit too expensive (Azure Standard/C1: $100/m). I'm ...
0
votes
1answer
81 views

How to solve cache eviction when not using distributed cache in microservices?

Let's say we will not use distributed caching because we want that our microservices are independent and they do not have many single point of failures. Either we will have in-memory cache (simple ...
0
votes
1answer
88 views

Architecture for distributed real time traffic capturing/viewer system

I have a scenario as following (you can think of it as a distributed Wireshark system): For a single capturing session, there are about 1 ~ 10 traffic capturing nodes distributed in a LAN network. ...
0
votes
2answers
456 views

Algorithm for searching a domain name in list of wildcard

I have a list of domain name that contains wildcard ('*' character) Example: *.google.com *.domain.com ... It contains nearly 1 million domains. The data will be stored on a mongodb or redis ...
0
votes
1answer
607 views

Redis & MongoDB for Metrics Platform

I'm in the process of writing an app that will ultimately display analytics to the user. I've written a service that collects data from an API. This data will then be processed, stored, then when the ...
0
votes
1answer
93 views

Robust locking mechanism between n service instances

I have a job that runs every hour. There can be n identical Node.js microservices running in a stack. The job must be executed only once per hour, though, so I've implemented the following locking ...
0
votes
1answer
115 views

Where should I store statistics about sent emails?

my application sends a batch of custom emails every day using mailgun (an email API service). I have a producer worker scheduled to run daily, and all does is query the database for the unique ...
0
votes
1answer
113 views

Removing Redis Entries from Multiple Redis Instances

I have an interesting problem that I'd like to solve. Let's say I have 2 deployments, US Data Center and Europe Data Center each containing Web Servers and a Redis Instance (replicated, but could ...
0
votes
1answer
148 views

What is the meaning of sharing state between processes?

The author here states that: Share state between processes. Run a long running batch job in one Python interpreter (say loading a few million lines of CSV in to a Redis key/value lookup table) and ...
0
votes
1answer
3k views

Knowing who is the user in every request (every action, every view, every time)

I have many model classes that are mapped from/to tables using EF. Two of them are User and UserCookie, which are stored in tables Users and UserCookies. public class User { public long UserId { ...
0
votes
1answer
1k views

Should I persist notification before or after publishing it through Redis pub/sub?

I'm implementing a mechanism to notify a group of users about newly inserted blog comments. The architecture uses the Redis Pub/Sub mechanism. By definition, the pub/sub mechanism aims to propagate ...