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Download the JSON Web Tokens (JWTs) are not safe e-book here Sometimes, people take technologies that are intended to solve a narrow problem and start applying them broadly. The problem may appear similar, but utilizing unique technologies to solve general issues could create unanticipated consequences. To use a metaphor, if you are a hammer, everything looks like a nail. JWT is one such technolog

Click here to get started with Redis Enterprise. Redis Enterprise lets you work with any real-time data at any scale, anywhere. Your scientists were so preoccupied with whether or not they could, they didn’t stop to think if they should.—Dr. Ian Malcolm, in Jurassic Park “Best Practices” has become a trope in technology. Sure, you can do something with a given tool, but is doing so really a good i

Server-assisted, client-side caching in Redis Client-side caching is a technique used to create high performance services. It exploits the memory available on application servers, servers that are usually distinct computers compared to the database nodes, to store some subset of the database information directly in the application side. Normally when data is required, the application servers ask t

It’s that time of the year again. No, I’m not referring to the winter holidays, but to the reverberations of the announcements coming out of AWS re:Invent. Oftentimes when AWS makes a big move, IT ecosystems get shaken. In the database space, this year the effect focused on Apache Cassandra, after AWS announced a Cassandra-compatible serverless managed solution. Along with the announcement, AWS al

JSON support for Redis The JSON capability of Redis Stack provides JavaScript Object Notation (JSON) support for Redis. It lets you store, update, and retrieve JSON values in a Redis database, similar to any other Redis data type. Redis JSON also works seamlessly with Search and Query to let you index and query JSON documents. Primary features Full support for the JSON standard A JSONPath syntax f

Customer case studies Read stories Optimizing Pokémon GO with a Redis Enterprise cluster See more

FAQs Why are you offering a dual license strategy? We believe the permissive approach of RSALv2 and the standard wording we use to define its limitations solves many of the challenges raised by our community, but we are also aware that, like any newly created license, it will take time for some users (and their legal teams) to digest it and therefore we’ve added an option to use SSPL. Created by M

Introduction to Redis streams A Redis stream is a data structure that acts like an append-only log but also implements several operations to overcome some of the limits of a typical append-only log. These include random access in O(1) time and complex consumption strategies, such as consumer groups. You can use streams to record and simultaneously syndicate events in real time. Examples of Redis s

SETNX key value Available since: 1.0.0 Time complexity: O(1) ACL categories: @write, @string, @fast, Set key to hold string value if key does not exist. In that case, it is equal to SET. When key already holds a value, no operation is performed. SETNX is short for "SET if Not eXists". Examples SETNX mykey "Hello" SETNX mykey "World" GET mykey Design pattern: Locking with SETNX Please note that: Th

Searching and querying Redis data Redis Stack offers an enhanced Redis experience via the following search and query features: A rich query language Incremental indexing on JSON and hash documents Vector search Full-text search Geospatial queries Aggregations You can find a complete list of features in the reference documentation. The search and query features of Redis Stack allow you to use Redis

INCR key Available since: 1.0.0 Time complexity: O(1) ACL categories: @write, @string, @fast, Increments the number stored at key by one. If the key does not exist, it is set to 0 before performing the operation. An error is returned if the key contains a value of the wrong type or contains a string that can not be represented as integer. This operation is limited to 64 bit signed integers. Note:

Discovering slow server events in Redis Redis is often used for demanding use cases, where it serves a large number of queries per second per instance, but also has strict latency requirements for the average response time and the worst-case latency. While Redis is an in-memory system, it deals with the operating system in different ways, for example, in the context of persisting to disk. Moreover

Customer case studies Read stories Optimizing Pokémon GO with a Redis Enterprise cluster See more

Building secondary indexes in Redis Redis is not exactly a key-value store, since values can be complex data structures. However it has an external key-value shell: at API level data is addressed by the key name. It is fair to say that, natively, Redis only offers primary key access. However since Redis is a data structures server, its capabilities can be used for indexing, in order to create seco

Overview of Redis key eviction policies (LRU, LFU, etc.) When Redis is used as a cache, it is often convenient to let it automatically evict old data as you add new data. This behavior is well known in the developer community, since it is the default behavior for the popular memcached system. This page covers the more general topic of the Redis maxmemory directive used to limit the memory usage to

SET key value [NX | XX] [GET] [EX seconds | PX milliseconds | EXAT unix-time-seconds | PXAT unix-time-milliseconds | KEEPTTL] Available since: 1.0.0 Time complexity: O(1) ACL categories: @write, @string, @slow, Set key to hold the string value. If key already holds a value, it is overwritten, regardless of its type. Any previous time to live associated with the key is discarded on successful SET o

How transactions work in Redis Redis Transactions allow the execution of a group of commands in a single step, they are centered around the commands MULTI, EXEC, DISCARD and WATCH. Redis Transactions make two important guarantees: All the commands in a transaction are serialized and executed sequentially. A request sent by another client will never be served in the middle of the execution of a Red

How Redis handles common Unix signals This document provides information about how Redis reacts to different POSIX signals such as SIGTERM and SIGSEGV. The information in this document only applies to Redis version 2.6 or greater. SIGTERM and SIGINT The SIGTERM and SIGINT signals tell Redis to shut down gracefully. When the server receives this signal, it does not immediately exit. Instead, it sch

Monitor changes to Redis keys and values in real time Keyspace notifications allow clients to subscribe to Pub/Sub channels in order to receive events affecting the Redis data set in some way. Examples of events that can be received are: All the commands affecting a given key. All the keys receiving an LPUSH operation. All the keys expiring in the database 0. Note: Redis Pub/Sub is fire and forget

A distributed lock pattern with Redis Distributed locks are a very useful primitive in many environments where different processes must operate with shared resources in a mutually exclusive way. There are a number of libraries and blog posts describing how to implement a DLM (Distributed Lock Manager) with Redis, but every library uses a different approach, and many use a simple approach with lowe

SLOWLOG Available since: 2.2.12 Time complexity: Depends on subcommand. ACL categories: @slow, This is a container command for slow log management commands. To see the list of available commands you can call SLOWLOG HELP.

MONITOR Available since: 1.0.0 Time complexity: ACL categories: @admin, @slow, @dangerous, MONITOR is a debugging command that streams back every command processed by the Redis server. It can help in understanding what is happening to the database. This command can both be used via redis-cli and via telnet. The ability to see all the requests processed by the server is useful in order to spot bugs

ZRANGEBYLEX key min max [LIMIT offset count] Available since: 2.8.9 Time complexity: O(log(N)+M) with N being the number of elements in the sorted set and M the number of elements being returned. If M is constant (e.g. always asking for the first 10 elements with LIMIT), you can consider it O(log(N)). ACL categories: @read, @sortedset, @slow, When all the elements in a sorted set are inserted with

SCAN cursor [MATCH pattern] [COUNT count] [TYPE type] Available since: 2.8.0 Time complexity: O(1) for every call. O(N) for a complete iteration, including enough command calls for the cursor to return back to 0. N is the number of elements inside the collection. ACL categories: @keyspace, @read, @slow, The SCAN command and the closely related commands SSCAN, HSCAN and ZSCAN are used in order to i

Build from anywhere Redis Insight is supported on multiple operating systems: Linux, Windows, and macOS. It seamlessly supports all our deployments, whether you use Redis Open Source, Redis Stack, Redis Enterprise Software, Redis Cloud, Amazon ElastiCache, or Azure Cache for Redis. The Redis Insight graphic UI helps you browse and interact with your data. Filter and visualize Redis keys, perform C