question stringlengths 11 28.2k | answer stringlengths 26 27.7k | tag stringclasses 130
values | question_id int64 935 78.4M | score int64 10 5.49k |
|---|---|---|---|---|
How to know status of redis from command line (redis-cli) ? master/slave
| The INFO command returns the current role.
e.g/ if we're the master
role:master
will be shown, amongst other details.
And if we switch to a slave, maybe by using slaveof:
slaveof 192.168.1.66 6379
We get more, when we run INFO:
role:slave
master_host:192.168.1.66
master_port:6379
master_link_status:down
master_last_i... | Redis | 11,307,356 | 51 |
In official docs we can see:
# docker build github.com/creack/docker-firefox
It just works fine to me. docker-firefox is a repository and has Dockerfile within root dir.
Then I want to buid redis image and exact version 2.8.10 :
# docker build github.com/docker-library/redis/tree/99c172e82ed81af441e13dd48dda2729e19493... | docker build url#ref:dir where ref is a branch, a tag, or a commit SHA.
Git URLs accept context configuration in their fragment section,
separated by a colon :. The first part represents the reference that
Git will check out, this can be either a branch, a tag, or a commit
SHA. The second part represents a subdirector... | Redis | 26,753,030 | 50 |
I have a redis server 2.8 installed using ubuntu apt-get on ubuntu 12.04.
I have copied a dump.rdb from an other database. Now when I try to start the new server, I constantly get:
[35763] 04 Mar 01:51:47.088 * 1 changes in 900 seconds. Saving...
[35763] 04 Mar 01:51:47.088 * Background saving started by pid 43313
[433... | You should check your redis.conf file to see the permissions in dir and dbfilename. If the file named in the dbfilename which is located in the path specified in the dir path exists and the permission is also right. then the problem should be fixed.
Hope this will help someone.
P.S.
To find the redis.conf file locatio... | Redis | 22,160,753 | 50 |
I am trying to integrate Redis sessions into my authentication system written in Node.js.
I have been able to successfully set up Redis server, connect-redis and Express server.
Here is my setup (just the important bit):
var express = require("express");
var RedisStore = require("connect-redis")(express);
var redis = r... | That should be all there is to it. You access the session in your route handlers via req.session. The sessions are created, saved, and destroyed automatically.
If you need to manually create a new session for a user, call req.session.regenerate().
If you need to save it manually, you can call req.session.save().
If y... | Redis | 14,014,446 | 50 |
I have 2 services. Both of them need subscribe to the same channel.
The 2 services are load balanced. Each service runs on multiple servers.
So how can I be sure only 1 instance of each service consume the message of that channel.
Is this supported on Redis?
Thanks
| Pubsub doesn't work that way - the message goes to all connected subscribed clients. However, you could set it up so that the channel is a notification of an update to a list. That way all clients will get the message, but only one can take the item from the list with LPOP.
| Redis | 7,196,306 | 50 |
I want to be able to delete all the keys. Is there a way to flush all in node redis?
Redis client:
client = redis.createClient(REDIS_PORT, REDIS_HOST);
| Perhaps flushdb or flushall are options that you can look into.
In Node, with the client, these look like this:
client.flushdb( function (err, succeeded) {
console.log(succeeded); // will be true if successfull
});
| Redis | 37,866,554 | 49 |
I have a question - lookup of a key value pair in an index - let's say on cassandra or postgres - is typically at around O(logn)
source: https://github.com/tinkerpop/blueprints/wiki/Graph-Indices.
In the redis documentation it states that runtime complexity is O(1).
Source: http://redis.io/commands/get
http://redis.... | Redis is an in-memory store. It can therefore use data structures which are adapted to memory storage (allowing for fast random access).
To implement dictionaries (used for the main dictionary, but also for hash and set objects, and in conjunction with a skip list for zset objects), Redis use separate chaining hash tab... | Redis | 15,216,897 | 49 |
Why does Redis use integer database numbers instead of strings? It seems like it would be trivial to keep a small internal data structure which maps strings to the “actual” integer.
| the reason why Redis does not use strings as DB names but indexes is that the goal and ability of Redis databases is not to provide an outer level of dictionary: Redis dictionaries can't scale to many dictionaries, but just to a small number (it is a tradeoff), nor we want to provide nested data structures per design, ... | Redis | 6,618,291 | 49 |
Leveldb seems to be a new interesting persistent key value store from Google. How does Leveldb differ from Redis or Riak or Tokyo Tyrant? In what specific use cases is one better than the other?
| I only add this because in both of the previous answers I don't see this (important) distinction made...
Redis: Is a database server. You communicate with it via a custom binary protocol (via client library typically).
LevelDB: Is a library that implements a key-value store. You communicate with it by calling the C++ ... | Redis | 6,101,402 | 49 |
Setup:
I have a virtual machine and in the virtual machine running three containers (an nginx proxy, a very minimalistic flask app and redis). Flask should be serving on port 5000 while redis on 6379.
Each of these containers are up and running just fine as stand a lone services, but also available via docker compose a... |
In the flask app I have a function that tries to create a redis client
db = redis.Redis(host='localhost', port=6379, decode_responses=True)
When your flask process runs in a container, localhost refers to the network interface of the container itself. It does not resolve to the network interface of your docker host.... | Redis | 54,965,291 | 48 |
The Redis startup script is supposed to create a pid file at startup, but I've confirmed all the settings I can find, and no pid file is ever created.
I installed redis by:
$ yum install redis
$ chkconfig redis on
$ service redis start
In my config file (/etc/redis.conf) I checked to make sure these were enabled:
da... | For those experiencing on Debian buster:
Editing
nano /etc/systemd/system/redis.service
and adding this line below redis [Service]
ExecStartPost=/bin/sh -c "echo $MAINPID > /var/run/redis/redis.pid"
It suppose to look like this:
[Service]
Type=forking
ExecStart=/usr/bin/redis-server /etc/redis/redis.conf
ExecStop=/bi... | Redis | 25,515,166 | 48 |
I wanted to create a redis cache in python, and as any self respecting scientist I made a bench mark to test the performance.
Interestingly, redis did not fare so well. Either Python is doing something magic (storing the file) or my version of redis is stupendously slow.
I don't know if this is because of the way my co... | This is an apples to oranges comparison.
See http://redis.io/topics/benchmarks
Redis is an efficient remote data store. Each time a command is executed on Redis, a message is sent to the Redis server, and if the client is synchronous, it blocks waiting for the reply. So beyond the cost of the command itself, you will p... | Redis | 12,868,222 | 48 |
Somebody asked me what PubSub was and how to create a channel (in comment from my answer) and I pointed him to the article on redis.io => http://redis.io/topics/pubsub. I think it is pretty clear, but I am wondering if somebody has a better explanation. Ideally, describe it clearly using redis-cli.
| Publish/subscribe is a pretty simple paradigm. Think of it like you're running a talk show on a radio station. That's PUBLISH. You're hoping at least one or more people will pick up your channel to listen to your messages on the radio show (SUBSCRIBE) and maybe even do some stuff, but you're not talking to folks dir... | Redis | 6,487,394 | 48 |
Is there a way I can flush my redis db using redis?
I'm looking for something like redis.flushdb() or redis.flushall()
| Redis-py actually has this functionality:
import redis
r = redis.Redis()
r.flushdb()
| Redis | 45,916,183 | 47 |
I just built the redis docker instance
$ docker pull redis
After which I ran it like this.
$ docker run --name=redis --detach=true --publish=6379:6379 redis
I get the following
$ docker ps
key redis "/sbin/entrypoint.sh" 22 minutes ago Up 22 minutes 0.0.0.0:6379->6379/tcp redis
To me the a... | You need to provide more information about your environment (OS, Docker installation, etc), but basically, if you start your Redis container like this:
docker run --name=redis-devel --publish=6379:6379 --hostname=redis --restart=on-failure --detach redis:latest
It should expose the port no matter what. The only reason... | Redis | 33,675,914 | 47 |
I'm using redis lists and pushing to new items to a list. The problem is I really only need the most recent 10 items in a list.
I'm using lpush to add items to a list and lrange to get the most recent 10.
Is there anyway to drop items after a certain number? I'll end up with lists that may have 1,000's of items and ... | After every lpush, call ltrim to trim the list to 10 elements
See http://redis.io/commands/ltrim
| Redis | 12,060,004 | 47 |
By "durable" I mean, the server can crash at any time, and as long as the disk remains in tact, no data is lost (see ACID). Seems like that's what journaling mode is for, but if you enable journaling, doesn't that defeat the purpose of operating on in-memory data? Read operations might not be affected by journaling, bu... | Redis is not usually deployed as a "durable" datastore (in the sense of the "D" in ACID.), even with journaling. Most use cases intentionally sacrifice a little durability in return for speed.
However, the "append only file" storage mode can optionally be configured to operate in a durable manner, at the cost of perfo... | Redis | 2,449,969 | 47 |
I'm switching over from a heroku addon to a direct redis cloud account and am a bit puzzled on how to generate the redis url with the auth info.
The old heroku add-on url was in the format of redis://rediscloud:mypassword@redis...
However in the dashboard and documentation I don't see any mention of a username to go al... | I use golang (https://github.com/garyburd/redigo) and connect to aliyun cloud Redis (link: https://www.aliyun.com/product/kvstore?spm=5176.8006303.267657.7.cW2xH)
By the connect string:
redis://arbitrary_usrname:password@ipaddress:6379/0
when 0 is the database index and success
| Redis | 44,344,628 | 46 |
I am trying to find out values stored in a list of keys which match a pattern from redis. I tried using SCAN so that later on i can use MGET to get all the values, The problem is:
SCAN 0 MATCH "foo:bar:*" COUNT 1000
does not return any value whereas
SCAN 0 MATCH "foo:bar:*" COUNT 10000
returns the desired keys.
How ... | With the code below you will scan the 1000 first object from cursor 0
SCAN 0 MATCH "foo:bar:*" COUNT 1000
In result, you will get a new cursor to recall
SCAN YOUR_NEW_CURSOR MATCH "foo:bar:*" COUNT 1000
To scan 1000 next object. Then when you increase COUNT from 1000 to 10000 and retrieve data you scan more keys th... | Redis | 33,166,812 | 46 |
I did an package manager update-package command to update our project to the latest binaries. I almost published it because it passed all the tests until luckily I had found a problem that needed some more debugging.
My mouth fell open when I suddenly saw this exception message:
The free-quota limit on '6000 Redis r... | We are migrating to Booksleeve, which was developed by the people who have built StackOverflow itself. So far we had very good experiences.
The money is not the issue (the cost of migration is higher than paying for the license), we're doing it because we just don't want to enter a business relationship with company wi... | Redis | 20,785,419 | 45 |
I have JSON (<1k) to store in Redis through node.js. What are the pros and cons of storing it as an object or string? Are there other options I missed? All processing will ultimately happen on the client side, so converting into an object is not necessary.
SET
var images = JSON.parse(data); // data is already... | You can store JSON in redis either as a plain string in dedicated key (or member/value of a set/list) or in a hash structure. If you look at node_redis docs into Friendlier hash commands part you'll see that it gives you some useful methods for manipulating JSON based data. Pros of this approach is that it allows you t... | Redis | 8,986,982 | 45 |
I can't find anywhere online what is default TTL in Redis.
I know that I can set TTL for specific SET, but don't know what is default TTL.
Can someone tell me what default time to live is in Redis?
| There is no default TTL. By default, keys are set to live forever.
| Redis | 49,133,314 | 44 |
I'm building an application with ExpressJS, Mongodb(Mogoose). Application contains routes where user has to be authenticated before accessing it.
Currently I have written a express middleware to do the same. Here with the help of JWT token I'm making mongodb query to check whether user is authenticated or not. but feel... | TLDR: If you want the capability to revoke a JWT at some point, you'll need to look it up. So yes, something fast like Redis can be useful for that.
One of the well documented drawbacks of using JWTs is that there's no simple way to revoke a token if for example a user needs to be logged out or the token has been compr... | Redis | 44,890,564 | 44 |
I Installed Redis Server on ubuntu 16.04. but when I try to start the redis service using
$ sudo systemctl start redis
I receive message:
Failed to start redis.service: Unit redis-server.service is masked.
I don't have any idea about this error.
| I found the solution. I think it will help for others
| systemctl unmask servicename
$ sudo systemctl unmask redis-server.service
| Redis | 40,317,106 | 44 |
The Setup:
Imagine a 'twitter like' service where a user submits a post, which is then read by many (hundreds, thousands, or more) users.
My question is regarding the best way to architect the cache & database to optimize for quick access & many reads, but still keep the historical data so that users may (if they want... | It is actually sensible to associate Redis and MongoDB: they are good team players. You will find more information here:
MongoDB with redis
One critical point is the resiliency level you need. Both Redis and MongoDB can be configured to achieve an acceptable level of resiliency, and these considerations should be discu... | Redis | 11,218,941 | 44 |
How do you use the node.js redis library, what are the core concepts of redis and what does all the redis functions do, e.g. hset, hget etc? Could I have some example.
|
How do you use the nodejs redis
library
Check out node_redis and its examples.
what are the core concepts of redis
You should look at redis data types in order to get a bigger picture of its concepts and data types.
what does all the redis functions do
Try to look at this introduction in order to better underst... | Redis | 5,656,991 | 44 |
After setting a DataFrame to redis, then getting it back, redis returns a string and I can't figure out a way to convert this str to a DataFrame.
How can I do these two appropriately?
| set:
redisConn.set("key", df.to_msgpack(compress='zlib'))
get:
pd.read_msgpack(redisConn.get("key"))
| Redis | 37,943,778 | 43 |
How to completely disable RDB and AOF?
I don't care about Persistence and want it to be in mem only.
I have already commented out the:
#save 900 1
#save 300 10
#save 60 10000
But this did not help and I see that Redis still tries to write to disk.
I know that Redis wants to write to disk because I get this error: "Fai... | If you want to change the redis that is running, log into the redis, and
disable the aof:
config set appendonly no
disable the rdb:
config set save ""
If you want to make these changes effective after restarting redis, using
config rewrite
to make these changes to redis conf file.
If your redis have not started, jus... | Redis | 27,681,402 | 43 |
I am using Redis with StackExchange.Redis. I have multiple threads that will at some point access and edit the value of the same key, so I need to synchronize the manipulation of the data.
Looking at the available functions, I see that there are two functions, TakeLock and ReleaseLock. However, these functions take bo... | There are 3 parts to a lock:
the key (the unique name of the lock in the database)
the value (a caller-defined token which can be used both to indicate who "owns" the lock, and to check that releasing and extending the lock is being done correctly)
the duration (a lock intentionally is a finite duration thing)
If no ... | Redis | 25,127,172 | 43 |
Could you please explain me following example from "The Little Redis Book":
With the code above, we wouldn't be able to implement our own incr
command since they are all executed together once exec is called. From
code, we can't do:
redis.multi()
current = redis.get('powerlevel')
redis.set('powerlevel', current... | There are several questions here.
1) Why we can't execute increment in transaction that can't be interrupted by other command?
Please note first that Redis "transactions" are completely different than what most people think transactions are in classical DBMS.
# Does not work
redis.multi()
current = redis.get('powerlev... | Redis | 10,750,626 | 43 |
I'm using Redis version 2.2.13
jack@ubuntu:~/redis$ src/redis-server
[23900] 14 Sep 14:28:52 # Warning: no config file specified, using the default config. In order to specify a config file use 'redis-server /path/to/redis.conf'
[23900] 14 Sep 14:28:52 # Opening port: bind: Address already in use
So I follow the above... | I had this same problem, but I forgot that redis persists. If you get this error, try this command:
redis-cli ping
if you get PONG as a response, then Redis is running, and the port is in use, by Redis.
| Redis | 7,417,232 | 43 |
I want an autocomplete feature. I have short descriptive strings on a
property of a data type. I have a list of ids in redis for the
datatype ordered by created date and I use the ids to set and get
properties for the datatype as explained in the redis type
documentation. I don't use hash tables. What's the best wa... | You need to set up an index using sets or sorted sets that you write to when you save anything.
There's a good writeup at http://web.archive.org/web/20121013063245/http://playnice.ly/blog/2010/05/05/a-fast-fuzzy-full-text-index-using-redis that is pretty close to what I use myself.
| Redis | 6,401,194 | 43 |
If a user is already logged in and tries to login again in a new instance I'd like it to log out the other user instance. I don't want the same user to be logged in twice on my application.
Currently the session is stored in a Redis store, i'm using express / connect to handle the session storage. One of the functions ... | req.sessionID will provide you the session's ID, where req is a request object.
| Redis | 9,291,548 | 42 |
I'm using Resque on a rails-3 project to handle jobs that are scheduled to run every 5 minutes. I recently did something that snowballed the creation of these jobs and the stack has hit over 1000 jobs. I fixed the issue that caused that many jobs to be queued and now the problem I have is that the jobs created by the b... | Playing off of the above answers, if you need to clear all of your queues, you could use the following:
Resque.queues.each{|q| Resque.redis.del "queue:#{q}" }
| Redis | 5,880,962 | 42 |
What are the strengths and weaknesses of the various NoSQL databases available?
In particular, it seems like Redis is weak when it comes to distributing write load over multiple servers. Is that the case? Is it a big problem? How big does a service have to grow before that could be a significant problem?
| The strengths and weaknesses of the NoSQL databases (and also SQL databases) is highly dependent on your use case. For very large projects, performance is king; but for brand new projects, or projects where time and money are limited, simplicity and time-to-market are probably the most important. For teaching yourself ... | Redis | 4,720,508 | 42 |
In Redis 4.0, there is a new command UNLINK to delete the keys in Redis memory.
This command is very similar to DEL: it removes the specified keys.
Just like DEL a key is ignored if it does not exist. However the
command performs the actual memory reclaiming in a different thread,
so it is not blocking, while D... | Before discussing which one is better, let's take a look at the difference between these commands. Both DEL and UNLINK free the key part in blocking mode. And the difference is the way they free the value part.
DEL always frees the value part in blocking mode. However, if the value is too large, e.g. too many allocatio... | Redis | 45,818,371 | 41 |
I have done simple performance test on my local machine, this is python script:
import redis
import sqlite3
import time
data = {}
N = 100000
for i in xrange(N):
key = "key-"+str(i)
value = "value-"+str(i)
data[key] = value
r = redis.Redis("localhost", db=1)
s = sqlite3.connect("testDB")
cs = s.cursor()
... | from the redis documentation
Redis is a server: all commands involve network or IPC roundtrips. It is meaningless to compare it to embedded data stores such as SQLite, Berkeley DB, Tokyo/Kyoto Cabinet, etc ... because the cost of most operations is precisely dominated by network/protocol management.
Which does make s... | Redis | 11,216,647 | 41 |
The Redis service is available on my hosting, and if i connect it for money, it is available only for me, since Redis rises in a separate docker container.
But, if i turn it off, then Redis can still be used for free, though server-wide. And here I am connecting to the server-wide Redis:
$redis = new Redis ();
$redis->... | This hosting provider is responsible for the security breach. Considering OWASP's top ten Web application security risks, this is an issue of few security risks: Broken Authentication, Sensitive Data Exposure, and Broken Access Control.
What is your next step is up to you. You should inform the hosting provider, users... | Redis | 60,477,527 | 40 |
Can anyone help me install php-redis in MAC OSX .
brew install php-redis
not working.
pecl install php-redis
also not working getting -
invalid package name/package file "php-redis".
Homebrew Error:
homebrew_error
| git clone https://www.github.com/phpredis/phpredis.git
cd phpredis
phpize && ./configure && make && sudo make install
Add extension=redis.so in your php.ini
brew services restart php@7.2
make test
You can check working or not
php -r "if (new Redis() == true){ echo \"\r\n OK \r\n\"; }"
| Redis | 51,908,004 | 40 |
When calling Lua scripts from within Redis, it is possible to pass values in two arrays: KEYS and ARGV. What is the difference? How does Redis treat values in the KEYS array? What if, in my script, I have to use keys dynamically generated at run time?
| All your questions are answered at the EVAL page, but since you asked...:
What is the difference?
KEYS is used to pass key names whereas ARGS should be for anything else. This isn't exactly enforced (i.e. most times you'd be ok mixing them) but could lead to potential problems if not followed.
How does Redis treat ... | Redis | 32,089,406 | 40 |
I have installed redis using sudo apt-get install redis-server command but I am receiving this error when I run my Python program:
ImportError: No module named redis
Any idea what's going wrong or if I should install any other package as well? I am using Ubuntu 13.04 and I have Python 2.7.
| To install redis-py, simply:
$ sudo pip install redis
or alternatively (you really should be using pip though):
$ sudo easy_install redis
or from source:
$ sudo python setup.py install
Getting Started
>>> import redis
>>> r = redis.StrictRedis(host='localhost', port=6379, db=0)
>>> r.set('foo', 'bar')
True
>>> r.get... | Redis | 19,288,900 | 40 |
Question 1:
I know Redis load all the data into memory, thus improving the read/write speed. So, does it mean that if my memory size is 2G, the maximum dataset size should not be larger than 2G? Now my database has a 100G+ data, the memory of my server cannot be larger than 32G, so, Redis is no longer suitable for me?
... | Regarding question 1, Redis is an in-memory store with some persistency capabilities. All your dataset should fit in memory. A single instance is therefore limited by the maximum memory of your server. Now, you can also shard the data to several Redis instances, running on multiple servers. Provided you have the budget... | Redis | 18,376,665 | 40 |
My team has decided to work with Redis via the ServiceStack.net Redis Client as an underlying repository for a new high-volume website we're working on. I'm not really sure where to look for documentation for this question (either for general Redis docs or specific ServiceStack.Net docs or both) - is there actually a d... | Rather than re-hash a lot of other documentation that's out there in the wild, I'll list a couple around for some background info around Redis + ServiceStack's Redis Client:
What to think about when designing a NoSQL Redis application
Designing a NoSQL Database using Redis
General Overview of Redis and .NET
Schemaless... | Redis | 8,914,349 | 40 |
Here is my code using socket.io as WebSocket and backend with pub/sub redis.
var io = io.listen(server),
buffer = [];
var redis = require("redis");
var subscribe = redis.createClient(); **<--- open new connection overhead**
io.on('connection', function(client) {
console.log(client.request.headers.cookie);
... | Actually you are only creating a new redis client for every connection if you are instantiating the client on the "connection" event. What I prefer to do when creating a chat system is to create three redis clients. One for publishing, subscribing, and one for storing values into redis.
for example:
var socketio = requ... | Redis | 5,739,357 | 40 |
How does one upgrade to a newer version of Redis with zero downtime? Redis slaves are read-only, so it seems like you'd have to take down the master and your site would be read-only for 45 seconds or more while you waited for it to reload the DB.
Is there a way around this?
| Redis Team has very good documentation on this
Core Steps:
Setup your new Redis instance as a slave for your current Redis instance. In order to do so you need a different server, or a server that has enough RAM to keep two instances of Redis running at the same time.
If you use a single server, make sure that the sla... | Redis | 4,719,346 | 40 |
The queue:listen was not run on a server, so some jobs were pushed (using Redis driver) but never run.
How could I count (or get all) these jobs? I did not find any artisan command to get this information.
| Since Laravel 5.3 you can simply use Queue::size() (see PR).
| Redis | 35,412,779 | 39 |
I run my Integration Test cases with Spring Boot with the help of my local Redis server on my machine.
But I want an embedded Redis server which is not dependent on any server and can run on any environment, like the H2 in-memory database. How can I do it?
@RunWith(SpringJUnit4ClassRunner.class)
@WebAppConfiguration
@I... | You can use an embedded Redis like https://github.com/kstyrc/embedded-redis
Add the dependency to your pom.xml
Adjust the properties for your integration test to point to your embedded redis, for example :
spring:
redis:
host: localhost
port: 6379
Instanciate the embedded redis server in a component that ... | Redis | 32,524,194 | 39 |
While I was following Azure documentation for how to use Redis Cache in Azure Portal I noticed this note:
If you prefer to use a strong-named version of the StackExchange.Redis
client library, choose StackExchange.Redis.StrongName; otherwise
choose StackExchange.Redis.
What is the strong-named ? and what is the p... | Do you need a strongly named Redis library? In all likelihood, especially if you never even encountered this term, the answer is no. But read on.
What is strongly named?
it's a .NET specific thing
you can choose to sign your assembly with a cryptographic key
this makes it possible to verify that you are actually load... | Redis | 28,584,950 | 39 |
I'm using Celery (3.0.15) with Redis as a broker.
Is there a straightforward way to query the number of tasks with a given name that exist in a Celery queue?
And, as a followup, is there a way to cancel all tasks with a given name that exist in a Celery queue?
I've been through the Monitoring and Management Guide and d... | # Retrieve tasks
# Reference: http://docs.celeryproject.org/en/latest/reference/celery.events.state.html
query = celery.events.state.tasks_by_type(your_task_name)
# Kill tasks
# Reference: http://docs.celeryproject.org/en/latest/userguide/workers.html#revoking-tasks
for uuid, task in query:
celery.control.revoke(u... | Redis | 15,575,826 | 39 |
Pretty simple question. I am building a realtime game using nodejs as my backend and I am wondering if there is any information available on which one is more reliable and which one is more efficient?
I am heavily using both Redis and Socket.io throughout my code. So I want to know whether I should be utilizing Socket.... | Redis pub/sub is great in case all clients have direct access to redis. If you have multiple node servers, one can push a message to the others.
But if you also have clients in the browser, you need something else to push data from a server to a client, and in this case, socket.io is great.
Now, if you use socket.io w... | Redis | 14,929,700 | 39 |
I know if I do redis-cli -h {ip_address} -p {port} I can connect to a specific port/ip but I've set my instance to not listen to any tcp/ip ports instead it listens to local socket.
How can I establish a socket connection with the redis client?
| You can connect from redis-cli or redis-benchmark simply by using the -s option and providing the path of your unix domain socket.
For instance:
redis-cli -s /tmp/redis.sock
redis-benchmark -q -n 10000 -s /tmp/redis.sock
| Redis | 9,445,024 | 39 |
The GitHub guys recently released their background processing app which uses Redis:
http://github.com/defunkt/resque
http://github.com/blog/542-introducing-resque
I have it working locally, but I'm struggling to get it working in production. Has anyone got a:
Capistrano recipe to deploy workers (control number of wor... | I'm a little late to the party, but thought I'd post what worked for me. Essentially, I have god setup to monitor redis and resque. If they aren't running anymore, god starts them back up. Then, I have a rake task that gets run after a capistrano deploy that quits my resque workers. Once the workers are quit, god will ... | Redis | 1,732,415 | 39 |
I am a little bit lost. I am reading Microsoft documentation for ASP.NET Core caching using Redis.
And the documentation suggests to use Microsoft.Extensions.Caching.StackExchangeRedis which is an open source third party library.
But I've seen some other tutorials are using Microsoft.Extensions.Caching.Redis, which is ... | A look at the dependency graph for Microsoft.Extensions.Caching.Redis and Microsoft.Extensions.Caching.StackExchangeRedis reveals it.
Microsoft.Extensions.Caching.Redis is based on StackExchange redis 1.x library, whereas Microsoft.Extensions.Caching.StackExchangeRedis is based on 2.x of the same library.
Also Microsof... | Redis | 59,847,571 | 38 |
I've been asked to evaluate RabbitMQ instead of Kafka but found it hard to find a situation where a message queue is more suitable than Kafka. Does anyone know use cases where a message queue fits better in terms of throughput, durability, latency, or ease-of-use?
| RabbitMQ is a solid, general-purpose message broker that supports several protocols such as AMQP, MQTT, STOMP, etc. It can handle high throughput. A common use case for RabbitMQ is to handle background jobs or long-running task, such as file scanning, image scaling or PDF conversion. RabbitMQ is also used between micro... | RabbitMQ | 42,151,544 | 546 |
I am new to message brokers like RabbitMQ which we can use to create tasks / message queues for a scheduling system like Celery.
Now, here is the question:
I can create a table in PostgreSQL which can be appended with new tasks and consumed by the consumer program like Celery.
Why on earth would I want to setup a whol... | Rabbit's queues reside in memory and will therefore be much faster than implementing this in a database. A (good)dedicated message queue should also provide essential queuing related features such as throttling/flow control, and the ability to choose different routing algorithms, to name a couple(rabbit provides these ... | RabbitMQ | 13,005,410 | 268 |
How can I delete all pending tasks without knowing the task_id for each task?
| From the docs:
$ celery -A proj purge
or
from proj.celery import app
app.control.purge()
(EDIT: Updated with current method.)
| RabbitMQ | 7,149,074 | 249 |
I am just starting to use RabbitMQ and AMQP in general.
I have a queue of messages
I have multiple consumers, which I would like to do different things with the same message.
Most of the RabbitMQ documentation seems to be focused on round-robin, ie where a single message is consumed by a single consumer, with the lo... | Can I have each consumer receive the same messages? Ie, both consumers get message 1, 2, 3, 4, 5, 6? What is this called in AMQP/RabbitMQ speak? How is it normally configured?
No, not if the consumers are on the same queue. From RabbitMQ's AMQP Concepts guide:
it is important to understand that, in AMQP 0-9-1, message... | RabbitMQ | 10,620,976 | 240 |
The RabbitMQ Java client has the following concepts:
Connection - a connection to a RabbitMQ server instance
Channel - ???
Consumer thread pool - a pool of threads that consume messages off the RabbitMQ server queues
Queue - a structure that holds messages in FIFO order
I'm trying to understand the relationship, and ... |
A Connection represents a real TCP connection to the message broker, whereas a Channel is a virtual connection (AMQP connection) inside it. This way you can use as many (virtual) connections as you want inside your application without overloading the broker with TCP connections.
You can use one Channel for everything.... | RabbitMQ | 18,418,936 | 237 |
I've installed the latest RabbitMQ server (rabbitmq-server-3.3.0-1.noarch.rpm) on a fresh Centos 5.10 VM according to the instructions on the official site.
I've done this many times before during development and never had any issues. However, this time I cannot log into the management web interface using the default g... | It's new features since the version 3.3.0
http://www.rabbitmq.com/release-notes/README-3.3.0.txt
server
------
...
25603 prevent access using the default guest/guest credentials except via
localhost.
If you want enable the guest user read this or this RabbitMQ 3.3.1 can not login with guest/guest
# remove gues... | RabbitMQ | 22,850,546 | 230 |
I installed rabbitmqadmin and was able to list all the exchanges and queues. How can I use rabbitmqadmin or rabbitmqctl to delete all the queues.
| First, list your queues:
rabbitmqadmin list queues name
Then from the list, you'll need to manually delete them one by one:
rabbitmqadmin delete queue name='queuename'
Because of the output format, doesn't appear you can grep the response from list queues. Alternatively, if you're just looking for a way to clear ever... | RabbitMQ | 11,459,676 | 227 |
How do I delete all messages from a single queue using the cli?
I have the queue name and I want to clean it.
| you can directly run this command
sudo rabbitmqctl purge_queue queue_name
| RabbitMQ | 5,313,027 | 183 |
How can I verify which version of rabbitmq is running on a server?
Is there a command to verify that rabbitmq is running?
| Use this command:
sudo rabbitmqctl status
and look for line that looks like this:
{rabbit,"RabbitMQ","2.6.1"},
| RabbitMQ | 7,593,269 | 174 |
What ports does RabbitMQ Server use or need to have open on the firewall for a cluster of nodes?
My /usr/lib/rabbitmq/bin/rabbitmq-env is set below which I'm assuming are needed (35197).
SERVER_ERL_ARGS="+K true +A30 +P 1048576 \
-kernel inet_default_connect_options [{nodelay,true}] \
-kernel inet_dist_listen_min ... | PORT 4369: Erlang makes use of a Port Mapper Daemon (epmd) for resolution of node names in a cluster. Nodes must be able to reach each other and the port mapper daemon for clustering to work.
PORT 35197
set by inet_dist_listen_min/max Firewalls must permit traffic in this range to pass between clustered nodes
RabbitMQ ... | RabbitMQ | 12,792,856 | 160 |
I am trying to understand what JMS and how it is connected to AMQP terminology.
I know JMS is an API and AMQP is a protocol.
Here are my assumptions (and questions as well)
RabbitMQ uses AMQP protocol (rather implements AMQP protocol)
Java clients need to use AMQP protocol client libraries to connect / use RabbitMQ
W... | Your question is a bit messy but Let's see its bits one by one.
General concept:
The Java Message Service (JMS) API is a Java Message Oriented Middleware (MOM) API for sending messages between two or more clients. JMS is a part of the Java Platform, Enterprise Edition, and is defined by a specification developed under ... | RabbitMQ | 15,150,133 | 157 |
I'm getting confused between these two types of messages in RabbitMQ.
I've seen that some of my queues have 0 "Unacked" and 1000 "Ready" messages, while some have 1000 "Unacked" and 0 "Ready" messages.
What's the difference between them?
And how can I know how many of the messages are read by the consumer(s)?
| A message is Ready when it is waiting to be processed.
When a consumer connects to the queue it gets a batch of messages to process. The amount is given in the prefetch size. While this consumer is working on the messages they get the status unacked.
Unacked means that the consumer has promised to process them but has ... | RabbitMQ | 31,915,773 | 145 |
I need to create a queue for processing. The queue itself is relatively low-volume. There might be about 1,000 writes to it per hour. The execution of each task might take about a minute each, and are processed almost as soon as the item is added to the queue.
Is there any reason that I might want to implement RabbitMQ... | Here are a few factors to help you decide which one to go for:
RabbitMQ is FIFO by default. Amazon SQS queues can optionally be set to FIFO.
You can setup your own server with RabbitMQ but not in the case of Amazon SQS so the cost gets involved here.
Setting up your own server will require good knowledge of the subj... | RabbitMQ | 28,687,295 | 141 |
I am getting below exception
org.springframework.amqp.AmqpAuthenticationException: com.rabbitmq.client.AuthenticationFailureException: ACCESS_REFUSED - Login was refused using authentication mechanism PLAIN. For details see the broker logfile.
Configuration: RabbitMQ 3.3.5 on windows
On Config file in %APPDATA%\Rabbi... | I am sure what Artem Bilan has explained here might be one of the reasons for this error:
Caused by: com.rabbitmq.client.AuthenticationFailureException:
ACCESS_REFUSED - Login was refused using authentication mechanism PLAIN.
For details see the
but the solution for me was that I logged in to rabbitMQ admin page (... | RabbitMQ | 26,811,924 | 136 |
From my understanding, Celery is a distributed task queue, which means the only thing that it should do is dispatching tasks/jobs to others servers and get the result back. RabbitMQ is a message queue, and nothing more. However, a worker could just listen to the MQ and execute the task when a message is received. This ... | You are right, you don't need Celery at all. When you are designing a distributed system there are a lot of options and there is no right way to do things that fits all situations.
Many people find that it is more flexible to have pools of message consumers waiting for a message to appear on their queue, doing some wor... | RabbitMQ | 9,077,687 | 133 |
This was probably asked already, but so far I can't find any detailed explanation at all, and the existing documentation seems as if it was written for some kind on psychic who supposed to know everything.
As per this manual, I added the container
docker run -d --hostname my-rabbit --name some-rabbit rabbitmq:latest
T... | You are using the wrong image which doesn't have the rabbitmq_management plugin enabled. Change rabbitmq:latest to rabbitmq:management.
On dockerhub they are using the command:
docker run -d --hostname my-rabbit --name some-rabbit rabbitmq:3-management
If you want to go to the UI on localhost:15672 make sure to expose... | RabbitMQ | 47,290,108 | 132 |
We are defining an architecture to collect log information by Logstash shippers which are installed in various machines and index the data in one elasticsearch server centrally and use Kibana as the graphical layer. We need a reliable messaging system in between Logstash shippers and elasticsearch to grantee the delive... | After evaluating both Redis and RabbitMQ I chose RabbitMQ as our broker for the following reasons:
RabbitMQ allows you to use a built in layer of security by using SSL certificates to encrypt the data that you are sending to the broker and it means that no one will sniff your data and have access to your vital organiz... | RabbitMQ | 29,539,443 | 124 |
What is the basic difference between stream processing and traditional message processing? As people say that kafka is good choice for stream processing but essentially kafka is a messaging framework similar to ActivMQ, RabbitMQ etc.
Why do we generally not say that ActiveMQ is good for stream processing as well.
Is it... | In traditional message processing, you apply simple computations on the messages -- in most cases individually per message.
In stream processing, you apply complex operations on multiple input streams and multiple records (ie, messages) at the same time (like aggregations and joins).
Furthermore, traditional messaging ... | RabbitMQ | 41,744,506 | 121 |
Currently i am starting RabbitMQ Docker container using the default RabbitMQ image from DockerHub. Using the following commands.
docker run --restart=always \
-d \
-e RABBITMQ_NODENAME=rabbitmq \
-v /opt/docker/rabbitmq/data:/var/lib/rabbitmq/mnesia/rabbitmq \
-p 5672:5672 \
-p 15672:15672 \
--name rabbitmq rabbitmq:3-... | You can create a simple Dockerfile that extends the functionality of the basic image and creates a default user.
The Docker file you need is the following:
FROM rabbitmq
# Define environment variables.
ENV RABBITMQ_USER user
ENV RABBITMQ_PASSWORD user
ENV RABBITMQ_PID_FILE /var/lib/rabbitmq/mnesia/rabbitmq
ADD init.s... | RabbitMQ | 30,747,469 | 113 |
What are the allowed types of messages (strings, bytes, integers, etc.)?
What is the maximum size of a message?
What is the maximum number of queues and exchanges?
|
Theoretically anything can be stored/sent as a message. You actually don't want to store anything on the queues. The system works most efficiently if the queues are empty most of the time. You can send anything you want to the queue with two preconditions:
The thing you are sending can be converted to and from a b... | RabbitMQ | 18,353,898 | 111 |
Using rabbitmq, we can install management plugin. Then we access via browser using http://localhost:55672/ using guest:guest.
The problem is, I can not login anymore because i changed password and entered blank for role.
Is there any way to reset user for rabbitmq management?
| You can access the user-management with rabbitmqctl and use the command:
add_user {username} {password}
or more preferably maybe edit an existing user, or set the permissions for the new user with:
set_permissions [-p vhostpath] {user} {conf} {write} {read}
For example use the following commands: (it is important to ... | RabbitMQ | 14,699,873 | 107 |
I have a few queues running with RabbitMQ. A few of them are of no use now, how can I delete them? Unfortunately I had not set the auto_delete option.
If I set it now, will it be deleted?
Is there a way to delete those queues now?
| If you do not care about the data in management database; i.e. users, vhosts, messages etc., and neither about other queues, then you can reset via commandline by running the following commands in order:
WARNING: In addition to the queues, this will also remove any users and vhosts, you have configured on your RabbitM... | RabbitMQ | 6,742,938 | 103 |
I am using RabbitMQ and I have a queue that holds email messages. My consumer service de-queues messages and attempts to send them. If, for any reason, my consumer cannot send the message, I would like to re-queue the message to send again.
I realize I can do a basicNack and set the requeue flag to be true, however, I ... | Update from 2023 based on quorum queue's way of poison message handling:
Quorum queues keep track of the number of unsuccessful delivery attempts and expose it in the "x-delivery-count" header that is included with any redelivered message.
They've also added a support of policies to limit re-deliveries:
It is possib... | RabbitMQ | 23,158,310 | 102 |
If I have RabbitMQ installed on my machine, is there a way to create a message queue from the command line and bind it to a certain exchange without using a client?
I think it is not possible, but I want to be sure.
| Summary:
Other answers are good alternatives to what was asked for. Below are commands you can use from the command line.
First, do all the necessary prep work, e.g. install rabbit, rabbitmqadmin, and rabbitctl. The idea is to use commands from rabbitmqctl and rabbitmqadmin. You can see some command examples: https://w... | RabbitMQ | 4,545,660 | 92 |
This seems like a question that should be easily be googleable. It is not though. Can anybody help?
How do I create a new user for rabbitmq?
| I have found this very useful
This adds a new user and password
rabbitmqctl add_user username password
This makes the user a administrator
rabbitmqctl set_user_tags username administrator
This sets permissions for the user
rabbitmqctl set_permissions -p / username ".*" ".*" ".*"
See more here https://www.rabbitmq.co... | RabbitMQ | 40,436,425 | 90 |
I need to choose a new Queue broker for my new project.
This time I need a scalable queue that supports pub/sub, and keeping message ordering is a must.
I read Alexis comment: He writes:
"Indeed, we think RabbitMQ provides stronger ordering than Kafka"
I read the message ordering section in rabbitmq docs:
"Messa... | Well, let's take a closer look at the scenario you are describing above. I think it's important to paste the documentation immediately prior to the snippet in your question to provide context:
Section 4.7 of the AMQP 0-9-1 core specification explains the
conditions under which ordering is guaranteed: messages publishe... | RabbitMQ | 21,363,302 | 89 |
I have RabbitMQ installed and started. The service is running as well. However, when I try to open the management interface in firefox, I get this error:
Firefox can't establish a connection to the server at localhost:#####. (##### being several port numbers i tried).
I checked the ports and made sure that they were c... | I think you should check a few things:
the management plugin is not enabled by default, you need to run the below command to enable it: (see https://www.rabbitmq.com/management.html)
rabbitmq-plugins enable rabbitmq_management
Also this runs on port 15672 by default, it is possible the server/network is blocking this ... | RabbitMQ | 23,500,014 | 83 |
I'm doing real time live web app development.
Browser users should be able to communicate with eachother through a node.js server. One of the user writes a message and all other users will get it.
I don't quite get how RabbitMQ works. But from quick reading it seems that it handles publication/subscription of messages.... | Update
Are there scenarios I need RabbitMQ
for web apps where Socket.io doesn't
suffice?
Browser users should be able to communicate with eachother through a node.js server. One
of the user writes a message and all other users will get it.
When you only have these simple requirements then socket.io alone wi... | RabbitMQ | 6,636,213 | 83 |
I am trying to learn messaging system. I have found that RabbitMq and NServiceBus are using together in few places. My questions are
If I am using the RabbitMQ then why do i need NServiceBus? and vice versa
What NServiceBus can do but RabbitMQ or Kafka cannot?
Can I use NServiceBus and kafka together? Or Apache-Kafka ... | Years ago, I asked myself the same question. I was looking at NServiceBus to work with a different message queue, but the question was the same.
I decided not to use NServiceBus.
6 Month later, I realized I had re-built half of what NServiceBus did... only much more poorly.
The equivalent question of why would you need... | RabbitMQ | 38,103,412 | 82 |
OS: Mac OSX 10.9
I have rabbitmq installed via home brew and when I go to /usr/local/sbin and run rabbitmq-server it states that: rabbitmq-server: command not found even as sudo it states the same error.
How do I get rabbitmq to start if it's not a command? I have also tried chmod +x rabbitmq-server in that directory t... | From the docs:
The RabbitMQ server scripts are installed into /usr/local/sbin. This is not automatically added to your path, so you may wish to add
PATH=$PATH:/usr/local/sbin to your .bash_profile or .profile. The server can then be started with rabbitmq-server.
All scripts run under your own user account. Sudo is n... | RabbitMQ | 23,050,120 | 82 |
My rough understanding is that Redis is better if you need the in-memory key-value store feature, however I am not sure how that has anything to do with distributing tasks?
Does that mean we should use Redis as a message broker IF we are already using it for something else?
| I've used both recently (2017-2018), and they are both super stable with Celery 4. So your choice can be based on the details of your hosting setup.
If you must use Celery version 2 or version 3, go with RabbitMQ. Otherwise...
If you are using Redis for any other reason, go with Redis
If you are hosting at AWS, go wi... | RabbitMQ | 43,264,838 | 77 |
We're trying to set up a basic directed queue system where a producer will generate several tasks and one or more consumers will grab a task at a time, process it, and acknowledge the message.
The problem is, the processing can take 10-20 minutes, and we're not responding to messages at that time, causing the server to... | For now, your best bet is to turn off heartbeats, this will keep RabbitMQ from closing the connection if you're blocking for too long. I am experimenting with pika's core connection management and IO loop running in a background thread but it's not stable enough to release.
In pika v1.1.0 this is ConnectionParameters(h... | RabbitMQ | 14,572,020 | 77 |
I am very new to RabbitMQ.
I have set up a 'topic' exchange. The consumers may be started after the publisher. I'd like the consumers to be able to receive messages that have been sent before they were up, and that was not consumed yet.
The exchange is set up with the following parameters:
exchange_type => 'topic'
dura... | You need a durable queue to store messages if there are no connected consumers available to process the messages at the time they are published.
An exchange doesn't store messages, but a queue can. The confusing part is that exchanges can be marked as "durable" but all that really means is that the exchange itself will... | RabbitMQ | 6,148,381 | 74 |
as opposed to writing your own library.
We're working on a project here that will be a self-dividing server pool, if one section grows too heavy, the manager would divide it and put it on another machine as a separate process. It would also alert all connected clients this affects to connect to the new server.
I am cur... |
what makes them better than writing your own library?
When rolling out the first version of your app, probably nothing: your needs are well defined and you will develop a messaging system that will fit your needs: small feature list, small source code etc.
Those tools are very useful after the first release, when you... | RabbitMQ | 1,823,705 | 74 |
What's the maximum number of queues that RabbitMQ can handle on a single server?
Does it depend on RAM? Does it depends on erlang processes?
| There are not any hard-coded limits inside RabbitMQ broker. The broker will utilize all available resources (unless you set limits on some of them, they are called watermarks in RabbitMQ terminology).
There are some limitations put by Erlang itself, like maximum number of concurrent processes, but if you theoretically ... | RabbitMQ | 22,989,833 | 73 |
On a Windows 7 Enterprise machine, I made a fresh install of Erlang 17.4 and RabbitMQ 3.4.3 x64. The installation was successful and uneventful.
I have not yet tried to create my first queue or exchange, but I already see trouble. This problem is similar to another SO post, but that other post appears to involve cl... | I had this same problem today. There were no cookie or firewall problems and windows reported that the service was running successfully. This is what finally fixed it:
Run RabbitMQ sbin command prompt as administrator.
Run "rabbitmq-service remove"
Run "rabbitmq-service install"
For some reason the service set up b... | RabbitMQ | 28,258,392 | 71 |
Can I get the comparison between RabbitMQ and MSMQ. It will be helpful performance information on different factors are available.
| I wrote a blog post a while back comparing MSMQ and RabbitMQ (among others):
http://mikehadlow.blogspot.co.uk/2011/04/message-queue-shootout.html
RabbitMQ gave slightly better performance than MSMQ, but both were comprehensively out performed by ZeroMQ. If performance is your main criteria, you should definitely look a... | RabbitMQ | 17,806,977 | 70 |
Brief:
Is there a way to install rabbitmq-plugins via a ubuntu package?
Details:
I have rabbitmq running ok in my ubuntu system, and now I'm trying to monitor what's going on via the management plugin. I'm following rabbitmq.com/management.html instructions, but can't execute
rabbitmq-plugins enable rabbitmq_management... | If you are using Ubuntu 12.04
Steps are:--
My rabbitmq server version
# dpkg -l rabbitmq-server
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version ... | RabbitMQ | 8,548,983 | 66 |
The "RabbitMQ in Action" book on page 19 gives these descriptions of exclusive and auto-delete:
exclusive - When set to true, your queue becomes private and can only
be consumed by your app. This is useful when you need to limit a queue
to only one consumer.
auto-delete - The queue is automatically deleted when th... | Well, it is true that exclusive queues will auto-delete when the consumer disconnects (see the documentation pasted below). However, there are cases when you want queues to be non-exclusive, yet still auto-delete (for example, if I want to add another consumer).
exclusive
Exclusive queues may only be accessed by the c... | RabbitMQ | 21,248,563 | 65 |
A little background.
Very big monolithic Django application. All components use the same database. We need to separate services so we can independently upgrade some parts of the system without affecting the rest.
We use RabbitMQ as a broker to Celery.
Right now we have two options:
HTTP Services using a REST interfac... | At first,
REST, RPC - architecture patterns, AMQP - wire-level and HTTP - application protocol which run on top of TCP/IP
AMQP is a specific protocol when HTTP - general-purpose protocol, thus, HTTP has damn high overhead comparing to AMQP
AMQP nature is asynchronous where HTTP nature is synchronous
both REST and RPC ... | RabbitMQ | 16,838,416 | 65 |
Rabbitmq server does not start, saying it's already running:
$: rabbitmq-server
Activating RabbitMQ plugins ...
0 plugins activated:
node with name "rabbit" already running on "android-d1af002161676bee"
diagnostics:
- nodes and their ports on android-d1af002161676bee: [{rabbit,52176},
... | The rabbitmq server was running somewhere but it just couldn't be connected to.
One of the following will mention something about rabbits:
$: ps aux | grep epmd
$: ps aux | grep erl
Kill the process with kill -9 {pid of rabbitmq process}
| RabbitMQ | 8,737,754 | 65 |
I am using rabbitmq:3-management from https://hub.docker.com/_/rabbitmq/ however, it is missing a plugin that I need rabbitmq_delayed_message_exchange.
How can I enable this plugin if it is not available in the image?
| FROM rabbitmq:3.7-management
RUN apt-get update && \
apt-get install -y curl unzip
RUN curl https://dl.bintray.com/rabbitmq/community-plugins/3.7.x/rabbitmq_delayed_message_exchange/rabbitmq_delayed_message_exchange-20171201-3.7.x.zip > rabbitmq_delayed_message_exchange-20171201-3.7.x.zip && \
unzip rabbitmq_delayed_... | RabbitMQ | 52,819,237 | 64 |
I installed RabbitMQ server on OS X, and started it on command line. Now, it is not obvious that how I should stop it from running? After I did:
sudo rabbitmq-server -detached
I get:
Activating RabbitMQ plugins ...
0 plugins activated:
That was it. How should I properly shut it down? In the document, it mentions usin... | It turns out that it is related to permissions. Somehow my rabbitmq server was started with user 'rabbitmq' (which is strange), so that I had to do
sudo -u rabbitmq rabbitmqctl stop
| RabbitMQ | 10,608,950 | 64 |
I'm a newbie with Rabbitmq(and programming) so sorry in advance if this is obvious. I am creating a pool to share between threads that are working on a queue but I'm not sure if I should use connections or channels in the pool.
I know I need channels to do the actual work but is there a performance benefit of having... | I have found this on the rabbitmq website it is near the bottom so I have quoted the relevant part below.
The tl;dr version is that you should have 1 connection per application and 1 channel per thread.
Connections
AMQP connections are typically long-lived. AMQP is an application
level protocol that uses TCP for relia... | RabbitMQ | 10,407,760 | 64 |
I am using RabbitMQ server.
For publishing messages, I set the immediate field to true and tried sending 50,000 messages. Using rabbitmqctl list_queues, I saw that the number of messages in the queue was zero.
Then, I changed the immediate flag to false and again tried sending 50,000 messages. Using rabbitmqctl list_qu... | The immediate and mandatory fields are part of the AMQP specification, and are also covered in the RabbitMQ FAQ to clarify how its implementers interpreted their meaning:
Mandatory
This flag tells the server how to
react if a message cannot be routed to
a queue. Specifically, if mandatory is
set and after runnin... | RabbitMQ | 6,386,117 | 64 |
Given ReadOnlyMemory Struct I want to convert the stream into a string
I have the following code:
var body = ea.Body; //ea.Body is of Type ReadOnlyMemory<byte>
var message = Encoding.UTF8.GetString(body);
Console.WriteLine(" [x] Received {0}", message);
And it gives the following error. I am using the latest C# with .... | You cannot drop a thing that's read-only into a slot typed as byte[], because byte[]s are writable and that would defeat the purpose. It looks like RabbitMQ changed their API in February and perhaps forgot to update the sample code.
A quick workaround is to use .ToArray():
var body = ea.Body.ToArray();
var message = En... | RabbitMQ | 61,374,796 | 62 |
If my understanding is correct, you can't actually look at messages in the rabbit queue without taking them out and putting them back in. There's no way to use rabbitmqctl to inspect a queue.
In some debugging contexts, knowing what is currently in the queue is very useful. Is there a way to get at the messages? Also, ... | There is a "Get Messages" section for each queue in the management API. However this causes the message to be consumed and hence is a destructive action. We can re-queue this message to the queue only at the expense of sacrificing the ordering of messages [for rabbitmq versions < 2.7.0].
A more viable alternative would... | RabbitMQ | 9,874,234 | 62 |
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