How can I get number of connection per clients in Redis Cluster - redis

From Redis CLI I can see number of connected clients by running client list.
Now I want to see number connection per client(by addr or id) made to Redis Cluster.
Is there any way to do so. Thanks in advance.

You can call redis-cli --cluster call <ip>:<port> CLIENT LIST and have a shell script to grep/sort/aggregate the results per client address/id.

Related

Remote workers on multiple servers with python-rq (redis)

I am using redis and python-rq to manage a data processing task. I wish to distribute the data processing across multiple servers (each server would manage several rq workers) but I would like to keep a unique queue on a master server.
Is there a way to achieve this using python-rq ?
Thank you.
It turned out to be easy enough. There are two steps:
1) Configure Redis on the master machine so that it is open to external communications by the remote "agent" server. This is done by editing the bind information as explained in this post. Make sure to set a password if setting the bind value to 0.0.0.0 as this will open the Redis connection to anyone.
2) Start the worker on the remote "agent" server using the url parameter:
rq worker --url redis://:[your_master_redis_password]#[your_master_server_IP_address]
On the master server, you can check that the connection was properly made by typing:
rq info --url redis://:[your_master_redis_password]#localhost
If you enabled the localhost binding, this should display all the workers available to Redis from your "master" including the new worker you created on your remote server.

How to make AWS Elasticache Redis split read requests across all read replicas?

I have a Redis Elasticache non-clustered instance with one primary node and two read replicas. Using the Stack Exchange Redis client I provide the reader endpoint and make a get request. Based on the documentation I would expect:
A reader endpoint will split incoming connections to the endpoint
between all read replicas in a Redis cluster.
However, 100% of the requests go to one of the read replicas. First question, why? Second question, how do I get Redis to distribute the load across all of the read replicas without having to manage the read instances at an application level?
You should use the "Reader Endpoint" connection string. (the connection string with "-ro")
This will split the connection between your replicas in case you have more than one connection to the Redis Cache server. Also to achieve this you need to have significant CPU usage to the first redis-replica server.

How to find list of sources[IP] of the redis messages in Redis server

My Redis Server instance handles with multiple publishers. How can I find the list of sources[IP] which published messages in Redis Server in a particular time limit?
I have got an answer and posting it for other's reference.
redis-cli>client list
This above command will give the list of IPs connected to receive/send messages.

How to get all Connected Clients of Redis Cluster?

How to get all connected clients of a redis cluster?
I am using AWS elasticCache redis with non cluster mode and redission as my redis client.
My Use Case:
I need to run specific code from only 1 connected redis client.
Thanks
redis has command about client information like CLIENT LIST, check out this page .
you could checkout this page for the command redisson has not supported yet.

How to get notifications about failovers in Redis cluster to the client application

Is there a way for a client to get notified about failover events in the Redis cluster? If so, which client library would support this? I am currently using Jedis but have the flexibility to switch to any other Java client.
There are two ways that I can think of to check this, one of them is to grep for master nodes on the cluster, keeping in mind their IDs, if the ports changed for any of them then a failover happened.
$ redis-cli -p {PORT} cluster nodes | grep master
Another way, but it is not as robust of a solution is using the consistency checker ruby script, that will start showing errors in writes as an output, which you can monitor and send notifications depending on it, since that happens when the read server is trying to take its master's role.
Sentinel (http://redis.io/topics/sentinel) has the ability to monitor the cluster member, and send a publish/subscribe notification upon failure. The link contains a more in-depth explanation and tutorial.