I want to set LFU eviction policy for redis.
how to configure eviction policy like LFU and LRU with the help of jcache API or redisson API?
You could not configure eviction policy via APIs; The only way is to edit the maxmemory-policy directive in redis conf file
Related
Disclaimer, I'm new to redis and elasticache.
Referencing an answer in this stackoverflow here.
I have a basic AWS ElastiCache Redis cluster setup:
3 shards, 9 nodes
encryption at rest
However, when I try to connect to the Configuration endpoint I get READONLY You can't write against a read-only replica'.
If I change my connection string to a node endpoint, I connect successfully.
What am I missing here? Why isn't the configuration endpoint navigating me to a non READONLY node?
make sure you are copying the primary end point, replica is only read, Since Redis 2.6, replicas support a read-only mode that is enabled by default. This behavior is controlled by the replica-read-only option in the redis.conf file, and can be enabled and disabled at runtime using CONFIG SET.
I have a Redis database (no cluster, no replica).
How can i configure it to be read only? (so client can not modify it)
I do not want to set up a replication or cluster.
Thanks in advance
There is no such configuration for Redis master. Only replicas can be configured as read-only. If you have control over the Redis client library used by your clients, you can change it to expose only read methods to the clients.
In Apache Ignote, when an entry is evicted from an on-heap cache, is it placed in the off-heap region?
From the docs, it doesn't seem so but looking for a clarification.
The on-heap eviction policies remove the cache entries from Java heap only. The entries stored in the off-heap region of the memory are not affected.
Starting with Ignite 2.x, entries are always stored in off-heap memory and on-heap option allows enabling a lookup on-heap cache for the off-heap entries. When an entry is evicted from on-heap cache there is always a backing off-heap counterpart.
Ignite before 2.x uses different memory modes and eviction behavior differs depending on it.
First I would like to thanks a lot for this forum.
I have a doubt about the cluster configuration with Hazelcast and Load Balance.
In the documentation https://docs.wso2.com/display/CLUSTER420/Clustering+the+Gateway
in section load balance configuration appear:
upstream wso2.am.com {
**sticky cookie JSESSIONID;**
server xxx.xxx.xxx.xx4:9763;
server xxx.xxx.xxx.xx5:9763;
}
Why to use sticky if the cluster already make the session control?
My understanding is wrong?
Thanks a lot.
In APIM, hazelcast clustering is used for cache invalidation among nodes, inter-node communication for dep-sync etc, but not for session replication. Therefore you need sticky sessions.
I am currently setting up an infrastructure for an App in AWS. App is written in Django and is using Redis for some transactions. High availability is key for this application and I am having a hard time trying to get my head around how to configure Redis for High availability.
Application level changes are not an option.
Ideally I would like to have a redis setup, to which I can write and read and replicate and scale when required.
Current Setup is a Redis Fail-over scenario with HAProxy --> Redis Master --> Replica Slave.
Could someone guide me understand various options ? and how to scale redis for high availability !
Use AWS ElastiCache Redis Cluster with Multi-AZ. They provides automatic fail-over. It provides endpoint to access master node.
If master goes down AWS route your endpoint to another node. everything happens automatically, you don't have to do anything.
Just make sure that if you are doing DNS to IP caching in your application, its set to 60 seconds or so instead of default.
http://docs.aws.amazon.com/AmazonElastiCache/latest/UserGuide/AutoFailover.html
Thanks,
KS