Aloha-Client

For more information, about the aloha project, check out Aloha and Aloha-Server.

Configuration

tl;dr: java -Xmx256m -Xms256m -jar aloha-client-*.jar

Memory Settings

The client is pretty lean: After running the gc, memory consumption is ~20MB. -Xmx256m -Xms256m is a generous setting.

Server and Cluster Settings

Cluster Mode

If you only have one server node, you have to set infinispan.cluster.mode to server. In production you should have more than one node, then you have to set this value to cluster.

Initial Server

You need to give the client a seed IP for the startup. Afterwards it will be kept up to date on topology changes and will also take care of fail-overs. If you are on AWS, it's fairly easy to get an IP address from the AWS API. Have a look at the very powerful aws cli!

Here's an example how you could find out your ECS instance based on the cluster name:

aws ec2 describe-instances --filters Name=tag:Name,Values=*aloha-server-sg \
    Name=instance-state-name,Values=running | jq .Reservations[0].Instances[0].PrivateIpAddress

You can define the initial server name with this key: infinispan.cluster.initialServer: 10.221.123.5

Cluster Name

The client needs the cluster name for the initial connect. Infinispan supports cluster-failover, so every cluster needs a unique name.

The name can be set with this key: infinispan.cluster.name: aloha-server-sg

Caching

Caching is disabled by default. If you activate it, you have to make sure that you provide enough heap memory to accommodate all items in the cache. The cache is running in invalidation-mode and you have to provide the maximum number of entries the cache can hold. If this number is exceeded, the cache will evict items with the LRU algorithm.

That's how you configure the cache:

infinispan:
  
  ...
  
  cache:
    enabled: false
    maxEntries: 50000

So the keys would be:

• infinispan.cache.enabled
• infinispan.cache.maxEntries

Example

infinispan.cluster.mode: cluster infinispan.cluster.initialServer: 10.221.123.5 infinispan.cluster.name: aloha-sg infinispan.cache.enabled: false

Load Balancing

If you are running a replication cluster, the infinispan client will balance the load on all available nodes via Round-Robin. In distributed mode, the client will hash the keys to find the owner of the server and only open connections to this specific server to reduce the load.