4.3 Redis Configuration
- Jenni Wallin
- Former user (Deleted)
- Kevin Wu
After Redis has been installed, you can create Redis profiles in 
to communicate with Redis. For information on how to extend the Redis database, see https://aws.amazon.com/documentation/elasticache/.
Note!
Created or updated Redis profiles that are used for PCC do not become effective until you restart the EC/ECSAs.
Redis Profiles
A Redis profile is used to read and write data in a Redis database. This profile can be accessed by workflows using Aggregation, Distributed Storage or PCC.
As a client to Redis, the profile operates in synchronous mode. When sending a request to Redis, the profile expects a server response, indicating success or failure, before proceeding to send the next one in queue.
PCC using a Redis profile has been verified using Amazon ElastiCache.
To create a new , click on the button in the upper left part of the Desktop window, and then select from the menu.
To open an existing , double-click on the configuration in the Configuration Navigator , or right-click on the configuration, and then select Open Configuration(s)....
In a Redis profile, there are two tabs; Connectivity and Advanced.
Connectivity Tab
The Connectivity tab is displayed by default.
The Redis Profile - Connectivity tab
The following settings are available in the Connectivity tab:
| Setting | Description |
|---|---|
Host | Enter the IP address/DNS name of the cluster. |
Port | Enter the listening port of the cluster. |
Password | Enter the password of the cluster. |
| Operation Timeout (ms) | Enter the number of milliseconds after which Redis "CRUD" operations, i e create, read, update, and delete, should timeout. Setting a lower value than the default 1000 ms may have a positive impact on throughput performance. However, if the value is set too low, indicated by a large number of operation timeouts errors in the EC/ECSA logs, a lower throughput can be expected. |
| Retry Interval Time (ms) | Enter the time interval, in milliseconds, that you want to wait before trying to read the cluster configuration again after a failed attempt. The default value is 5. |
| Max Number of Retries | Enter the maximum number of retries. The default value is 30. |
Advanced Configurations
The Advanced tab contains additional properties that you can use for performance tuning.
The Redis profile - Advanced tab
The property mz.redis.socket.timeout specifies how long the Redis client will try to open a socket connection before it times out, while the property mz.redis.connection.timeout determines the maximum amount of time that the Redis client waits to read data from the Redis server before it times out.
Idle connections will timeout after the time specified in mz.redis.connection.time.limit has expired. These connections will be returned to the pool and are considered unused. The profile will periodically remove (evict) unused connections to the Redis cluster. Use mz.redis.connection.time.limit to control the time between the eviction intervals.
Connections in use are periodically and unconditionally reset. Use mz.redis.connection.time.limit to control the time between the reset intervals. In case of topology changes the connections are reset after a delay. Use mz.redis.topology.limit.time to set the length of this delay.
Note!
When using global variables, the normal locking used by Redis (optimistic locking) can cause the code to become unpredictable, due to the built-in multi-threading of APL. One way to solve this is to use pessimistic locking, which prevents aggregation timeout threads from executing concurrently. In this case global variables are thread-safe. When using pessimistic locking the timeout becomes slower so if no global variables are used, optimistic locking may be preferred.
Use the properties mz.redis.agg.lock.method and mz.redis.agg.locktime for pessimistic locking of aggregation timeouts. The lock algorithm is implemented according to https://redis.io/commands/setnx.
If you require to add a server to the Redis cluster, see https://aws.amazon.com/documentation/elasticache/ for further information.