AWS Elasticache: Lettuce client: Retry mechanism

[alekhya538]

Hello there!
I am using Lettuce (https://github.com/redis/lettuce) java client to read/write to AWS Elasticache.
Below is my method to read from Cache by passing key.

    public Object getJson(String key) {
        log.info("Reading from cache for key: {}", key);
        RedisAsyncCommands<String, String> async = null;
        try {
            async = redisCacheClient.connect().async();
            return async.jsonGet(key, JsonPath.ROOT_PATH).get();
        } catch (Exception e) {
            log.error("Exception while reading from Cache" + e.getLocalizedMessage());
            return null;
        } finally {
            Objects.requireNonNull(async).quit();
        }
    }

However, I want to implement a RETRY mechanism where if the first call to read from cache fails, I want to try one more time. Is there any Lettuce config available to achieve this ?

Thanks,
Alex

[tishun]

Hey Alex,

To give you a good explanation I must better understand what "fails" means in your case.
Do you mean some sort of connection error?

Lettuce has a built-in retry mechanism as part of it's command execution reliability:

Switching between at-least-once and at-most-once operations¶
Lettuce’s consistency levels are bound to retries on reconnects and the connection state. By default, Lettuce operates in the at-least-once mode. Auto-reconnect is enabled and as soon as the connection is re-established, queued commands are re-sent for execution. While a connection failure persists, issued commands are buffered.

To change into at-most-once consistency level, disable auto-reconnect mode. Connections cannot be longer reconnected and thus no retries are issued. Not successfully commands are canceled. New commands are rejected.

Does that help?