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Tair (Redis® OSS-Compatible):Client-side throttling

Last Updated:Apr 11, 2026

After you enable the QPS throttling feature, you may receive THROTTLED errors if requests to an instance exceed the specified threshold. This topic provides code examples for implementing a retry strategy to handle these errors.

Jedis

This example uses Jedis version 5.2.0.

Retry parameters

Parameter Value Description
MAX_RETRY 10 Maximum retry attempts before throwing the exception
Initial backoff 2 s Wait time before the first retry (2¹ seconds)
Backoff multiplier 2x Each subsequent retry doubles the wait: 2 s, 4 s, 8 s, ...
Retried error THROTTLED Only THROTTLED errors are retried; all other errors propagate immediately

Maven dependency

<!-- This example uses version 5.2.0. -->
<dependency>
    <groupId>redis.clients</groupId>
    <artifactId>jedis</artifactId>
    <version>5.2.0</version>
</dependency>

Code sample

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;
import redis.clients.jedis.JedisPoolConfig;
import redis.clients.jedis.exceptions.JedisException;

public class JedisThrottledTest {
    private static final Logger logger = LoggerFactory.getLogger(JedisThrottledTest.class);

    private static final int MAX_RETRY = 10; // Maximum retry attempts

    public static void main(String[] args) {
        if (args.length < 3) {
            System.out.println("Usage: java -jar JedisThrottledTest.jar <host> <port> <password>");
            return;
        }

        String host = args[0];
        int port = Integer.parseInt(args[1]);
        String password = args[2];

        JedisPoolConfig poolConfig = new JedisPoolConfig();
        poolConfig.setMaxTotal(32);
        poolConfig.setMaxIdle(32);
        poolConfig.setMinIdle(16);

        JedisPool jedisPool = new JedisPool(poolConfig, host, port, 3000, password);
        for (int i = 0; i < 4; i++) {
            new Thread(new Runnable() {
                @Override
                public void run() {
                    for (int i = 0; i < Integer.MAX_VALUE; i++) {
                        executeWithRetry(jedisPool, "key" + i, "value" + i);
                    }
                }
            }).start();
        }
    }

    private static void executeWithRetry(JedisPool jedisPool, String key, String value) {
        int retryCount = 0;
        while (retryCount < MAX_RETRY) {
            try (Jedis jedis = jedisPool.getResource()) {
                jedis.set(key, value);
                break;
            } catch (JedisException e) {
                if (e.getMessage().contains("THROTTLED")) {
                    logger.info("Throttled error occurred (attempt " + retryCount + "): " + e.getMessage());
                    retryCount++;
                    if (retryCount >= MAX_RETRY) {
                        logger.info("Max retry attempts reached.");
                        throw e;
                    }
                    try {
                        int sleepTime = (int)Math.pow(2, retryCount);
                        Thread.sleep(sleepTime * 1000);
                    } catch (InterruptedException ie) {
                        Thread.currentThread().interrupt();
                        throw new RuntimeException("Thread interrupted during retry delay", ie);
                    }
                } else {
                    throw e;
                }
            }
        }
    }
}

Valkey-java

Important

Use valkey-java version 5.4.0 or later.

Retry parameters

Parameter Value Description
maxAttempts 100 Maximum retry attempts
maxTotalRetriesDuration 1,000 s Maximum total time spent on retries
Initial backoff 1 s Wait time before the first retry (2⁰ seconds)
Backoff multiplier 2x Each subsequent retry doubles the wait: 1 s, 2 s, 4 s, ...
Retried error THROTTLED Only messages containing THROTTLED trigger the backoff callback

Maven dependency

<dependency>
    <groupId>io.valkey</groupId>
    <artifactId>valkey-java</artifactId>
    <version>5.4.0</version>
</dependency>

Code sample

The ExceptionHandler in Valkey-java lets you register callbacks for specific error patterns. This example registers an exponential backoff callback for THROTTLED errors, so the retry logic is separate from your application code.

import java.time.Duration;

import io.valkey.DefaultJedisClientConfig;
import io.valkey.ExceptionHandler;
import io.valkey.HostAndPort;
import io.valkey.UnifiedJedis;
import io.valkey.providers.PooledConnectionProvider;
import org.apache.commons.pool2.impl.GenericObjectPoolConfig;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class ThrottledTest {
    private static final Logger logger = LoggerFactory.getLogger(ThrottledTest.class);

    /**
     * Implements exponential backoff.
     */
    static class ExponentialBackoffCallback implements ExceptionHandler.ErrorCallback {
        private int attempt = 0;

        @Override
        public void onError(String errorMessage) {
            int sleepTime = (int)Math.pow(2, attempt);
            try {
                logger.info("Sleeping for " + sleepTime + " seconds before handling: " + errorMessage);
                Thread.sleep(sleepTime * 1000);
            } catch (InterruptedException ie) {
                // Ignore the error.
            }
            attempt++;
        }
    }

    public static void main(String[] args) {
        if (args.length < 3) {
            System.out.println("Usage: java -jar ThrottledTest.jar <host> <port> <password>");
            return;
        }

        String host = args[0];
        int port = Integer.parseInt(args[1]);
        String password = args[2];

        GenericObjectPoolConfig poolConfig = new GenericObjectPoolConfig();
        poolConfig.setMaxTotal(32);
        poolConfig.setMaxIdle(32);
        poolConfig.setMinIdle(16);

        int maxAttempts = 100; // Maximum retry attempts
        Duration maxTotalRetriesDuration = Duration.ofSeconds(1000); // Maximum total duration for retries
        PooledConnectionProvider provider = new PooledConnectionProvider(new HostAndPort(host, port),
            DefaultJedisClientConfig.builder().password(password).build(), poolConfig);

        ExceptionHandler handler = new ExceptionHandler();
        handler.register(
            message -> message.contains("THROTTLED"),
            new ExponentialBackoffCallback()
        );

        UnifiedJedis unifiedJedis = new UnifiedJedis(provider, maxAttempts, maxTotalRetriesDuration, handler);
        for (int i = 0; i < 4; i++) { // Use four threads to generate high QPS.
            new Thread(new Runnable() {
                @Override
                public void run() {
                    for (int i = 0; i < Integer.MAX_VALUE; i++) {
                        try {
                            unifiedJedis.set("" + i, "" + i);
                        } catch (Exception e) {
                            logger.error("Error occurred {}", e.getMessage());
                        }
                    }
                }
            }).start();
        }
    }
}

redis-py

This example uses redis-py version 6.1.1.

Retry parameters

Parameter Value Description
MAX_RETRY 10 Maximum retry attempts before raising the exception
Initial backoff 2 s Wait time before the first retry (2¹ seconds)
Backoff multiplier 2x Each subsequent retry doubles the wait: 2 s, 4 s, 8 s, ...
socket_timeout 3 s Connection timeout
Retried error THROTTLED Only THROTTLED errors are retried; all other RedisError exceptions propagate immediately

Code sample

import sys
import time
import threading
import logging
from redis import Redis, RedisError

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

MAX_RETRY = 10  # Maximum retry attempts

def execute_with_retry(redis_client, key, value):
    retry_count = 0
    while retry_count < MAX_RETRY:
        try:
            redis_client.set(key, value)
            break  # If successful, exit the loop.
        except RedisError as e:
            if "THROTTLED" in str(e):
                logger.info(f"Throttled error occurred (attempt {retry_count}): {e}")
                retry_count += 1
                if retry_count >= MAX_RETRY:
                    logger.info("Max retry attempts reached.")
                    raise e
                sleep_time = 2 ** retry_count
                time.sleep(sleep_time)
            else:
                logger.error(f"Non-throttled Redis error: {e}")
                raise e

def worker(redis_client):
    i = 0
    while True:
        try:
            execute_with_retry(redis_client, f"key{i}", f"value{i}")
            i += 1
        except Exception as e:
            logger.exception(f"Unexpected error in worker: {e}")
            time.sleep(1)  # Avoid tight loop in case of persistent errors

def main():
    if len(sys.argv) < 4:
        print("Usage: python script.py <host> <port> <password>")
        return

    host = sys.argv[1]
    port = int(sys.argv[2])
    password = sys.argv[3]

    redis_client = Redis(
        host=host,
        port=port,
        password=password,
        socket_timeout=3,
        decode_responses=True
    )

    # Test the connection.
    try:
        redis_client.ping()
        logger.info("Successfully connected to Redis")
    except RedisError as e:
        logger.error(f"Failed to connect to Redis: {e}")
        return

    # Create and start 10 threads.
    threads = []
    for i in range(10):
        thread = threading.Thread(target=worker, args=(redis_client,))
        thread.daemon = True
        thread.start()
        threads.append(thread)
        logger.info(f"Started worker thread {i}")

    # Keep the main thread running.
    try:
        while True:
            time.sleep(1)
    except KeyboardInterrupt:
        logger.info("Program interrupted. Exiting...")

    # Wait for all threads to complete.
    for thread in threads:
        thread.join()

if __name__ == "__main__":
    main()