目前业务组新参与了一个项目，涉及到用户积分的增删改查核销等等，预计上线后qps大概在20k左右，我们使用了基于redis的分布式锁来保证数据的一致性。
java
@Slf4j
@Service
public class RedisLockService {
/**
* 加锁lua脚本
*/
private static final String REDIS_LOCK_LUA_SCRIPT = "if redis.call('setnx',KEYS[1],ARGV[1]) == 1 then return redis.call('expire',KEYS[1],ARGV[2]) else return 0 end";
/**
* 解锁lua脚本
*/
private static final String REDIS_UN_LOCK_LUA_SCRIPT = "if redis.call('get', KEYS[1]) == ARGV[1] then return redis.call('del', KEYS[1]) else return 0 end";
/**
* 数据库操作key
*/
private static final String DB_OPERATION_KEY_PREFIX = "operation_key_";
@Resource
private RedisClient redisClient;
/**
* 添加DB数据库锁
*
* @param userId 用户名
* @return 加锁成功之后，返回sequenceId
*/
public String dbLock(int userId) {
String sequenceId = String.valueOf(System.nanoTime());
if (lock(DB_OPERATION_KEY_PREFIX + userId, sequenceId, 10, TimeUnit.SECONDS)) {
return sequenceId;
} else {
recordOne("redis_lock_service_db_lock_fail");
return null;
}
}
/**
* 解数据库锁
*
* @param userId 用户名
* @param sequenceId 序列号
* @return 返回是否解锁成功
*/
public boolean dbUnlock(int userId, String sequenceId) {
boolean result = unLock(DB_OPERATION_KEY_PREFIX + userId, sequenceId);
if (!result) {
recordOne("redis_lock_service_db_un_lock_fail");
}
return result;
}
/**
* 添加分布式锁
*
* @param key 锁的key
* @param sequenceId 唯一Id
* @param expireTime 过期时间
* @param unit 过期时间单位
* @return 返回是否加锁成功
*/
public boolean lock(String key, String sequenceId, int expireTime, TimeUnit unit) {
long start = System.currentTimeMillis();
try {
if (tryLock(key, sequenceId, expireTime, unit, 0)) {
return true;
} else {
log.error("添加分布式锁失败：key={}", key);
recordOne("redis_lock_service_lock_fail");
return false;
}
} catch (Exception e) {
log.error("添加分布式锁异常：key={}", key, e);
recordOne("redis_lock_service_lock_exception");
} finally {
recordQuantile("redis_lock_service_lock", System.currentTimeMillis() - start);
}
return false;
}
public boolean lock(String key, String sequenceId, int expireTime, TimeUnit unit, int waitTimeInMills) {
long start = System.currentTimeMillis();
try {
if (tryLock(key, sequenceId, expireTime, unit, waitTimeInMills)) {
return true;
} else {
log.error("添加分布式锁失败：key={}", key);
recordOne("redis_lock_service_lock_fail");
return false;
}
} catch (Exception e) {
log.error("添加分布式锁异常：key={}", key, e);
recordOne("redis_lock_service_lock_exception");
} finally {
recordQuantile("redis_lock_service_lock", System.currentTimeMillis() - start);
}
return false;
}
public String lockWithWaitTime(String key, int expireTime, int waitTimeInMills) {
long start = System.currentTimeMillis();
String sequenceId = String.valueOf(System.nanoTime());
if (tryLock(DB_OPERATION_KEY_PREFIX + key, sequenceId, expireTime, TimeUnit.SECONDS, waitTimeInMills)) {
recordQuantile("redis_lockNew_service_lock", System.currentTimeMillis() - start);
return sequenceId;
} else {
log.error("lockNew 添加分布式锁失败：key={}", key);
recordOne("redis_lockNew_service_lock_fail");
return null;
}
}
/**
* 解分布式锁
*
* @param key 解锁key
* @param sequenceId 唯一的一个Id
* @return 返回解锁是否成功
*/
public boolean unLock(String key, String sequenceId) {
long start = System.currentTimeMillis();
try {
long result = redisClient.getSession(key, true).getSingleConnectionExecutor().evalAutoSha(REDIS_UN_LOCK_LUA_SCRIPT, ResultType.INTEGER, new String[]{key}, new String[]{sequenceId}).get(500, TimeUnit.MILLISECONDS);
if (result > 0) {
return true;
} else {
log.error("解锁失败：key={}", key);
recordOne("redis_lock_service_un_lock_fail");
return false;
}
} catch (Exception e) {
recordOne("redis_lock_service_un_lock_exception");
log.error("解锁异常：key={}", key, e);
} finally {
recordQuantile("redis_lock_service_un_lock", System.currentTimeMillis() - start);
}
return false;
}
/**
* Redis 尝试加锁
*
* @param key 加锁的Key
* @param expireTime 过期时间
* @param timeUnit 时间单位
* @param waitTimeInMills 等待时间
* @return 返回加锁是否成功
*/
private boolean tryLock(final String key, String sequenceId, int expireTime, TimeUnit timeUnit, int waitTimeInMills) {
log.info("redis_lock_service_tryLock_add, userId={}, sequenceId={}", key, sequenceId);
long start = System.currentTimeMillis();
long expireTimeSecond = timeUnit.toSeconds(expireTime);
try {
while (redisClient.getSession(key, true).getSingleConnectionExecutor().evalAutoSha(REDIS_LOCK_LUA_SCRIPT, ResultType.INTEGER, new String[]{key}, new String[]{sequenceId, String.valueOf(expireTimeSecond)}).get(500, TimeUnit.MILLISECONDS) <= 0) {
long time = System.currentTimeMillis() - start;
if (time > waitTimeInMills) {
log.error("尝试添加分布式锁失败：key={} time:{}， 超时返回", key, time);
log.info("redis_lock_service_tryLock_timeout_fail, userId={}, sequenceId={}", key, sequenceId);
recordOne("redis_lock_service_tryLock_timeout_fail");
return false;
}
log.info("尝试添加分布式锁成功：key={} time:{}， 等待中", key, time);
TimeUnit.MILLISECONDS.sleep(10);
}
return true;
} catch (Exception e) {
Long unlockResult = null;
try {
unlockResult = redisClient.getSession(key, true).getSingleConnectionExecutor().evalAutoSha(REDIS_UN_LOCK_LUA_SCRIPT, ResultType.INTEGER, new String[]{key}, new String[]{sequenceId}).get(500, TimeUnit.MILLISECONDS);
} catch (Exception exception) {
log.error("尝试添加分布式锁失败后解锁异常：key={}", key, e);
recordOne("redis_lock_service_try_lock_unlock_exception");
}
log.error("尝试添加分布式锁失败：key={}， 解锁结果：{}", key, unlockResult, e);
recordOne("redis_lock_service_try_lock_exception");
} finally {
recordQuantile("redis_lock_service_try_lock", System.currentTimeMillis() - start);
}
log.info("redis_lock_service_tryLock_fail, userId={}, sequenceId={}", key, sequenceId);
return false;
}
}