记一次因 Redis 使用不当导致应用卡死 bug 的排查及解决！
往期热门文章：
首先说下问题现象：内网sandbox环境API持续1周出现应用卡死，所有api无响应现象
top -H -p 12798
jstack 12798 |grep 12799的16进制 31ff
/**
* Returns a Jedis instance to be used as a Redis connection. The instance can be newly created or retrieved from a
* pool.
*
* @return Jedis instance ready for wrapping into a {@link RedisConnection}.
*/
protected Jedis fetchJedisConnector() {
try {
if (usePool && pool != null) {
return pool.getResource();
}
Jedis jedis = new Jedis(getShardInfo());
// force initialization (see Jedis issue #82)
jedis.connect();
return jedis;
} catch (Exception ex) {
throw new RedisConnectionFailureException("Cannot get Jedis connection", ex);
}
}
public T getResource() {
try {
return internalPool.borrowObject();
} catch (Exception e) {
throw new JedisConnectionException("Could not get a resource from the pool", e);
}
}
public T borrowObject(long borrowMaxWaitMillis) throws Exception {
this.assertOpen();
AbandonedConfig ac = this.abandonedConfig;
if (ac != null && ac.getRemoveAbandonedOnBorrow() && this.getNumIdle() < 2 && this.getNumActive() > this.getMaxTotal() - 3) {
this.removeAbandoned(ac);
}
PooledObjectp = null;
boolean blockWhenExhausted = this.getBlockWhenExhausted();
long waitTime = 0L;
while(p == null) {
boolean create = false;
if (blockWhenExhausted) {
p = (PooledObject)this.idleObjects.pollFirst();
if (p == null) {
create = true;
p = this.create();
}
if (p == null) {
if (borrowMaxWaitMillis < 0L) {
p = (PooledObject)this.idleObjects.takeFirst();
} else {
waitTime = System.currentTimeMillis();
p = (PooledObject)this.idleObjects.pollFirst(borrowMaxWaitMillis, TimeUnit.MILLISECONDS);
waitTime = System.currentTimeMillis() - waitTime;
}
}
if (p == null) {
throw new NoSuchElementException("Timeout waiting for idle object");
}
if (p == null) {
if (borrowMaxWaitMillis < 0L) {
p = (PooledObject)this.idleObjects.takeFirst();
} else {
waitTime = System.currentTimeMillis();
p = (PooledObject)this.idleObjects.pollFirst(borrowMaxWaitMillis, TimeUnit.MILLISECONDS);
waitTime = System.currentTimeMillis() - waitTime;
}
}
public E takeFirst() throws InterruptedException {
this.lock.lock();
Object var2;
try {
Object x;
while((x = this.unlinkFirst()) == null) {
this.notEmpty.await();
}
var2 = x;
} finally {
this.lock.unlock();
}
return var2;
}
JedisConnectionFactory jedisConnectionFactory = new JedisConnectionFactory();
.......
JedisPoolConfig config = new JedisPoolConfig();
config.setMaxWaitMillis(2000);
.......
jedisConnectionFactory.afterPropertiesSet();
org.springframework.data.redis.RedisConnectionFailureException: Cannot get Jedis connection; nested exception is redis.clients.jedis.exceptions.JedisConnectionException: Could not get a resource fr
om the pool
at org.springframework.data.redis.connection.jedis.JedisConnectionFactory.fetchJedisConnector(JedisConnectionFactory.java:140)
at org.springframework.data.redis.connection.jedis.JedisConnectionFactory.getConnection(JedisConnectionFactory.java:229)
at org.springframework.data.redis.connection.jedis.JedisConnectionFactory.getConnection(JedisConnectionFactory.java:57)
at org.springframework.data.redis.core.RedisConnectionUtils.doGetConnection(RedisConnectionUtils.java:128)
at org.springframework.data.redis.core.RedisConnectionUtils.getConnection(RedisConnectionUtils.java:91)
at org.springframework.data.redis.core.RedisConnectionUtils.getConnection(RedisConnectionUtils.java:78)
at org.springframework.data.redis.core.RedisTemplate.execute(RedisTemplate.java:177)
at org.springframework.data.redis.core.RedisTemplate.execute(RedisTemplate.java:152)
at org.springframework.data.redis.core.AbstractOperations.execute(AbstractOperations.java:85)
at org.springframework.data.redis.core.DefaultHashOperations.get(DefaultHashOperations.java:48)
.......
Cursor c = stringRedisTemplate.getConnectionFactory().getConnection().scan(options);
while (c.hasNext()) {
.....,,
}
stringRedisTemplate.getConnectionFactory().getConnection()
stringRedisTemplate.execute(new RedisCallback () {
@Override
public Cursor doInRedis(RedisConnection connection) throws DataAccessException {
return connection.scan(options);
}
});
RedisConnectionUtils.releaseConnection(conn, factory);
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