Redis BigKey

 文章系转载，便于整理和分类，原文地址：https://zhuanlan.zhihu.com/p/259719757

127.0.0.1:6379> hlen big:hash(integer) 
2000000127.0.0.1:6379> hgetall big:hash
1) "a"
2) "1"

-------- summary -------
Biggest string found 'user:1' has 5 bytes
Biggest list found 'taskflow:175448' has 97478 items
Biggest set found 'redisServerSelect:set:11597' has 49 members
Biggest hash found 'loginUser:t:20180905' has 863 fields
Biggest zset found 'hotkey:scan:instance:zset' has 3431 members
40 strings with 200 bytes (00.00% of keys, avg size 5.00)
2747619 lists with 14680289 items (99.86% of keys, avg size 5.34)
2855 sets with 10305 members (00.10% of keys, avg size 3.61)
13 hashs with 2433 fields (00.00% of keys, avg size 187.15)
830 zsets with 14098 members (00.03% of keys, avg size 16.99)

127.0.0.1:6379> hlen big:hash
(integer) 5000000
127.0.0.1:6379> debug object big:hash
Value at:0x7fda95b0cb20 refcount:1 encoding:hashtable serializedlength:87777785 lru:9625559 lru_seconds_idle:2
(1.08s)

127.0.0.1:6379> strlen key
(integer) 947394

127.0.0.1:6379> memory usage big:hash
(integer) 318663444

127.0.0.1:6379> dbsize
(integer) 1
127.0.0.1:6379> hlen big:hash
(integer) 5000000
#约300MB
127.0.0.1:6379> memory usage big:hash
(integer) 318663444
#约85MB
127.0.0.1:6379> debug object big:hash
Value at:0x7fda95b0cb20 refcount:1 encoding:hashtable serializedlength:87777785 lru:9625814 lru_seconds_idle:9
(1.06s)
127.0.0.1:6379> info memory
# Memory
used_memory_human:402.16M

protected Object readProtocolWithCheckingBroken() {
	Object o = null;
	try {
		o = Protocol.read(inputStream);		return o;
	}catch(JedisConnectionException exc) {
		UsefulDataCollector.collectException(exc, getHostPort(), System.currentTimeMillis());		broken = true;
		throw exc;
	}finally {
		if(o != null) {
			if(o instanceof byte[]) {
				byte[] bytes = (byte[]) o;
				if (bytes.length > threshold) {
					// 做很多事情，例如用ELK完成收集和展示
				}
			}
		}
	}
}

redis-cli client list
id=3 addr=127.0.0.1:58500 fd=8 name= age=3978 idle=25 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=26263554 events=r cmd=hgetall

del bigkey

public void delBigHash(String bigKey) {
	Jedis jedis = new Jedis("127.0.0.1", 6379);
	// 游标
	String cursor = "0";
	while(true) {
		ScanResult<Map.Entry<String, String>> scanResult = jedis.hscan(bigKey, cursor, new ScanParams().count(100));
		// 每次扫描后获取新的游标
		cursor = scanResult.getStringCursor();		// 获取扫描结果
		List<Entry<String, String>> list = scanResult.getResult();		if(list == null || list.size() == 0) {
			continue;		}		String[] fields = getFieldsFrom(list);		// 删除多个field
		jedis.hdel(bigKey, fields);		// 游标为0时停止
		if(cursor.equals("0")) {
			break;
		}	}	// 最终删除key
	jedis.del(bigKey);
}
/**
 * 获取field数组 */
private String[] getFieldsFrom(List<Entry<String, String>> list) {
	List<String> fields = new ArrayList<String>();
	for (Entry<String, String> entry : list) {
		fields.add(entry.getKey());
	}
	return fields.toArray(new String[fields.size()]);
}

public void delBigList(String bigKey) {
	Jedis jedis = new Jedis("127.0.0.1", 6379);
	long llen = jedis.llen(bigKey);
	int counter = 0;
	int left = 100;
	while(counter < llen) {
		// 每次从左侧截掉100个
		jedis.ltrim(bigKey, left, llen);
		counter += left;
	}
	// 最终删除key
	jedis.del(bigKey);
}

public void delBigSet(String bigKey) {
	Jedis jedis = new Jedis("127.0.0.1", 6379);
	// 游标
	String cursor = "0";
	while(true) {
		ScanResult<String> scanResult = jedis.sscan(bigKey, cursor, new ScanParams().count(100));
		// 每次扫描后获取新的游标
		cursor = scanResult.getStringCursor();		// 获取扫描结果
		List<String> list = scanResult.getResult();		if(list == null || list.size() == 0) {
			continue;
		}				jedis.srem(bigKey, list.toArray(new String[list.size()]));
		// 游标为0时停止
		if(cursor.equals("0")) {
			break;
		}	}	// 最终删除key
	jedis.del(bigKey);}

public void delBigSortedSet(String bigKey) {
	long startTime = System.currentTimeMillis();	Jedis jedis = new Jedis(HOST, PORT);	// 游标
	String cursor = "0";
	while(true) {
		ScanResult<Tuple> scanResult = jedis.zscan(bigKey, cursor, new ScanParams().count(100));
		// 每次扫描后获取新的游标
		cursor = scanResult.getStringCursor();		// 获取扫描结果
		List<Tuple> list = scanResult.getResult();		if(list == null || list.size() == 0) {
			continue;		}		String[] members = getMembers(list);		jedis.zrem(bigKey, members);		// 游标为0时停止
		if(cursor.equals("0")) {
			break;
		}	}	// 最终删除key
	jedis.del(bigKey);
}
public void delBigSortedSet2(String bigKey) {
	Jedis jedis = new Jedis(HOST, PORT);
	long zcard = jedis.zcard(bigKey);
	int counter = 0;
	int incr = 100;
	while(counter < zcard) {
		jedis.zremrangeByRank(bigKey, 0, 100);
		// 每次从左侧截掉100个
		counter += incr;
	}
	// 最终删除key
	jedis.del(bigKey);
}