I have a cassandra cluster with 4 nodes. Data is stored with a replication factor of 3. One morning, couple of my tables had no data in it. It used to have around 500 entries and all of a sudden it vanished. 

I have checked all possible ways in which data could be lost. 

1. I checked application logs but no delete operation was fired from the application.
2. I checked SSH logs but no unauthorised access has bgeen made to the DB servers.

I cant find any clue why this could happen. Can anybody suggest me a possible reason?

**Pls find table definition below**

```
CREATE TABLE test.users (
    id text,
    userid text,  
    updatetime timestamp,
    PRIMARY KEY (id, userid)
) WITH CLUSTERING ORDER BY (userid ASC)
    AND bloom_filter_fp_chance = 0.01
    AND caching = {'keys': 'ALL', 'rows_per_partition': 'NONE'}
    AND comment = ''
    AND compaction = {'class': 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy', 'max_threshold': '32', 'min_threshold': '4'}
    AND compression = {'chunk_length_in_kb': '64', 'class': 'org.apache.cassandra.io.compress.LZ4Compressor'}
    AND crc_check_chance = 1.0
    AND dclocal_read_repair_chance = 0.1
    AND default_time_to_live = 0
    AND gc_grace_seconds = 864000
    AND max_index_interval = 2048
    AND memtable_flush_period_in_ms = 0
    AND min_index_interval = 128
    AND read_repair_chance = 0.0
    AND speculative_retry = '99PERCENTILE';

```