Restore Accidental Dropped Table In Cassandra

Step 1: I created one table by using the below command

CREATE TABLE Cricket (
    PlayerID uuid,
    LastName varchar,
    FirstName varchar,  
    City varchar,
    State varchar,
    PRIMARY KEY (PlayerID));

Step 2: Insert 3 records by using the below command

INSERT INTO Cricket (PlayerID, LastName, FirstName, City, State)
VALUES (now(), 'Pendulkar', 'Sachin', 'Mumbai','Maharastra');
INSERT INTO Cricket (PlayerID, LastName, FirstName, City, State)
VALUES (now(), 'Vholi', 'Virat', 'Delhi','New Delhi');
INSERT INTO Cricket (PlayerID, LastName, FirstName, City, State)
VALUES (now(), 'Sharma', 'Rohit', 'Berhampur','Odisha');

Step 3: Accidentally I deleted the Cricket table

drop table Cricket;

Step-4: Need to recover that table by using auto snapshot backup Note: auto_snapshot (Default: true ) Enable or disable whether a snapshot is taken of the data before keyspace truncation or dropping of tables. To prevent data loss, using the default setting is strongly advised.

Step 5: Find the snapshot locations and files

cassandra@node1:~/data/students_details$ cd cricket-88128dc0960d11ea947b39646348bb4f
cassandra@node1:~/data/students_details/cricket-88128dc0960d11ea947b39646348bb4f$ ls -lrth
total 0
drwxrwxr-x 2 cassandra cassandra  6 May 14 18:05 backups
drwxrwxr-x 3 cassandra cassandra 43 May 14 18:06 snapshots

Step 6: You will get one .cql file in that snapshot location that has tables DDL.

cassandra@node1:~/data/students_details/cricket-88128dc0960d11ea947b39646348bb4f/snapshots/dropped-1589479603749-cricket$ ls -lrth
total 44K
-rw-rw-r-- 1 cassandra cassandra   92 May 14 18:06 md-1-big-Summary.db
-rw-rw-r-- 1 cassandra cassandra   61 May 14 18:06 md-1-big-Index.db
-rw-rw-r-- 1 cassandra cassandra   16 May 14 18:06 md-1-big-Filter.db
-rw-rw-r-- 1 cassandra cassandra  179 May 14 18:06 md-1-big-Data.db
-rw-rw-r-- 1 cassandra cassandra   92 May 14 18:06 md-1-big-TOC.txt
-rw-rw-r-- 1 cassandra cassandra 4.7K May 14 18:06 md-1-big-Statistics.db
-rw-rw-r-- 1 cassandra cassandra    9 May 14 18:06 md-1-big-Digest.crc32
-rw-rw-r-- 1 cassandra cassandra   43 May 14 18:06 md-1-big-CompressionInfo.db
-rw-rw-r-- 1 cassandra cassandra  891 May 14 18:06 schema.cql
-rw-rw-r-- 1 cassandra cassandra   31 May 14 18:06 manifest.json
cassandra@node1:~/data/students_details/cricket-88128dc0960d11ea947b39646348bb4f/snapshots/dropped-1589479603749-cricket$

more schema.cql
cassandra@node1:~/data/students_details/cricket-88128dc0960d11ea947b39646348bb4f/snapshots/dropped-1589479603749-cricket$ more schema.cql
CREATE TABLE IF NOT EXISTS students_details.cricket (
        playerid uuid PRIMARY KEY,
        city text,
        firstname text,
        lastname text,
        state text)
        WITH ID = 88128dc0-960d-11ea-947b-39646348bb4f
        AND bloom_filter_fp_chance = 0.01
        AND dclocal_read_repair_chance = 0.1
        AND crc_check_chance = 1.0
        AND default_time_to_live = 0
        AND gc_grace_seconds = 864000
        AND min_index_interval = 128
        AND max_index_interval = 2048
        AND memtable_flush_period_in_ms = 0
        AND read_repair_chance = 0.0
        AND speculative_retry = '99PERCENTILE'
        AND comment = ''
        AND caching = { 'keys': 'ALL', 'rows_per_partition': 'NONE' }
        AND compaction = { 'max_threshold': '32', 'min_threshold': '4', 'class': 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy' }
        AND compression = { 'chunk_length_in_kb': '64', 'class': 'org.apache.cassandra.io.compress.LZ4Compressor' }
        AND cdc = false
        AND extensions = {  };

Step-7: Login to the database and create a table using that DDL.

    apiadmin@cqlsh:coopersdev> use students_details;
    apiadmin@cqlsh:students_details> CREATE TABLE IF NOT EXISTS students_details.cricket (
                        ...         playerid uuid PRIMARY KEY,
                        ...         city text,
                        ...         firstname text,
                        ...         lastname text,
                        ...         state text)
                        ...         WITH ID = 88128dc0-960d-11ea-947b-39646348bb4f
                        ...         AND bloom_filter_fp_chance = 0.01
                        ...         AND dclocal_read_repair_chance = 0.1
                        ...         AND crc_check_chance = 1.0
                        ...         AND default_time_to_live = 0
                        ...         AND gc_grace_seconds = 864000
                        ...         AND min_index_interval = 128
                        ...         AND max_index_interval = 2048
                        ...         AND memtable_flush_period_in_ms = 0
                        ...         AND read_repair_chance = 0.0
                        ...         AND speculative_retry = '99PERCENTILE'
                        ...         AND comment = ''
                        ...         AND caching = { 'keys': 'ALL', 'rows_per_partition': 'NONE' }
                        ...         AND compaction = { 'max_threshold': '32', 'min_threshold': '4', 'class': 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy' }
                        ...         AND compression = { 'chunk_length_in_kb': '64', 'class': 'org.apache.cassandra.io.compress.LZ4Compressor' }
                        ...         AND cdc = false
                        ...         AND extensions = {  };
apiadmin@cqlsh:students_details>

Step 8: copy all the files on snapshot folder to existing cricket table folder.

cassandra@node1:~/data/students_details/cricket-88128dc0960d11ea947b39646348bb4f/snapshots/dropped-1589479603749-cricket$ pwd
/home/cassandra/data/students_details/cricket-88128dc0960d11ea947b39646348bb4f/snapshots/dropped-1589479603749-cricket
cassandra@node1:~/data/students_details/cricket-88128dc0960d11ea947b39646348bb4f/snapshots/dropped-1589479603749-cricket$ cp * /home/cassandra/data/students_details/cricket-88128dc0960d11ea947b39646348bb4f
cassandra@node1:~/data/students_details/cricket-88128dc0960d11ea947b39646348bb4f/snapshots/dropped-1589479603749-cricket$ cd /home/cassandra/data/students_details/cricket-88128dc0960d11ea947b39646348bb4f
cassandra@node1:~/data/students_details/cricket-88128dc0960d11ea947b39646348bb4f$ ls -lrth
total 44K
drwxrwxr-x 2 cassandra cassandra    6 May 14 18:05 backups
drwxrwxr-x 3 cassandra cassandra   43 May 14 18:06 snapshots
-rw-rw-r-- 1 cassandra cassandra  891 May 14 18:11 schema.cql
-rw-rw-r-- 1 cassandra cassandra   92 May 14 18:11 md-1-big-TOC.txt
-rw-rw-r-- 1 cassandra cassandra   92 May 14 18:11 md-1-big-Summary.db
-rw-rw-r-- 1 cassandra cassandra 4.7K May 14 18:11 md-1-big-Statistics.db
-rw-rw-r-- 1 cassandra cassandra   61 May 14 18:11 md-1-big-Index.db
-rw-rw-r-- 1 cassandra cassandra   16 May 14 18:11 md-1-big-Filter.db
-rw-rw-r-- 1 cassandra cassandra    9 May 14 18:11 md-1-big-Digest.crc32
-rw-rw-r-- 1 cassandra cassandra  179 May 14 18:11 md-1-big-Data.db
-rw-rw-r-- 1 cassandra cassandra   43 May 14 18:11 md-1-big-CompressionInfo.db
-rw-rw-r-- 1 cassandra cassandra   31 May 14 18:11 manifest.json
cassandra@node1:~/data/students_details/cricket-88128dc0960d11ea947b39646348bb4f$

Step 9: start restoring table data using sstableloader by using below command

cassandra@node1:~$ sstableloader -d 10.213.61.21 -username cassandra --password cassandra /home/cassandra/data/students_details/cricket-d3576f60960f11ea947b39646348bb4f/snapshots
    Established connection to initial hosts
    Opening sstables and calculating sections to stream

    Summary statistics:
       Connections per host    : 1
       Total files transferred : 0
       Total bytes transferred : 0.000KiB
       Total duration          : 2920 ms
       Average transfer rate   : 0.000KiB/s
       Peak transfer rate      : 0.000KiB/s

Step-10: The table was restored successfully. Please verify.

playerid                             | city      | firstname | lastname  | state
--------------------------------------+-----------+-----------+-----------+------------
 d7b12c90-960f-11ea-947b-39646348bb4f | Berhampur |     Rohit |    Sharma |     Odisha
 d7594890-960f-11ea-947b-39646348bb4f |     Delhi |     Virat |     Vholi |  New Delhi
 d7588540-960f-11ea-947b-39646348bb4f |    Mumbai |    Sachin | Pendulkar | Maharastra