Tair (Redis® OSS-Compatible):Bulk delete keys

(Recommended) Use SCAN and UNLINK

This method iteratively scans for and deletes keys that match a specific pattern. 

1. Save the following code as the scan_and_unlink.py script:

   import redis
   import sys
   
   def main(argv):
       if len(argv) < 4:
           print("Usage: python scan_and_del.py host port password match")
           sys.exit(-1)
   
       host = argv[1]
       port = argv[2]
       password = argv[3]
       match = argv[4]
       print("host: %s, port: %s, password: %s, match: %s\n" % (host, port, password, match))
   
       redis_cli = redis.StrictRedis(host=host, port=port, password=password)
       cursor = 0
       rnd = 1
   
       while rnd == 1 or cursor != 0:
           result = redis_cli.scan(cursor=cursor, match=match, count=1000)
           ret_cursor = result[0]
           ret_keys = result[1]
           num_keys = len(ret_keys)
           print("Deleted %d keys in round %d. Cursor: %d" % (num_keys, rnd, ret_cursor))
           if 0 != num_keys:
               ret_unlink = redis_cli.unlink(*ret_keys)
               print("unlink returned: %d, keys unlinked: %s" % (ret_unlink, ret_keys))
           cursor = ret_cursor
           rnd += 1
           print("")
   
   if __name__ == '__main__':
       main(sys.argv)

2. Run the following command to execute the script:

   python scan_and_unlink.py <host> <port> <password> "<key>" 

   Parameters:

   • host: The endpoint of the Redis instance.

   • port: The port number of the Redis instance. Default value: 6379.

   • password: The password used to connect to the Redis instance. For more information, see Connect to an instance.

   • key: The pattern used to match the keys you want to delete. For example, "test*" matches all keys with the test prefix, such as test1, test2, and test3.

     The following examples show how to use wildcards for pattern matching:

     • w?rld: Matches a five-character string that starts with w and ends with rld, such as world, warld, and wxrld.

     • w*rld: Matches any string that starts with w and ends with rld, such as wrld and woooorld.

     • w[ae]rld: Matches warld and werld, but not world.

     • w[^e]rld: Matches world and warld, but not werld.

     • w[a-b]rld: Matches warld and wbrld.

Use pipeline mode for high-throughput deletion

This method iteratively scans for keys that match a specific pattern and then uses a pipeline to send UNLINK commands in batch. This approach significantly reduces the Round-Trip Time (RTT).

1. Save the following code as the scan_and_unlink_pipe.py script:

   import redis
   import sys
   
   
   def main(argv):
       if len(argv) < 4:
           print("Usage: python scan_and_del_pipeline.py host port password match")
           sys.exit(-1)
   
       host = argv[1]
       port = int(argv[2])  # Convert port to integer
       password = argv[3]
       match = argv[4]
       print(f"host: {host}, port: {port}, password: {'*' * len(password)}, match: {match}\n")
   
       # After accumulating 1,000 keys, submit a DEL command through the pipeline. You can adjust this number as needed.
       pipeline_batch_size = 1000
       
       redis_cli = redis.StrictRedis(host=host, port=port, password=password, decode_responses=True)
       
       cursor = 0
       total_deleted_count = 0
       keys_to_delete = []
   
       print("Starting key scan...")
       # Use a 'while True' loop and exit when the cursor is 0.
       while True:
           # 1. Scan a batch of keys.
           cursor, keys = redis_cli.scan(cursor=cursor, match=match, count=1000)
   
           if keys:
               # 2. Collect the scanned keys into a list for deletion.
               keys_to_delete.extend(keys)
   
           # 3. When the deletion list reaches the batch size or the scan is complete, execute the deletion.
           if len(keys_to_delete) >= pipeline_batch_size or cursor == 0:
               if keys_to_delete:
                   print(f"Accumulated {len(keys_to_delete)} keys. Preparing to delete via Pipeline...")
   
                   # --- Pipeline -----------
                   pipe = redis_cli.pipeline(transaction=False, shard_hint=None)
                   pipe.delete(*keys_to_delete)
                   result = pipe.execute()
                   # -------------------------
   
                   deleted_in_batch = result[0]
                   total_deleted_count += deleted_in_batch
   
                   print(f"  -> Pipeline executed. Deleted {deleted_in_batch} keys in this batch.")
   
                   # Clear the deletion list to prepare for the next batch.
                   keys_to_delete = []
   
           # 4. If the scan is complete, exit the loop.
           if cursor == 0:
               break
   
       print(f"\nScan finished. Total keys deleted: {total_deleted_count}")
   
   
   if __name__ == '__main__':
       main(sys.argv)
   

2. Run the following command to execute the script:

   python scan_and_unlink_pipe.py <host> <port> <password> "<key>" 

   Parameters:

   • host: The endpoint of the Redis instance.

   • port: The port number of the Redis instance. Default value: 6379.

   • password: The password used to connect to the Redis instance. For more information, see Connect to an instance.

   • key: The pattern used to match the keys you want to delete. For example, "test*" matches all keys with the test prefix, such as test1, test2, and test3.

     The following examples show how to use wildcards for pattern matching:

     • w?rld: Matches a five-character string that starts with w and ends with rld, such as world, warld, and wxrld.

     • w*rld: Matches any string that starts with w and ends with rld, such as wrld and woooorld.

     • w[ae]rld: Matches warld and werld, but not world.

     • w[^e]rld: Matches world and warld, but not werld.

     • w[a-b]rld: Matches warld and wbrld.

Use KEYS and DEL

Run the following command to delete the keys that match the specified pattern:

redis-cli -h <host> -p <port> -a <password> KEYS "<key>" | xargs redis-cli -h <host> -p <port> -a <password> DEL

This command uses KEYS with a wildcard pattern to find all matching keys and then pipes them to xargs, which passes them to DEL for deletion.

Parameters:

• host: The endpoint of the Redis instance.

• port: The port number of the Redis instance. Default value: 6379.

• password: The password used to connect to the Redis instance. For more information, see Connect to an instance.

• key: The pattern used to match the keys you want to delete. For example, "test*" matches all keys with the test prefix, such as test1, test2, and test3.

  The following examples show how to use wildcards for pattern matching:

  • w?rld: Matches a five-character string that starts with w and ends with rld, such as world, warld, and wxrld.

  • w*rld: Matches any string that starts with w and ends with rld, such as wrld and woooorld.

  • w[ae]rld: Matches warld and werld, but not world.

  • w[^e]rld: Matches world and warld, but not werld.

  • w[a-b]rld: Matches warld and wbrld.

Sample command:

redis-cli -h r-bp127cu5tb*****.redis.rds.aliyuncs.com -a Test**** KEYS "keys*" | xargs redis-cli -h r-bp127cu5tb*****.redis.rds.aliyuncs.com -a Test**** DEL