Prints the number of bytes per db in Redis

redis-db-mem.py

import sys
import redis

if len(sys.argv) == 0:
    print "Usage: redis-db-mem.py HOST [PORT]"
    sys.exit(2)

host = sys.argv[1]
if len(sys.argv) > 2:
    port = int(sys.argv[2])
else:
    port = 6379

info = redis.StrictRedis(host, port).info()
dbs = [int(_[2:]) for _ in info if _[0:2] == 'db']
dbs.sort()
total_bytes = 0
for db in dbs:
    r = redis.StrictRedis(host, port, db=db)
    key_count = 0
    byte_count = 0
    for key in r.scan_iter('*'):
        object_dump = r.dump(key)
        if object_dump:
            key_count += 1
            byte_count += len(object_dump) - 8
    total_bytes += byte_count
    print "db %d: %d objects, %d bytes" % (db, key_count, byte_count)

print "total: %d bytes"

This is estimated using the DUMP command. On my servers, I would need to 4X with the result to get the actual memory usage.

Well, I expected this to make redis unhappy, but it was enough to take down the server. Not sure which line of code did it, but I'm not ready to figure out. Damn. Looked useful.