In a Feeds architecture(like Facebook news or Twitter), how to make the feeds counts consistent with the feeds lists' length? -


i designing feeds system, 1 can post news, , others can see each other's news, twitter.

now i'm saving news in hbase, , cache them in redis. approach has o(1) insert, update , remove, "count" hard achieve:

if save separate count in redis, , increasing/decreasing upon insertion/removal, value can not consistent real list length in hbase: 1 single failure on network or other exception can make value wronged.

if count hbase, it's time consuming.

what design choice should make?

hbase provides support atomic counters: instead of maintaining count in redis , relying on multiple system can use hbase (in real-time).

just insert post, , if went ok, increment counter. can have multiple counters track total posts + posts per day, week, month, year... it's powerful feature.

for more info hbase book has few pages dedicated counters, also, can check increment example.


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