67. Don’t Try Update After didn’t Read DB
Value
Profile
- LastLoginTime
- UserName
- Host
- Name
68. Don’t Try Update After didn’t Read DB
Value EVENT: Update Only LastLoginTime
Profile
- LastLoginTime
- UserName
- Host
- Name
69. Don’t Try Update After didn’t Read DB
Value EVENT: Update Only LastLoginTime
Profile Read Cache: User Profile
- LastLoginTime
- UserName
- Host
- Name
70. Don’t Try Update After didn’t Read DB
Value EVENT: Update Only LastLoginTime
Profile Read Cache: User Profile
- LastLoginTime
- UserName
Update Data & DB
- Host
- Name
Just Save Cache
71. Don’t Try Update After didn’t Read DB
Value EVENT: Update Only LastLoginTime
Profile Read Cache: User Profile
- LastLoginTime
- UserName
Update Data & DB
- Host
- Name
Just Save Cache
It Makes Race Condition
108. Memcached In Facebook
• Facebook and Google and Many Companies
• Facebook
– 하루 Login 5억명(한달에 8억명)(최신, 밑에는 작년 2010/04자료)
– 활성 사용자 7,000만
– 사용자 증가 비율 4일에 100만명
– Web 서버 10,000 대, Web Request 초당 2000만번
– Memcached 서버 805대 -> 15TB, HitRate: 95%
– Mysq server 1,800 대 Master/Slave(각각, 900대)
• Mem: 25TB, SQL Query 초당 50만번