event log - User point system in Cassandra -

i want design system user point. main 2 points of system point , log.

i want use cassandra store data. 2 reason:

1. cassandra provides counter feature can use store point.
2. the log of point changing may have think scale of storage. cassandra can scaled.

the basic data sturcture:

// row name: user_id, values: {     point: {         name: point,         values: 1000     },     log: {         name: log,         values: {             log_timestamp: {                  name: timestamp,                  values: xxxx             },             log_timestamp: {                  name: timestamp,                  values: xxxx             },             log_timestamp: {                  name: timestamp,                  values: xxxx             },             ……         }     } } 

my question is:

is there problem if log many enough?

@lifei

what want somehow table with:

1. row key (partition key) = userid
2. 1 point counter
3. 1 log collection many log_timestamp possible

it indeed easy create table this:

create table logs (   userid: int,   log_timestamp long, //timestamp   value text,   primary key (userid,log_timestamp) ); 

it clustered entity (wide row) maximum of 2 billions of log_timestamp/value couples.

for point counter, unfortunately have create column family store because cassandra not allow mixing counter value other types.