this is the schema similar to what we have , they want to get user
connected - concurrent count for every say 1-5 minutes.
i am thinking will simple select will have performance issue or we can go
for materialized views ?
CREATE TABLE usr_session (
userid bigint,
session_usr text,
last_access_time timestamp,
login_time timestamp,
status int,
PRIMARY KEY (userid, session_usr)
) WITH CLUSTERING ORDER BY (session_usr ASC)
On Thu, Feb 6, 2020 at 2:09 PM Durity, Sean R <sean_r_dur...@homedepot.com>
wrote:
> Do you only need the current count or do you want to keep the historical
> counts also? By active users, does that mean some kind of user that the
> application tracks (as opposed to the Cassandra user connected to the
> cluster)?
>
>
>
> I would consider a table like this for tracking active users through time:
>
>
>
> Create table users_by_day (
>
> app_date date,
>
> hour integer,
>
> minute integer,
>
> user_count integer,
>
> longest_login_user text,
>
> longest_login_seconds integer,
>
> last_login datetime,
>
> last_login_user text )
>
> primary key (app_date, hour, minute);
>
>
>
> Then, your reporting can easily select full days or a specific, one-minute
> slice. Of course, the app would need to have a timer and write out the
> data. I would also suggest a TTL on the data so that you only keep what you
> need (a week, a year, whatever). Of course, if your reporting requires
> different granularities, you could consider a different time bucket for the
> table (by hour, by week, etc.)
>
>
>
>
>
> Sean Durity – Staff Systems Engineer, Cassandra
>
>
>
> *From:* Abdul Patel <abd786...@gmail.com>
> *Sent:* Thursday, February 6, 2020 1:54 PM
> *To:* user@cassandra.apache.org
> *Subject:* [EXTERNAL] Re: Running select against cassandra
>
>
>
> Its sort of user connected, app team needa number of active users
> connected say every 1 to 5 mins.
>
> The timeout at app end is 120ms.
>
>
>
>
>
> On Thursday, February 6, 2020, Michael Shuler <mich...@pbandjelly.org>
> wrote:
>
> You'll have to be more specific. What is your table schema and what is the
> SELECT query? What is the normal response time?
>
> As a basic guide for your general question, if the query is something sort
> of irrelevant that should be stored some other way, like a total row count,
> or most any SELECT that requires ALLOW FILTERING, you're doing it wrong and
> should re-evaluate your data model.
>
> 1 query per minute is a minuscule fraction of the basic capacity of
> queries per minute that a Cassandra cluster should be able to handle with
> good data modeling and table-relevant query. All depends on the data model
> and query.
>
> Michael
>
> On 2/6/20 12:20 PM, Abdul Patel wrote:
>
> Hi,
>
> Is it advisable to run select query to fetch every minute to grab data
> from cassandra for reporting purpose, if no then whats the alternative?
>
>
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