> After about 1-2K inserts I get significant performance decrease. A decrease in performance doing what ?
Cheers ----------------- Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 19/04/2013, at 4:43 AM, Oleksandr Petrov <oleksandr.pet...@gmail.com> wrote: > Hi, > > I'm trying to persist some event data, I've tried to identify the bottleneck, > and it seems to work like that: > > If I create a table with primary key based on (application, environment, type > and emitted_at): > > CREATE TABLE events (application varchar, environment varchar, type varchar, > additional_info map<varchar, varchar>, hostname varchar, emitted_at > timestamp, > PRIMARY KEY (application, environment, type, emitted_at)); > > And insert events via CQL, prepared statements: > > INSERT INTO events (environment, application, hostname, emitted_at, type, > additional_info) VALUES (?, ?, ?, ?, ?, ?); > > Values are: "local" "analytics" "noname" #inst > "2013-04-18T16:37:02.723-00:00" "event_type" {"some" "value"} > > After about 1-2K inserts I get significant performance decrease. > > I've tried using only emitted_at (timestamp) as a primary key, OR writing > additional_info data as a serialized JSON (varchar) instead of Map. Both > scenarios seem to solve the performance degradation. > > I'm using Cassandra 1.2.3 from DataStax repository, running it on 2-core > machine with 2GB Ram. > > What could I do wrong here? What may cause performance issues?.. > Thank you > > > -- > alex p
