Command line Cassandra query runner that supports walking and querying
multiple partitions using a simple syntax. Results are printed as JSON
objects that are friendly to tools like jq.
Given the following table
sql
create table mydb.user_click (
bin text,
country text,
url text,
ip inet,
clicked_at timestamp,
primary key ((bin, country), url, ip))
with clustering order by (url asc, ip asc);
where bin is a date string like 2020-01-13.
You can run multiple queries against all target partitions like this:
shell
kass -h localhost "select bin, country, count(*) from user_click where bin=? and country=? and url='http://myawsome-web-product.com/landing.html'" \
2019-12-01..2020-01-10/1d nz,us,au,cn
This will query the user_click table for the counts of user clicks
of the specified URL from countries NZ, US, AU and CN, between
2019-12-01 and 2020-01-10. It walks through all the combinations of
the provided dates (as specified by the range) and countries (comma
separated list) and runs queries against these partitions in parallel
(with configurable parallelism).
Results are encoded in JSON for easier post-processing,
e.g. aggregation using jq.
json
{"bin":"2019-12-01","country":"au","count":1}
{"bin":"2019-12-01","country":"us","count":2}
{"bin":"2019-12-01","country":"cn","count":1}
{"bin":"2019-12-02","country":"au","count":1}
{"bin":"2019-12-02","country":"us","count":2}
{"bin":"2019-12-26","country":"au","count":1}
{"bin":"2019-12-26","country":"us","count":2}
{"bin":"2019-12-27","country":"cn","count":1}
{"bin":"2019-12-31","country":"cn","count":1}
{"bin":"2020-01-07","country":"cn","count":1}
{"bin":"2020-01-08","country":"nz","count":3}
{"bin":"2020-01-09","country":"nz","count":3}
{"bin":"2020-01-08","country":"au","count":1}
{"bin":"2020-01-08","country":"cn","count":1}
{"bin":"2020-01-08","country":"us","count":2}
{"bin":"2020-01-09","country":"us","count":2}
{"bin":"2020-01-09","country":"cn","count":1}
{"bin":"2020-01-09","country":"au","count":1}
With Cassandra, table schemas are often designed around the query
pattern and you really need to follow that pattern to be able to
efficiently query the data. This means it is needed to run the same
query against multiple partitions when you want to query the data
differently. In the above example, you can't do something like
bin>'2019-12-01' and bin<'2020-01-01 and county in ('nz', 'us', 'au',
'cn') as you would in a SQL database. This is especially common when
working with time series data.
I often find myself writing bash scripts that does essentially the
same thing but uses cqlsh. I couldn't find a similar tool so I
decided to make one and also learn Rust in the process.
It is based on the pure Rust Cassandra driver cdrs.
cargoComing soon
Clone the repo and run
shell
cargo install --path .
add --force if you want to upgrade
shell
cargo install --path . --force
``` shell $ kass --help Kass 0.1.0 Cassandra multi-partition query runner
USAGE:
kass [OPTIONS]
OPTIONS:
-C, --color
ARGS:
More to come
Coming soon