Writing Data to Riak TS

Now that you’ve planned and activated your Riak TS table, you are ready to write data to it.

Writing Data

Riak TS allows you to write multiple rows of data at a time. To demonstrate, we’ll use the example table from earlier:

CREATE TABLE GeoCheckin
(
   myfamily    varchar   not null,
   myseries    varchar   not null,
   time        timestamp not null,
   weather     varchar   not null,
   temperature double,
   PRIMARY KEY (
     (myfamily, myseries, quantum(time, 15, 'm')),
     myfamily, myseries, time
   )
)

To write data to your table, put the data in a list:

{ok, Pid} = riakc_pb_socket:start_link("myriakdb.host", 10017).
riakc_ts:put(Pid, "GeoCheckin", [[<<"family1">>, <<"series1">>, 1234567, <<"hot">>, 23.5], [<<"family2">>, <<"series99">>, 1234567, <<"windy">>, 19.8]]).

RiakClient client = RiakClient.newClient(10017, "myriakdb.host");
List<Row> rows = Arrays.asList(
    new Row(new Cell("family1"), new Cell("series1"),
            Cell.newTimestamp(1234567), new Cell("hot"), new Cell(23.5)),

    new Row(new Cell("family2"), new Cell("series99"),
            Cell.newTimestamp(1234567), new Cell("windy"), new Cell(19.8)));

Store storeCmd = new Store.Builder("GeoCheckin").withRows(rows).build();
client.execute(storeCmd);

import datetime
from riak.client import RiakClient

# NB: modify 'host' and 'pb_port' to match your installation
client = RiakClient(host='myriakdb.host', pb_port=8087)

fiveMins = datetime.timedelta(0, 300)
ts0 = datetime.datetime(2015, 1, 1, 12, 0, 0)
ts1 = ts0 + fiveMins

table = client.table('GeoCheckin')
rows = [
    ['family1', 'series1', ts0, 'hot', 23.5],
    ['family1', 'series1', ts1, 'windy', 19.8]
]
ts_obj = table.new(rows)
print "Store result:", ts_obj.store()

client = Riak::Client.new 'myriakdb.host', pb_port: 10017
submission = Riak::TimeSeries::Submission.new client, "GeoCheckin"
submission.measurements = [["family1", "series1", 1234567, "hot", 23.5], ["family2", "series99", 1234567, "windy", 19.8]]
submission.write!

Note on validation:

Riak TS 1.0.0 does not have client-side insertion validation. Please take caution when creating data to insert by ensuring that each row’s cells match the order/types of the table, and that you do not create a null-value cell for a non-nullable column.

If all of the data are correctly written the response is: ok in Erlang, and will not raise an error in Ruby.

If some of the data failed to write, an RpbErrorResp error occurs with a number of failures. In the event that your write fails, you should:

  1. Do a binary search with half the data, then the other half, and etc. to pinpoint the problem; or
  2. Write the data one at a time until one fails.

You could also try the original write again. Failures may be transitory when servers are temporarily unable to talk to each other.

Guidelines

  • Batches should not be too large. In our testing, 100 rows per write is a sweet spot, but you should expect different results depending on your hardware and schema.
  • Writes will assume that columns are in the same order they’ve been declared in the table.
  • Timestamps should be in Unix epoch/UTC milliseconds.

Next Steps

Now that you’ve written data to your tables, you can query your data.