Hello,
The jinja2 loop you've defined will try to download source files like documents-2.json-0.bz2, documents-2.json-1.bz2 etc.
Since you are using the same base-url as the upstream geonames, you end up referencing files that don't exist, which you can easily check yourself with:
curl http://benchmarks.elasticsearch.org.s3.amazonaws.com/corpora/geonames/documents-2.json-0.bz2
<?xml version="1.0" encoding="UTF-8"?>
<Error><Code>NoSuchKey</Code><Message>The specified key does not exist.</Message><Key>corpora/geonames/documents-2.json-0.bz2</Key><RequestId>037E3BB5A46782DE</RequestId><HostId>7oagYu1Ol6QaaxOINX+0VFpGzQ0o9enTiz/uDRIHsEDwTaNVQH3tqV+MWkuvi8/gvSHT4Bo6MXc=</HostId></Error>
I am surprised you didn't get a 404 while running this, as such files don't exist.
If you want to use a larger corpus by repeating geonames 10 times, you can simply download locally and concatenate it in a larger file and either provide the full path to this in source-file or upload it to some location you control and change base-url accordingly. Details in https://esrally.readthedocs.io/en/latest/track.html#corpora.
Rgs,
Dimitris