This readme contains a quickstart guide, and details of how the modules interact with each other. For a guide to configuring each module, there is a README in each of the modules' playbooks
directory.
To customise the model, we recommend following the guidance found in the README in the sql/custom
directory.
SQL-runner must be installed, and a dataset of web events from the Snowplow Javascript tracker must be available in the database.
First, fill in the connection details for the target database in the relevant template in .scripts/template/redshift.yml.tmpl
.
Password can be left as a PASSWORD_PLACEHOLDER
, and set as an environment variable or passed as an argument to the run_playbooks script. See the README in .scripts
for more detail.
Variables in each module's playbook can also optionally be configured also. See each playbook directory's README for more detail on configuration of each module.
To run the entire standard model, end to end:
bash .scripts/run_config.sh -b ~/pathTo/sql-runner -c web/v1/redshift/sql-runner/configs/datamodeling.json -t .scripts/templates/redshift.yml.tmpl;
See the README in the .scripts/
directory for more details.
A guide to creating custom modules can be found in the README of the sql/custom/
directory of the relevant model. Each custom module created must consist of a set of sql files and a playbook, or set of playbooks. The helper scripts described above can also be used to run custom modules.
Python3 is required.
Install Great Expectations and dependencies, and configure a datasource:
cd .test
pip3 install -r requirements.txt
great_expectations datasource new
Follow the CLI guide to configure access to your database. The configuration for your datasource will be generated in .test/great_expectations/config/config_variables.tml
- these values can be replaced by environment variables if desired.
To run the test suites alone:
bash run_test.sh redshift v1 perm_tables {credentials (optional)}
bash run_test.sh redshift v1 temp_tables {credentials (optional)}
To run an entire run of the standard model, and tests end to end:
bash e2e.sh {path_to_sql_runner} redshift v1 {credentials (optional)}
To run a full battery of ten runs of the standard model, and tests:
bash pr_check.sh {path_to_sql_runner} redshift v1 {credentials (optional)}
Check out the Great Expectations documentation for guidance on using it to run existing test suites directly, create new expectations, use the profiler, and autogenerate data documentation.
Quickstart to create a new test suite:
great_expectations suite new
Inputs: atomic tables, {{.output_schema}}.base_event_id_manifest
, {{.output_schema}}.base_session_id_manifest
Persistent Outputs: {{.scratch_schema}}.events_staged
,
Temporary Outputs: {{.scratch_schema}}.events_this_run
, {{.scratch_schema}}.base_duplicates_this_run
The base module executes the incremental logic of the model - it retrieves all events for sessions with new data, deduplicates, and adds the page_view_id.
The base module's 'complete' playbook (99-base-complete.yml.tmpl
) updates the two relevant manifests, and cleans up temporary tables. The lifecycle of the {{.scratch_schema}}.events_staged
table is completed by the 99-page-views-complete.yml.tmpl
step (of the subsequent module).
A record of the duplicates removed for the run is logged in the {{.scratch_schema}}.base_duplicates_this_run
table. Note that the base_duplicates_this_run table is dropped and recomputed every run, users interested in permanently logging them should create a custom module to handle this.
The {{.scratch_schema}}.events_this_run
table contains all events relevant only to this run of the model (since the last time the 99-base-complete.yml.tmpl
playbook has run). This table is dropped and recomputed every run of the module, regardless of whether another module has used the data.
If there is a requirement that a custom module consumes data more frequently than the page views module, the {{.scratch_schema}}.events_this_run
table may be used for this purpose.
The {{.scratch_schema}}.events_staged
table is incrementally updated to contain all events relevant to any run of the base module since the last time the page views module consumed it (ie since the last time the 99-page-views-complete.yml.tmpl
has run). This allows one to run the base module more frequently than the page views module (if, for example, a custom module reads from events_this_run).
Detail on configuring the base module's playbook can be found in the relevant playbook directory's README.
Inputs: atomic tables, {{.scratch_schema}}.events_staged
Persistent Outputs: {{.output_schema}}.page_views
, {{.scratch_schema}}.page_views_staged
Temporary Outputs: {{.scratch_schema}}.page_views_this_run
, {{.scratch_schema}}.pv_page_view_id_duplicates_this_run
The page views module takes {{.scratch_schema}}.events_staged
as its input, deduplicates on page_view_id, calculates the standard page views model, and updates the production page_views table. It also produces the {{.scratch_schema}}.page_views_staged
and {{.scratch_schema}}.page_views_this_run
tables.
The page views module's 'complete' playbook 99-page-views-complete.yml.tmpl
truncates the {{.scratch_schema}}.events_staged
table, and cleans up temporary tables. The lifecycle of the {{.scratch_schema}}.page_views_staged
table is completed by the 99-sessions-complete.yml.tmpl
step (of the subsequent module).
A record of the duplicates removed for the run is logged in the {{.scratch_schema}}.pv_page_view_id_duplicates_this_run
table. Note that the {{.scratch_schema}}.pv_page_view_id_duplicates_this_run
table is dropped and recomputed every run, users interested in permanently logging them should create a custom module to handle this.
The {{.scratch_schema}}.page_views_this_run
table contains all events relevant only to this run of the model (since the last time the 99-page-views-complete.yml.tmpl
playbook has run). This table is dropped and recomputed every run of the module, regardless of whether another module has used the data.
If there is a requirement that a custom module consumes data more frequently than the sessions module, the {{.scratch_schema}}.page_views_this_run
table may be used for this purpose.
The {{.scratch_schema}}.page_views_staged
table is incrementally updated to contain all events relevant to any run of the page views module since the last time the sessions module consumed it (ie since the last time the 99-sessions-complete.yml.tmpl
playbook has run). This allows one to run the page views module more frequently than the sessions module (if, for example, a custom module reads from page_views_this_run).
The page views module also contains optional add-on steps. These can be configured to run or not based on which enrichments the user has enabled, and wishes to include in the model.
Detail on configuring the page views module's playbook can be found in the relevant playbook directory's README.
Inputs: {{.scratch_schema}}.page_views_staged
Persistent Outputs: {{.output_schema}}.sessions
, {{.scratch_schema}}.sessions_userid_manifest_staged
Temporary Outputs: {{.scratch_schema}}.sessions_this_run
The sessions module takes {{.scratch_schema}}.page_views_staged
as its input, calculates the standard sessions model, and updates the production sessions table. It also produces the {{.scratch_schema}}.sessions_userid_manifest_staged
and {{.scratch_schema}}.sessions_this_run{{.entropy}}
tables.
Unlike the other modules, the sessions module outputs a manifest of IDs as its staged table rather than a table containing all unprocessed data - this is due to the fact that the users step requires a longer lookback than the incremental structure contains, so there are obviously efficiency limitations.
The sessions module's 'complete' playbook 99-sessions-complete.yml.tmpl
truncates the {{.scratch_schema}}.page_views_staged
table, and cleans up temporary tables. The lifecycle of the {{.scratch_schema}}.sessions_userid_manifest_staged
table is completed by the 99-users-complete.yml.tmpl
step (of the subsequent module).
The {{.scratch_schema}}.sessions_this_run
table contains all events relevant only to this run of the model (since the last time the 99-sessions-complete.yml.tmpl
playbook has run). This table is dropped and recomputed every run of the module, regardless of whether another module has used the data.
If there is a requirement that a custom module consumes data more frequently than the users module, the {{.scratch_schema}}.sessions_this_run
table may be used for this purpose.
The {{.scratch_schema}}.sessions_userid_manifest_staged
table is incrementally updated to contain all IDs relevant to any run of the sessions module since the last time the users module consumed it (ie since the last time the 99-users-complete.yml.tmpl
playbook has run). This allows one to run the sessions module more frequently than the users module (if, for example, a custom module reads from sessions_this_run and is more frequent than the page views module).
Detail on configuring the sessions module's playbook can be found in the relevant playbook directory's README.
Inputs: {{.scratch_schema}}.sessions_userid_manifest_staged
, {{.output_schema}}.users_manifest
Persistent Outputs: {{.output_schema}}.users
Temporary Outputs: {{.scratch_schema}}.users_this_run
The sessions module takes {{.scratch_schema}}.sessions_userid_manifest_staged
as its input, alongside the {{.output_schema}}.users_manifest
table (which is self-maintained within the users module). It calculates the standard users model, and updates the production users table. It also produces the {{.scratch_schema}}.users_this_run
table.
Unlike the other modules, the users module doesn't take an input that contains all information required to run the module. It uses the {{.output_schema}}.users_manifest
table to manage efficiency, and queries the sessions table to process data as far back in history as is required.
The users module's 'complete' playbook 99-users-complete.yml.tmpl
truncates the {{.scratch_schema}}.sessions_userid_manifest_staged
table, commits to the {{.output_schema}}.users_manifest
and cleans up temporary tables. There is no _staged
table for this module, as there are no subsequent modules.
The {{.scratch_schema}}.users_this_run
table contains all events relevant only to this run of the model (since the last time the 99-users-complete.yml.tmpl
playbook has run). This table is dropped and recomputed every run of the module, regardless of whether another module has used the data.
Detail on configuring the users module's playbook can be found in the relevant playbook directory's README.
This version of the model (>1.1.0) excludes duplicated event_ids and page_view_ids. Ideally in the future it will provide standard options for handling them, however because customisations of this model involve queries on federated atomic tables, the safest option for a first version is to exclude them.
If there is a need to handle duplicates, this can be done by adding a custom module to the base level of aggregation - take good care to manage the possibility of introducing duplicates downstream if doing so.
Normally, one would expect less than 1% duplicates in the dataset. If the requirement to handle duplicates arises from the fact that there is a large proportion of them, users are advised to first investigate the source of duplicates and attempt to address the issue upstream of the data models - a high proportion of duplicates can be indicative of a more significant issue in tracking or configuration of the pipeline.