docs: New concurrency pages and env vars (#9323)

Author: igorlukanin

DEPRECATION.md

@@ -64,6 +64,7 @@ features:
 | Removed    | [`initApp` hook](#initapp-hook)                                                                                                   | v0.35.0    | v0.35.0   |
 | Removed    | [`/v1/run-scheduled-refresh` REST API endpoint](#v1run-scheduled-refresh-rest-api-endpoint)                                       | v0.35.0    | v0.36.0   |
 | Deprecated | [Node.js 18](#nodejs-18)                                                                                                          | v0.36.0    |           |
+| Deprecated | [`CUBEJS_SCHEDULED_REFRESH_CONCURRENCY`](#cubejs_scheduled_refresh_concurrency) | v1.2.7 | |
 
 ### Node.js 8
 
@@ -391,3 +392,9 @@ API](https://cube.dev/docs/product/apis-integrations/orchestration-api) and
 
 Node.js 18 reaches [End of Life on April 30, 2025][link-nodejs-eol]. This means
 no more updates. Please upgrade to Node.js 20 or higher.
+
+### `CUBEJS_SCHEDULED_REFRESH_CONCURRENCY`
+
+**Deprecated in Release: v1.2.7**
+
+This environment variable was renamed to [`CUBEJS_SCHEDULED_REFRESH_QUERIES_PER_APP_ID`](https://cube.dev/docs/reference/configuration/environment-variables#cubejs_scheduled_refresh_queries_per_app_id). Please use the new name.

docs/pages/product/caching/_meta.js

@@ -2,6 +2,7 @@ module.exports = {
   "getting-started-pre-aggregations": "Getting started with pre-aggregations",
   "using-pre-aggregations": "Using pre-aggregations",
   "matching-pre-aggregations": "Matching pre-aggregations",
+  "refreshing-pre-aggregations": "Refreshing pre-aggregations",
   "lambda-pre-aggregations": "Lambda pre-aggregations",
   "running-in-production": "Running in production"
 }

docs/pages/product/caching/refreshing-pre-aggregations.mdx

@@ -0,0 +1,21 @@
+# Refreshing pre-aggregations
+
+_Pre-aggregation refresh_ is the process of building pre-aggregations and updating
+them with new data. Pre-aggregation refresh is the responsibility of the _refresh
+worker_.
+
+## Configuration
+
+You can use the following environment variables to configure the refresh worker
+behavior:
+
+- `CUBEJS_REFRESH_WORKER` (see also `CUBEJS_PRE_AGGREGATIONS_BUILDER`)
+- `CUBEJS_PRE_AGGREGATIONS_SCHEMA`
+- `CUBEJS_SCHEDULED_REFRESH_TIMEZONES`
+- `CUBEJS_DB_QUERY_TIMEOUT`
+- `CUBEJS_REFRESH_WORKER_CONCURRENCY` (see also `CUBEJS_CONCURRENCY`)
+- `CUBEJS_SCHEDULED_REFRESH_QUERIES_PER_APP_ID`
+- `CUBEJS_DROP_PRE_AGG_WITHOUT_TOUCH`
+
+
+[ref-multitenancy]: /product/configuration/advanced/multitenancy

docs/pages/product/configuration/_meta.js

@@ -1,5 +1,7 @@
 module.exports = {
   "data-sources": "Data sources",
   "visualization-tools": "Visualization tools",
-  "advanced": "Advanced"
+  "multiple-data-sources": "Multiple data sources",
+  "concurrency": "Concurrency",
+  "multitenancy": "Multitenancy"
 }

docs/pages/product/configuration/concurrency.mdx

@@ -0,0 +1,90 @@
+# Querying concurrency
+
+All queries to [data APIs][ref-data-apis] are processed asynchronously via a _query
+queue_. It allows to optimize the load and increase querying performance.
+
+## Query queue
+
+The query queue allows to deduplicate queries to API instances and insulate upstream
+data sources from query spikes. It also allows to execute queries to data sources
+concurrently for increased performance.
+
+By default, Cube uses a _single_ query queue for queries from all API instances and
+the refresh worker to all configured data sources.
+
+<ReferenceBox>
+
+You can read more about the query queue in the [this blog post](https://cube.dev/blog/how-you-win-by-using-cube-store-part-1#query-queue-in-cube).
+
+</ReferenceBox>
+
+### Multiple query queues
+
+You can use the [`context_to_orchestrator_id`][ref-context-to-orchestrator-id]
+configuration option to route queries to multiple queues based on the security
+context.
+
+<WarningBox>
+
+If you're configuring multiple connections to data sources via the [`driver_factory`
+configuration option][ref-driver-factory], you __must__ also configure
+`context_to_orchestrator_id` to ensure that queries are routed to correct queues.
+
+</WarningBox>
+
+## Data sources
+
+Cube supports various kinds of [data sources][ref-data-sources], ranging from cloud
+data warehouses to embedded databases. Each data source scales differently,
+therefore Cube provides sound defaults for each kind of data source out-of-the-box.
+
+### Data source concurrency
+
+By default, Cube uses the following concurrency settings for data sources:
+
+| Data source | Default concurrency |
+| --- | --- |
+| [Amazon Athena][ref-athena] | 10 |
+| [Amazon Redshift][ref-redshift] | 5 |
+| [Apache Pinot][ref-pinot] | 10 |
+| [ClickHouse][ref-clickhouse] | 10 |
+| [Databricks][ref-databricks] | 10 |
+| [Firebolt][ref-firebolt] | 10 |
+| [Google BigQuery][ref-bigquery] | 10 |
+| [Snowflake][ref-snowflake] | 8 |
+| All other data sources | 5 or [less, if specified in the driver][link-github-data-source-concurrency] |
+
+You can use the `CUBEJS_CONCURRENCY` environment variable to adjust the maximum
+number of concurrent queries to a data source. It's recommended to use the default
+configuration unless you're sure that your data source can handle more concurrent
+queries.
+
+### Connection pooling
+
+For data sources that support connection pooling, the maximum number of concurrent
+connections to the database can also be set by using the `CUBEJS_DB_MAX_POOL`
+environment variable. If changing this from the default, you must ensure that the
+new value is greater than the number of concurrent connections used by Cube's query
+queues and the refresh worker.
+
+## Refresh worker
+
+By default, the refresh worker uses the same concurrency settings as API instances.
+However, you can override this behvaior in the refresh worker
+[configuration][ref-preagg-refresh].
+
+
+[ref-data-apis]: /product/apis-integrations
+[ref-data-sources]: /product/configuration/data-sources
+[ref-context-to-orchestrator-id]: /reference/configuration/config#context_to_orchestrator_id
+[ref-driver-factory]: /reference/configuration/config#driver_factory
+[ref-preagg-refresh]: /product/caching/refreshing-pre-aggregations#configuration
+[ref-athena]: /product/configuration/data-sources/aws-athena
+[ref-clickhouse]: /product/configuration/data-sources/clickhouse
+[ref-databricks]: /product/configuration/data-sources/databricks-jdbc
+[ref-firebolt]: /product/configuration/data-sources/firebolt
+[ref-pinot]: /product/configuration/data-sources/pinot
+[ref-redshift]: /product/configuration/data-sources/aws-redshift
+[ref-snowflake]: /product/configuration/data-sources/snowflake
+[ref-bigquery]: /product/configuration/data-sources/google-bigquery
+[link-github-data-source-concurrency]: https://github.com/search?q=repo%3Acube-js%2Fcube+getDefaultConcurrency+path%3Apackages%2Fcubejs-&type=code

docs/pages/product/configuration/data-sources.mdx

@@ -8,8 +8,9 @@ redirect_from:
 
 Choose a data source to get started with below.
 
-Note that Cube also supports connecting to [multiple data
-sources][ref-config-multi-data-src] out of the box.
+You can also connect [multiple data sources][ref-config-multi-data-src] at the same
+time and adjust the [concurrency settings][ref-data-source-concurrency] for data
+sources.
 
 ## Data warehouses
 
@@ -251,28 +252,9 @@ users on the [Enterprise Premier](https://cube.dev/pricing) product tier.
 
 </InfoBox>
 
-## Concurrency and pooling
-
-<InfoBox>
-
-All Cube database drivers come with presets for concurrency and pooling that
-work out-of-the-box. The following information is included as a reference.
-
-</InfoBox>
-
-For increased performance, Cube uses multiple concurrent connections to
-configured data sources. The `CUBEJS_CONCURRENCY` environment variable controls
-concurrency settings for query queues and the refresh scheduler as well as the
-maximum concurrent connections.
-
-For databases that support connection pooling,
-the maximum number of concurrent connections to the database can also be set by
-using the `CUBEJS_DB_MAX_POOL` environment variable; if changing this from the
-default, you must ensure that the new value is greater than the number of
-concurrent connections used by Cube's query queues and refresh scheduler.
-
 
 [ref-config-multi-data-src]: /product/configuration/advanced/multiple-data-sources
 [ref-driver-factory]: /reference/configuration/config#driver_factory
 [ref-duckdb]: /product/configuration/data-sources/duckdb
-[link-github-packages]: https://github.com/cube-js/cube/tree/master/packages
+[link-github-packages]: https://github.com/cube-js/cube/tree/master/packages
+[ref-data-source-concurrency]: /product/configuration/concurrency#data-sources

docs/pages/product/configuration/data-sources/aws-athena.mdx

@@ -1,9 +1,4 @@
----
-redirect_from:
-  - /config/databases/aws-athena
----
-
-# AWS Athena
+# Amazon Athena
 
 ## Prerequisites
 
@@ -39,7 +34,7 @@ Configuration</Btn> in your deployment.
 
 </InfoBox>
 
-In Cube Cloud, select **AWS Athena** when creating a new deployment and fill in
+In Cube Cloud, select AWS Athena** when creating a new deployment and fill in
 the required fields:
 
 <Screenshot
@@ -65,7 +60,9 @@ if [dedicated infrastructure][ref-dedicated-infra] is used. Check out the
 | `CUBEJS_AWS_ATHENA_WORKGROUP`   | The name of the workgroup in which the query is being started                                                          | [A valid Athena Workgroup][aws-athena-workgroup] |    ❌    |
 | `CUBEJS_AWS_ATHENA_CATALOG`     | The name of the catalog to use by default                                                                              | [A valid Athena Catalog name][awsdatacatalog]    |    ❌    |
 | `CUBEJS_DB_SCHEMA`              | The name of the schema to use as `information_schema` filter. Reduces count of tables loaded during schema generation. | A valid schema name                              |    ❌    |
-| `CUBEJS_CONCURRENCY`            | The number of concurrent connections each queue has to the database. Default is `5`                                    | A valid number                                   |    ❌    |
+| `CUBEJS_CONCURRENCY` | The number of [concurrent queries][ref-data-source-concurrency] to the data source | A valid number |    ❌    |
+
+[ref-data-source-concurrency]: /product/configuration/concurrency#data-source-concurrency
 
 ## Pre-Aggregation Feature Support
 
@@ -151,4 +148,4 @@ connections are made over HTTPS.
 [ref-caching-using-preaggs-build-strats]:
   /product/caching/using-pre-aggregations#pre-aggregation-build-strategies
 [ref-schema-ref-types-formats-countdistinctapprox]: /reference/data-model/types-and-formats#count_distinct_approx
-[self-preaggs-batching]: #batching
+[self-preaggs-batching]: #batching

docs/pages/product/configuration/data-sources/aws-redshift.mdx

@@ -70,9 +70,11 @@ if [dedicated infrastructure][ref-dedicated-infra] is used. Check out the
 | `CUBEJS_DB_USER`                       | The username used to connect to the database                                        | A valid database username |    ✅    |
 | `CUBEJS_DB_PASS`                       | The password used to connect to the database                                        | A valid database password |    ✅    |
 | `CUBEJS_DB_SSL`                        | If `true`, enables SSL encryption for database connections from Cube                | `true`, `false`           |    ❌    |
-| `CUBEJS_CONCURRENCY`                   | The number of concurrent connections each queue has to the database. Default is `4` | A valid number            |    ❌    |
 | `CUBEJS_DB_MAX_POOL`                   | The maximum number of concurrent database connections to pool. Default is `16`      | A valid number            |    ❌    |
 | `CUBEJS_DB_EXPORT_BUCKET_REDSHIFT_ARN` |                                                                                     |                           |    ❌    |
+| `CUBEJS_CONCURRENCY` | The number of [concurrent queries][ref-data-source-concurrency] to the data source | A valid number |    ❌    |
+
+[ref-data-source-concurrency]: /product/configuration/concurrency#data-source-concurrency
 
 ## Pre-Aggregation Feature Support
 

docs/pages/product/configuration/data-sources/clickhouse.mdx

@@ -39,8 +39,10 @@ CUBEJS_DB_PASS=**********
 | `CUBEJS_DB_USER`                | The username used to connect to the database                                        | A valid database username |    ✅    |
 | `CUBEJS_DB_PASS`                | The password used to connect to the database                                        | A valid database password |    ✅    |
 | `CUBEJS_DB_CLICKHOUSE_READONLY` | Whether the ClickHouse user has read-only access or not                             | `true`, `false`           |    ❌    |
-| `CUBEJS_CONCURRENCY`            | The number of concurrent connections each queue has to the database. Default is `5` | A valid number            |    ❌    |
 | `CUBEJS_DB_MAX_POOL`            | The maximum number of concurrent database connections to pool. Default is `20`      | A valid number            |    ❌    |
+| `CUBEJS_CONCURRENCY` | The number of [concurrent queries][ref-data-source-concurrency] to the data source | A valid number |    ❌    |
+
+[ref-data-source-concurrency]: /product/configuration/concurrency#data-source-concurrency
 
 ## Pre-Aggregation Feature Support
 

docs/pages/product/configuration/data-sources/databricks-jdbc.mdx

@@ -60,8 +60,10 @@ docker run -it -p 4000:4000 --env-file=.env cube-jdk
 | `CUBEJS_DB_DATABRICKS_TOKEN`         | The [personal access token][databricks-docs-pat] used to authenticate the Databricks connection | A valid token         |    ✅    |
 | `CUBEJS_DB_DATABRICKS_CATALOG`       | The name of the [Databricks catalog][databricks-catalog] to connect to                                                | A valid catalog name  |    ❌    |
 | `CUBEJS_DB_EXPORT_BUCKET_MOUNT_DIR`  | The path for the [Databricks DBFS mount][databricks-docs-dbfs] (Not needed if using Unity Catalog connection)         | A valid mount path    |    ❌    |
-| `CUBEJS_CONCURRENCY`                 | The number of concurrent connections each queue has to the database. Default is `2`             | A valid number        |    ❌    |
 | `CUBEJS_DB_MAX_POOL`                 | The maximum number of concurrent database connections to pool. Default is `8`                   | A valid number        |    ❌    |
+| `CUBEJS_CONCURRENCY` | The number of [concurrent queries][ref-data-source-concurrency] to the data source | A valid number |    ❌    |
+
+[ref-data-source-concurrency]: /product/configuration/concurrency#data-source-concurrency
 
 ## Pre-Aggregation Feature Support