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Running SubQuery Locally

SubQuery TeamAbout 5 min

Running SubQuery Locally

This guide works through how to run a local SubQuery node on your infrastructure, which includes both the indexer and query service. Don't want to worry about running your own SubQuery infrastructure? SubQuery provides a Managed Serviceopen in new window to the community for free. Follow our publishing guide to see how you can upload your project to SubQuery Managed Serviceopen in new window.

There are two ways to run a project locally, using Docker or running the individual components using NodeJS (indexer node service and query service).

Location is everything

Run the services geographically close to one another and where you think most requests will come from. Running the node or query service far away from the DB will massively decrease performance.

Using Docker

An alternative solution is to run a Docker Container, defined by the docker-compose.yml file. For a new project that has been just initialised you won't need to change anything here.

Under the project directory run the following command:

docker-compose pull && docker-compose up


It may take some time to download the required packages (@subql/nodeopen in new window, @subql/queryopen in new window, and Postgres) for the first time but soon you'll see a running SubQuery node.

Running an Indexer (subql/node)


A SubQuery node is an implementation that extracts Substrate/Polkadot-based blockchain data per the SubQuery project and saves it into a Postgres database.

If you are running your project locally using subql-node or subql-node-<network>, make sure you enable the pg_extension btree_gist

You can run the following SQL query:



npm install -g @subql/node


Please note that we DO NOT encourage the use of yarn global due to its poor dependency management which may lead to an error down the line.

Once installed, you can start a node with the following command:

subql-node <command>

Key Commands

The following commands will assist you to complete the configuration of a SubQuery node and begin indexing. To find out more, you can always run --help.

Point to local project path

subql-node -f your-project-path

Connect to database

export DB_USER=postgres
export DB_PASS=postgres
export DB_DATABASE=postgres
export DB_HOST=localhost
export DB_PORT=5432
subql-node -f your-project-path

Depending on the configuration of your Postgres database (e.g. a different database password), please ensure also that both the indexer (subql/node) and the query service (subql/query) can establish a connection to it.

If your database is using SSL, you can use the following command to add the server certificate to it:

subql-node -f your-project-path --pg-ca /path/to/ca.pem

If your database is using SSL and requires a client certificate, you can use the following command to connect to it:

subql-node -f your-project-path --pg-ca /path/to/ca.pem --pg-cert /path/to/client-cert.pem --pg-key /path/to/client-key.key

Specify a configuration file

subql-node -c your-project-config.yml

This will point the query node to a manifest file which can be in TS, YAML or JSON format.

Change the block fetching batch size

subql-node -f your-project-path --batch-size 200

<BlockDispatcherService> INFO Enqueueing blocks 203...402, total 200 blocks
<BlockDispatcherService> INFO Enqueueing blocks 403...602, total 200 blocks

When the indexer first indexes the chain, fetching single blocks will significantly decrease the performance. Increasing the batch size to adjust the number of blocks fetched will decrease the overall processing time. The current default batch size is 100.


SubQuery uses Node.js, by default this will use 4GB of memory. If you are running into memory issues or wish to get the most performance out of indexing you can increase the memory that will be used by setting the following environment variable export NODE_OPTIONS=--max_old_space_size=<memory-in-MB>. It's best to make sure this only applies to the node and not the query service.

Monitoring Indexer Health

There are 2 endpoints that you can use to check and monitor the health of a running SubQuery node.

  • Health check endpoint that returns a simple 200 response.
  • Metadata endpoint that includes additional analytics of your running SubQuery node.

Append this to the base URL of your SubQuery node. Eg http://localhost:3000/meta will return:

    "currentProcessingHeight": 1000699,
    "currentProcessingTimestamp": 1631517883547,
    "targetHeight": 6807295,
    "bestHeight": 6807298,
    "indexerNodeVersion": "0.19.1",
    "lastProcessedHeight": 1000699,
    "lastProcessedTimestamp": 1631517883555,
    "uptime": 41.151789063,
    "polkadotSdkVersion": "5.4.1",
    "apiConnected": true,
    "injectedApiConnected": true,
    "usingDictionary": false,
    "chain": "Polkadot",
    "specName": "polkadot",
    "genesisHash": "0x91b171bb158e2d3848fa23a9f1c25182fb8e20313b2c1eb49219da7a70ce90c3",
    "blockTime": 6000

http://localhost:3000/health will return HTTP 200 if successful.

A 500 error will be returned if the indexer is not healthy. This can often be seen when the node is booting up.

    "status": 500,
    "error": "Indexer is not healthy"

If an incorrect URL is used, a 404 not found error will be returned.

"statusCode": 404,
"message": "Cannot GET /healthy",
"error": "Not Found"

You should also be regularly monitoring your query service health.

Debug your project

Use the node inspectoropen in new window to run the following command.

node --inspect-brk <path to subql-node> -f <path to subQuery project>

For example:

node --inspect-brk /usr/local/bin/subql-node -f ~/Code/subQuery/projects/subql-helloworld/
Debugger listening on ws://
For help, see:
Debugger attached.

Then open up the Chrome dev tools, go to Source > Filesystem and add your project to the workspace and start debugging. For more information, check out How to debug a SubQuery project.

Running a Query Service (subql/query)


npm install -g @subql/query


Please note that we DO NOT encourage the use of yarn global due to its poor dependency management which may lead to an error down the line.

Running the Query service

export DB_HOST=localhost
subql-query --name <project_name> --playground

Make sure the project name is the same as the project name when you initialise the project. Also, check the environment variables are correct.

After running the subql-query service successfully, open your browser and head to http://localhost:3000. You should see a GraphQL playground showing in the Explorer and the schema that is ready to query.


The query service will fail to start if the node has not yet created the DB schema for your project. If you are automating the startup of your project, please ensure that the node service always starts and is running healthy first - you can see an example of how we do this in the default docker-compose.yaml

Monitoring Query Service Health

Unlike the indexer node, there is no specific health check route. Instead you can make a simple GraphQL query such as getting the metadata:

curl 'http://localhost:3000' -X POST --data-raw '{"query":"{\n  _metadata {\n    chain\n    lastProcessedHeight\n    lastProcessedTimestamp\n  }\n}"}'

Recommendations for Self Hosting in a Production Environment

If you wish to self host SubQuery in a production manner there are many other things to consider. These can vary greatly depending on how you choose to run SubQuery so we while we might find it hard to support your team, we hope to point you in the right direction.

It is recommended that you are familiar with running web services in production, if this sounds like too much work we provide the SubQuery Managed Serviceopen in new window to provide all of this functionality for you.

You will want to review Running High Performance SubQuery Infrastructure.