Table of Contents generated with DocToc
- Overview
- Quick Start
- Command Line
- Testing
- Configuration
- Development
- Failover
- SDK
- Examples
- Contact Us
ChainStorage is the foundational component of ChainNode and Chainsformer. These projects represent the crypto data processing suites (code name ChainStack) widely adopted within Coinbase.
ChainStorage is inspired by the Change Data Capture paradigm, commonly used in the big data world. It continuously replicates the changes (i.e. new blocks) on the blockchain, and acts like a distributed file system for the blockchain.
It aims to provide an efficient and flexible way to access the on-chain data:
- Efficiency is optimized by storing data in horizontally-scalable storage with a key-value schema. At Coinbase's production environment, ChainStorage can serve up to 1,500 blocks per second, enabling teams to build various indexers cost-effectively.
- Flexibility is improved by decoupling data interpretation from data ingestion. ChainStorage stores the raw data, and the parsing is deferred until the data is consumed. The parsers are shipped as part of the SDK and run on the consumer side. Thanks to the ELT (Extract, Load, Transform) architecture, we can quickly iterate on the parser without ingesting the data from the blockchain again.
This section will guide you through setting up ChainStorage on your local machine for development.
- Go (version 1.22):
Verify your Go installation:
brew install go@1.22 brew unlink go brew link go@1.22
go version
- Protocol Buffer Compiler (protobuf): Used for code generation based on
.protofiles.Verify your installation:brew install protobuf@29 brew unlink protobuf brew link protobuf@29
protoc --version
This command (run only once) installs necessary Go tools for development, like linters and code generators.
make bootstrapThis command compiles the ChainStorage Go programs.
make buildYou'll run this command whenever you make changes to the Go source code.
ChainStorage uses Protocol Buffers to define data structures. This command generates Go code from those definitions.
make protoYou'll need to run this if you change any .proto files (usually located in the protos/ directory).
the cmd/admin tool consists of multiple sub command.
admin is a utility for managing chainstorage
Usage:
admin [command]
Available Commands:
backfill Backfill a block
block Fetch a block
completion Generate the autocompletion script for the specified shell
event tool for managing events storage
help Help about any command
sdk
validator
workflow tool for managing chainstorage workflows
Flags:
--blockchain string blockchain full name (e.g. ethereum)
--env string one of [local, development, production]
-h, --help help for admin
--meta output metadata only
--network string network name (e.g. mainnet)
--out string output filepath: default format is json; use a .pb extension for protobuf format
--parser string parser type: one of native, mesh, or raw (default "native")
Use "admin [command] --help" for more information about a command.
All sub-commands require the blockchain, env, network flags.
This command allows you to fetch and inspect individual blocks from a specified blockchain and network.
Usage Example:
Fetch block #46147 from Ethereum mainnet, using your local configuration:
go run ./cmd/admin/main.go block --blockchain ethereum --network mainnet --env local --height 46147block: The command to fetch block data.--blockchain ethereum --network mainnet --env local: These flags specify the target (Ethereum mainnet) and the configuration environment (local).--height 46147: The specific block number you want to retrieve.
You can also fetch blocks from other supported blockchains and networks by changing the flag values:
Fetch a block from Ethereum Goerli testnet:
# Assuming Goerli is configured and data is available
go run ./cmd/admin/main.go block --blockchain ethereum --network goerli --env local --height 12345Backfill a block from BSC mainnet:
go run ./cmd/admin backfill --blockchain bsc --network mainnet --env development --start-height 10408613 --end-height 10408614
Stream block events from a specific event sequence id:
go run ./cmd/admin sdk stream --blockchain ethereum --network mainnet --env development --sequence 2228575 --event-tag 1# Run everything
make test
# Run the blockchain package only
make test TARGET=internal/blockchain/...# Run everything
make integration
# Run the storage package only
make integration TARGET=internal/storage/...
# If test class implemented with test suite, add suite name before the test name
make integration TARGET=internal/blockchain/... TEST_FILTER=TestIntegrationPolygonTestSuite/TestPolygonGetBlockBefore running the functional test, you need to provide the endpoint group config by creating secrets.yml.
See here for more details.
# Run everything
make functional
# Run the workflow package only
make functional TARGET=internal/workflow/...
# Run TestIntegrationEthereumGetBlock only
make functional TARGET=internal/blockchain/... TEST_FILTER='TestIntegrationEthereumGetBlock$$'
# If test class implemented with test suite, add suite name before the test name
make functional TARGET=internal/blockchain/... TEST_FILTER=TestIntegrationPolygonTestSuite/TestPolygonGetBlockConfiguration in ChainStorage tells the system:
- Which blockchain to connect to (like Ethereum, Bitcoin, etc.)
- How to connect to that blockchain (which nodes/servers to use)
- Where to store the data it collects
- How to process and manage the data
To understand the structure and elements of ChainStorage's config, it's important to comprehend its dependencies.
ChainStorage needs several services to work properly:
-
Blockchain Nodes: These are servers that maintain a copy of the blockchain. ChainStorage connects to these to get blockchain data.
- Example: An Ethereum node that provides information about Ethereum transactions and blocks
-
Storage Systems:
- Blob storage - current implementation is on AWS S3, and the local service is provied by localstack
- Key value storage - current implemnentation is based on dynamodb and the local service is provied by localstack
- Dead Letter queue - current implementation is on SQS and the local service is provied by localstack
-
Workflow Engine (Temporal):Temporal is a workflow engine that orchestrates the data ingestion workflow. It calls ChainStorage service endpoint to complete various of tasks.
The config template directory is in config_templates/config, which make config reads this directory and generates the config into the config/chainstorage directory.
Every new asset in ChainStorage consists of ChainStorage configuration files.
These configuration files are generated from .template.yml template files using:
make configthese templates will be under a directory dedicated to storing the config templates
in a structure that mirrors the final config structure of the config
directories. All configurations from this directory will be generated within the final
respective config directories
ChainStorage depends on the following environment variables to resolve the path of the configuration.
The directory structure is as follows: config/{namespace}/{blockchain}/{network}/{environment}.yml.
CHAINSTORAGE_NAMESPACE: A{namespace}is logical grouping of several services, each of which manages its own blockchain and network. The default namespace is chainstorage. To deploy a different namespace, set the env var to the name of a subdirectory of ./config.CHAINSTORAGE_CONFIG: This env var, in the format of{blockchain}-{network}, determines the blockchain and network managed by the service. The naming is defined in c3/common.CHAINSTORAGE_ENVIRONMENT: This env var controls the{environment}in which the service is deployed. Possible values includeproduction,development, andlocal(which is also the default value).
Configuration templates are composable and inherit configuration properties from
"parent templates", which can be defined in base.template.yml, local.template.yml, development.template.yml,
and production.template.yml.
These parent templates are merged into the final blockchain and network specific base.template.yml,
local.template.yml, development.template.yml, production.template.yml configurations respectively.
In the following example, config/chainstorage/ethereum/mainnet/base.yml
inherits from config_templates/base.template.yml and config_templates/chainstorage/ethereum/mainnet/base.template.yml,
with the latter taking precedence over the former.
config
chainstorage
ethereum
mainnet
base.yml
development.yml
local.yml
production.yml
config_templates
chainstorage
ethereum
mainnet
base.template.yml
development.template.yml
local.template.yml
production.template.yml
base.template.yml
development.template.yml
local.template.yml
production.template.yml
The template language supports string substitution for the Config-Name and Environment using the {{, }} tags.
Example:
foo: {{blockchain}}-{{network}}-{{environment}}The blockchain, {{blockchain}}, network, {{network}}, and environment, {{environment}} template variables
are derived from the directory and file naming schemes associated with cloud and ChainStorage configurations.
Endpoint group is an abstraction for one or more JSON-RPC endpoints.
EndpointProvider uses the endpoint_group config to implement
client-side routing to the node provider.
ChainStorage utilizes two endpoint groups to speed up data ingestion:
- master: This endpoint group is used to resolve the canonical chain and determine what blocks to ingest next. Typically, sticky session is turned on for this group to ensure stronger data consistency between the requests.
- slave: This endpoint group is used to ingest the data from the blockchain. During data ingestion, the new blocks are ingested in parallel and out of order. Typically, the endpoints are selected in a round-robin fashion, but you may increase the weights to send more traffic to certain endpoints.
If your node provider, e.g. QuickNode, already has built-in load balancing, your endpoint group may contain only one endpoint, as illustrated by the following configuration:
chain:
client:
master:
endpoint_group: |
{
"endpoints": [
{
"name": "quicknode-foo-bar-sticky",
"url": "https://foo-bar.matic.quiknode.pro/****",
"weight": 1
}
],
"sticky_session": {
"header_hash": "x-session-hash"
}
}
slave:
endpoint_group: |
{
"endpoints": [
{
"name": "quicknode-foo-bar-round-robin",
"url": "https://foo-bar.matic.quiknode.pro/****",
"weight": 1
}
]
}You can override configurations in two ways:
- Environment Variables: You may override any configuration using an environment variable. The environment variable should be prefixed with "CHAINSTORAGE_". For nested dictionary, use underscore to separate the keys.
For example, you may override the endpoint group config at runtime by injecting the following environment variables:
- master: CHAINSTORAGE_CHAIN_CLIENT_MASTER_ENDPOINT_GROUP
- slave: CHAINSTORAGE_CHAIN_CLIENT_SLAVE_ENDPOINT_GROUP
Security Best Practice - PostgreSQL Credentials: For sensitive data like database passwords, always use environment variables instead of hardcoding them in config files:
# PostgreSQL credentials (never put these in config files!)
export CHAINSTORAGE_AWS_POSTGRES_USER="your_username"
export CHAINSTORAGE_AWS_POSTGRES_PASSWORD="your_secure_password"
# Storage type configuration
export CHAINSTORAGE_STORAGE_TYPE_META="POSTGRES"- secrets.yml: Alternatively, you may override the configuration by creating
secrets.ymlwithin the same directory. Its attributes will be merged into the runtime configuration and take the highest precedence. Note that this file may contain credentials and is excluded from check-in by.gitignore.
Example config/chainstorage/ethereum/mainnet/.secrets.yml:
storage_type:
meta: POSTGRES
aws:
postgres:
user: your_username
password: your_secure_passwordStart the dockers by the docker-compose file from project root folder:
make localstackIf you have developed ChainStorage before locally with previous docker compose file and got below error message
nc: bad address 'postgresql'Please remove existing ChainStorage container and reran
make localstack
The next step is to start the server locally:
# Ethereum Mainnet
# Use aws local stack
make server
# If want to start testnet (goerli) server
# Use aws local stack
make server CHAINSTORAGE_CONFIG=ethereum_goerliChainStorage supports PostgreSQL as an alternative to DynamoDB for metadata storage. Here's how to set it up:
You can use Docker to run PostgreSQL locally:
# Start PostgreSQL container
docker run --name chainstorage-postgres \
-e POSTGRES_USER=temporal \
-e POSTGRES_PASSWORD=temporal \
-e POSTGRES_DB=postgres \
-p 5432:5432 \
-d postgres:13Or add it to your existing docker-compose setup.
Create or modify your local config to use PostgreSQL instead of DynamoDB. You have two options:
Option A: Create a local secrets file (recommended for development)
Create config/chainstorage/{blockchain}/{network}/.secrets.yml (e.g., config/chainstorage/ethereum/mainnet/.secrets.yml):
storage_type:
meta: POSTGRESOption B: Set via environment variable
export CHAINSTORAGE_STORAGE_TYPE_META=POSTGRESSince PostgreSQL credentials should not be hardcoded in config files, set them via environment variables:
# PostgreSQL connection details
export CHAINSTORAGE_AWS_POSTGRES_USER="temporal"
export CHAINSTORAGE_AWS_POSTGRES_PASSWORD="temporal"
export CHAINSTORAGE_AWS_POSTGRES_HOST="localhost"
export CHAINSTORAGE_AWS_POSTGRES_PORT="5432"
export CHAINSTORAGE_AWS_POSTGRES_SSL_MODE="require"Now start the server with PostgreSQL configuration:
# Method 1: Using exported environment variables
make server
# Method 2: Setting environment variables inline
CHAINSTORAGE_STORAGE_TYPE_META=POSTGRES \
CHAINSTORAGE_AWS_POSTGRES_USER="temporal" \
CHAINSTORAGE_AWS_POSTGRES_PASSWORD="temporal" \
make serverThe following environment variables can be used to configure PostgreSQL:
| Environment Variable | Config Path | Description | Default |
|---|---|---|---|
CHAINSTORAGE_AWS_POSTGRES_HOST |
aws.postgres.host |
PostgreSQL hostname | localhost |
CHAINSTORAGE_AWS_POSTGRES_PORT |
aws.postgres.port |
PostgreSQL port | 5432 |
CHAINSTORAGE_AWS_POSTGRES_USER |
aws.postgres.user |
PostgreSQL username | (required) |
CHAINSTORAGE_AWS_POSTGRES_PASSWORD |
aws.postgres.password |
PostgreSQL password | (required) |
CHAINSTORAGE_AWS_POSTGRES_DATABASE |
aws.postgres.database |
Database name | chainstorage_{blockchain}_{network} |
CHAINSTORAGE_AWS_POSTGRES_SSL_MODE |
aws.postgres.ssl_mode |
SSL mode | require |
CHAINSTORAGE_AWS_POSTGRES_MAX_CONNECTIONS |
aws.postgres.max_connections |
Maximum connection pool size | 25 |
CHAINSTORAGE_AWS_POSTGRES_MIN_CONNECTIONS |
aws.postgres.min_connections |
Minimum connection pool size | 5 |
CHAINSTORAGE_AWS_POSTGRES_CONNECT_TIMEOUT |
aws.postgres.connect_timeout |
Connection establishment timeout | 30s |
CHAINSTORAGE_AWS_POSTGRES_STATEMENT_TIMEOUT |
aws.postgres.statement_timeout |
Statement/transaction timeout | 60s |
CHAINSTORAGE_STORAGE_TYPE_META |
storage_type.meta |
Meta storage type | DYNAMODB |
ChainStorage will automatically create the necessary database schema and run migrations when it starts up. The database will contain tables for:
block_metadata- Block metadata and headerscanonical_blocks- Canonical chain stateblock_events- Blockchain event log
ChainStorage supports PostgreSQL as an alternative to DynamoDB for metadata storage with role-based access for enhanced security.
Quick Start:
# Start PostgreSQL with automatic database initialization
docker-compose -f docker-compose-local-dev.yml up -d chainstorage-postgresThis automatically creates:
- Shared
chainstorage_workerandchainstorage_serverroles - Databases for all supported networks (ethereum_mainnet, bitcoin_mainnet, etc.)
- Proper permissions (worker: read-write, server: read-only)
Default Credentials:
- Worker:
chainstorage_worker/worker_password - Server:
chainstorage_server/server_password
Manual Setup:
chainstorage admin setup-postgres \
--blockchain ethereum \
--network mainnet \
--env local \
--master-user postgres \
--master-password postgres \
--worker-password worker_password \
--server-password server_passwordIn production, databases are initialized using the db-init command:
# Connect to admin pod
kubectl exec -it deploy/chainstorage-admin-dev-console -c chainstorage-admin -- /bin/bash
# Initialize database for ethereum-mainnet
./admin db-init --blockchain ethereum --network mainnet --env devThe db-init command:
- Reads master credentials from environment variables (injected by Kubernetes)
- Fetches network-specific credentials from AWS Secrets Manager (
chainstorage/db-creds/{env}) - Creates the database (e.g.,
chainstorage_ethereum_mainnet) - Creates network-specific users with passwords from the secret
- Grants appropriate permissions
Databases follow the pattern: chainstorage_{blockchain}_{network}
Examples:
chainstorage_ethereum_mainnetchainstorage_bitcoin_mainnetchainstorage_polygon_testnet
Note: Hyphens in blockchain/network names are replaced with underscores.
Start the full local development stack:
# Start all services (PostgreSQL, Temporal, LocalStack)
make localstack
# Load environment variables
source scripts/postgres-roles-local.envDatabase Operations:
# Set up PostgreSQL database and roles for a new network
go run ./cmd/admin setup-postgres \
--blockchain ethereum \
--network mainnet \
--env local \
--master-user postgres \
--master-password postgres \
--host localhost \
--port 5433
# Initialize databases from AWS Secrets Manager (production)
go run ./cmd/admin db-init \
--secret-name chainstorage/db-init/prod \
--aws-region us-east-1
# Migrate data from DynamoDB to PostgreSQL
chainstorage admin migrate-dynamodb-to-postgres \
--blockchain ethereum \
--network mainnet \
--env local \
--start-height 1000000 \
--end-height 1001000| Command | Description | Example |
|---|---|---|
setup-postgres |
Create database and roles | setup-postgres --master-user postgres --master-password postgres |
db-init |
Initialize from AWS Secrets Manager | db-init --blockchain ethereum --network mainnet --env dev |
migrate-dynamodb-to-postgres |
Migrate data from DynamoDB to PostgreSQL | migrate-dynamodb-to-postgres --start-height 1000000 --end-height 1001000 |
Check S3 files:
You can checkout the config from config/chainstorage/{{Blockchain}}/{{network}}/{{evironment}} for the value of S3 bucket name, dynamoDB tables, and SQS name.
aws s3 --no-sign-request --region local --endpoint-url http://localhost:4566 ls --recursive example-chainstorage-ethereum-mainnet-dev/Check DynamoDB rows:
aws dynamodb --no-sign-request --region local --endpoint-url http://localhost:4566 scan --table-name example_chainstorage_blocks_ethereum_mainnetCheck DLQ:
aws sqs --no-sign-request --region local --endpoint-url http://localhost:4566/000000000000/example_chainstorage_blocks_ethereum_mainnet_dlq receive-message --queue-url "http://localhost:4566/000000000000/example_chainstorage_blocks_ethereum_mainnet_dlq" --max-number-of-messages 10 --visibility-timeout 2Open Temporal UI in a browser by entering the URL: http://localhost:8080/namespaces/chainstorage-ethereum-mainnet/workflows
Start the backfill workflow:
go run ./cmd/admin workflow start --workflow backfiller --input '{"StartHeight": 11000000, "EndHeight": 11000100, "NumConcurrentExtractors": 24}' --blockchain ethereum --network mainnet --env localStart the benchmarker workflow:
go run ./cmd/admin workflow start --workflow benchmarker --input '{"StartHeight": 1, "EndHeight": 12000000, "NumConcurrentExtractors": 24, "StepSize":1000000, "SamplesToTest":500}' --blockchain ethereum --network mainnet --env localStart the monitor workflow:
go run ./cmd/admin workflow start --workflow monitor --blockchain ethereum --network mainnet --env local --input '{"StartHeight": 11000000}'Start the poller workflow:
go run ./cmd/admin workflow start --workflow poller --input '{"Tag": 0, "MaxBlocksToSync": 100, "Parallelism":4}' --blockchain ethereum --network mainnet --env localNOTE: the recommended value for "parallelism" depend on the capacity of your node provider. If you are not sure what value should be used, just drop it from the command.
Start the streamer workflow:
go run ./cmd/admin workflow start --workflow streamer --input '{}' --blockchain ethereum --network goerli --env localStart the migrator workflow (event-driven migration from DynamoDB to PostgreSQL):
# Migrate events by sequence range
go run ./cmd/admin workflow start --workflow migrator --input '{"StartEventSequence": 1, "EndEventSequence": 1000, "Tag": 2, "EventTag": 3, "BatchSize": 500, "Parallelism": 2, "CheckpointSize": 10000}' --blockchain ethereum --network mainnet --env local
# Auto-resume from last migrated position
go run ./cmd/admin workflow start --workflow migrator --input '{"StartEventSequence": 0, "EndEventSequence": 100000, "Tag": 2, "EventTag": 3, "AutoResume": true}' --blockchain ethereum --network mainnet --env local
# Continuous sync mode with auto-resume
go run ./cmd/admin workflow start --workflow migrator --input '{"StartEventSequence": 0, "EndEventSequence": 0, "Tag": 2, "EventTag": 3, "AutoResume": true, "ContinuousSync": true, "BatchSize": 500,"Parallelism": 2, "CheckpointSize": 10000}' --blockchain ethereum --network mainnet --env local
# Custom batch size and parallelism for large migrations
go run ./cmd/admin workflow start --workflow migrator --input '{"StartEventSequence": 1000000, "EndEventSequence": 2000000, "Tag": 1, "EventTag": 0, "BatchSize": 10000, "Parallelism": 16, "CheckpointSize": 100000}' --blockchain ethereum --network mainnet --env localNote: The migrator uses an event-driven architecture where events are fetched by sequence number and blocks are extracted from BLOCK_ADDED events. This ensures data consistency and proper handling of blockchain reorganizations.
Start the cross validator workflow:
go run ./cmd/admin workflow start --workflow cross_validator --input '{"StartHeight": 15500000, "Tag": 0}' --blockchain ethereum --network mainnet --env localStart the event backfiller workflow:
go run ./cmd/admin workflow start --workflow event_backfiller --input '{"Tag": 0, "EventTag": 0, "StartSequence": 1000, "EndSequence": 2000}' --blockchain ethereum --network mainnet --env localStart the replicator workflow:
go run ./cmd/admin workflow start --workflow replicator --input '{"Tag": 0, "StartHeight": 1000000, "EndHeight": 1001000}' --blockchain ethereum --network mainnet --env localStop the monitor workflow:
go run ./cmd/admin workflow stop --workflow monitor --blockchain ethereum --network mainnet --env localStop a versioned streamer workflow:
go run ./cmd/admin workflow stop --workflow streamer --blockchain ethereum --network mainnet --env local --workflowID {workflowID}Using Temporal CLI to check the status of the workflow:
brew install tctl
tctl --address localhost:7233 --namespace chainstorage-ethereum-mainnet workflow show --workflow_id workflow.backfillerChainStorage supports nodes failover feature to mitigate the issue from nodes which may impact our SLA. When primary clusters are down, we can choose to switch over to failover clusters to mitigate incidents, instead of waiting for nodes get fully recovered.
Check this comment to get more details of the primary/secondary cluster definition.
To check if failover clusters are provided, please go to config service and check the endpoints configurations.
Both Backfiller and Poller workflows provide failover feature without updating configs in the config service which requires approvals as well as redeployment.
To use failover clusters for those two workflows, you simply need to set the Failover workflow param as true when you trigger it.
Note: By default, the Failover workflow param should be set as false, which means the primary clusters should always be first choice.
If you intend to use failover clusters, please update endpoints configs in config service instead.
Poller workflow provides an automatic failover mechanism so that we don't need to manually restart workflows with Failover param.
This feature is guarded by the failover_enabled configuration.
Once this feature is enabled, when the workflow execution using primary clusters fails, it will automatically trigger a new workflow run with Failover=true.
Implementation Code.
Install tctl, it is a command-line tool that you can use to interact with a Temporal cluster. More info can be found here: https://docs.temporal.io/tctl/
brew install tctl# local
grpcurl --plaintext localhost:9090 coinbase.chainstorage.ChainStorage/GetLatestBlock
grpcurl --plaintext -d '{"start_height": 0, "end_height": 10}' localhost:9090 coinbase.chainstorage.ChainStorage/GetBlockFilesByRange
grpcurl --plaintext -d '{"sequence_num": 2223387}' localhost:9090 coinbase.chainstorage.ChainStorage/StreamChainEvents
grpcurl --plaintext -d '{"initial_position_in_stream": "EARLIEST"}' localhost:9090 coinbase.chainstorage.ChainStorage/StreamChainEvents
grpcurl --plaintext -d '{"initial_position_in_stream": "LATEST"}' localhost:9090 coinbase.chainstorage.ChainStorage/StreamChainEvents
grpcurl --plaintext -d '{"initial_position_in_stream": "13222054"}' localhost:9090 coinbase.chainstorage.ChainStorage/StreamChainEventsChainstorage also provides SDK, and you can find supported methods here
Note:
-
GetBlocksByRangeWithTagis not equivalent to the batch version ofGetBlockWithTagsince you don't have a way to specify the block hash. So when you useGetBlocksByRangeWithTagand if it goes beyond the current tip of chain due to reorg, you'll get back theFailedPreconditionerror because it exceeds the latest watermark.In conclusion, it's safe to use
GetBlocksByRangeWithTagfor backfilling since the reorg will not happen for past blocks, however, you'd be suggested to useGetBlockWithTagfor recent blocks (e.g. streaming case).
Below are several patterns you can choose for data processing.
-
If you want the most up-to-date blocks, you need to use the streaming APIs to handle the chain reorg events:
-
Unified batch and streaming: - Download, let's say 10k events, using
GetChainEvents. - Break down 10k events into small batches, e.g. 20 events/batch. - Process those batches in parallel. - For events in each batch, it can be processed either sequentially or in parallel usingGetBlockWithTag. - Update watermark once all small batches have been processed. - Repeat above steps.With the above pattern, you can unify batch and streaming use cases. When your data pipeline is close to the tip,
GetChainEventswill simply return all available blocks. -
Separate workflows for backfilling and live streaming: Use
GetBlocksByRangeWithTagfor backfilling and then switch over toStreamChainEventsfor live streaming. -
If you don't want to deal with chain reorg, you may use the batch APIs as follows:
- Maintain a distance (
irreversibleDistance) to the tip, the irreversible distance can be queried usingGetChainMetadata. - Get the latest block height (
latest) usingGetLatestBlock. - Poll for new data from current watermark block to the block (
latest - irreversibleDistance) usingGetBlocksByRangeWithTag. - Repeat above steps periodically.
See below for a few examples for implementing a simple indexer using the SDK. Note that the examples are provided in increasing complexity.
In this example, we use the blocks API to fetch the confirmed blocks as follows:
- Fetch the maximum reorg distance (
irreversibleDistance). - Fetch the latest block height (
latest). - Poll for new blocks from the checkpoint up to the latest confirmed block (
latest - irreversibleDistance). usingGetBlocksByRange. - Update the checkpoint.
- Repeat above steps periodically.
This example demonstrates how to stream the latest blocks and handle chain reorgs.
The worker processes the events sequentially and relies on BlockchainEvent_Type
to construct the canonical chain.
For example, given +1, +2, +3, -3, -2, +2', +3' as the events, the canonical chain would be +1, +2', +3'.
The last example showcases how to turn the data processing into an embarrassingly parallel problem by leveraging the mono-increasing sequence number. In this example, though the events are processed in parallel and out of order, the logical ordering guarantee is preserved.
- Download, say 10k events, using
GetChainEvents. Note that this API is non-blocking, and it returns all the available events if the requested amount is not available. This enables us to unify batch and stream processing. - Break down 10k events into small batches, e.g. 20 events/batch.
- Distribute those batches to a number of workers for parallel processing. Note that this step is not part of the example.
- For events in each batch, it can be processed either sequentially or in parallel using
GetBlockWithTag. - Implement versioning using the mono-increasing sequence numbers provided by the events. See here for more details.
- Update watermark once all the batches have been processed.
- Repeat above steps.
Tool to migrate blockchain data from DynamoDB to PostgreSQL with complete reorg support and data integrity preservation.
The migration tool performs a comprehensive transfer of blockchain data:
- Block metadata from DynamoDB to PostgreSQL (
block_metadata+canonical_blockstables) - Events from DynamoDB to PostgreSQL (
block_eventstable) - Complete reorg data including both canonical and non-canonical blocks
- Event ID-based migration for efficient sequential processing
Critical Requirements:
- Block metadata must be migrated before events (foreign key dependencies)
- Migration preserves complete blockchain history including all reorg blocks
- Canonical block identification is maintained through migration ordering
# Migrate both blocks and events for a height range
go run cmd/admin/*.go migrate \
--env=local \
--blockchain=ethereum \
--network=mainnet \
--start-height=1000000 \
--end-height=1001000 \
--tag=1 \
--event-tag=0We have set up a Discord server soon. Here is the link to join (limited 10) https://discord.com/channels/1079683467018764328/1079683467786334220.