Fast, Reliable and Efficient Monetary General Ledger

Eelaa is a fast, reliable and efficient monetary general ledger that is able to handle one million transactions per second. It can be used as a GL module of a core banking platform or as wallet infrastructure.

Features included:

• Includes two types of ledgers, both are crash-safe and ACID compliant
  • Fast: WAL-based, NTP-dependent and very fast GL able to handle a million of transactions per second.
  • Default: Fast and safe memory mapped GL able to handle 500K transactions per second.
• Multiple independent ledger instances in a single eelaa process
• Single and batch transactions processing
• Atomic (all or none) batch transactions processing
• Automatic recovery mechanism
• Source-destination accounting
• Real-time balances
• Idempotent services
• Replay attack protection
• TLS v1.3

Engineered around the best practices of designing high performance systems, like:

• Custom frame-based binary protocol
• Asynchronous and event driven TCP network stack using native transports with a batch-aware network protocol/triggers
• Custom, efficient and very fast micro HTTP server based on pure netty
• Custom atomic and crash-safe WAL implementation
• FFM and off-heap memory management to decrease GC pressure
• Fast compression mechanism
• Having mechanical sympathy for the hardware it’s running on (lock-free implementations)
• Used native libraries where ever possible

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Clustering & Replication

Eelaa focuses on being a fast, single-node ledger engine. High availability and storage replication are intentionally delegated to mature infrastructure such as DRBD instead of implementing distributed consensus within the server.

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REST APIs

Documentation can be found at REST APIs Documentation.

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Binary Protocol Specification

Documentation in progress.

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Test & Development Setup (macOS)

• JDK 27
  • curl -s "https://get.sdkman.io" | bash
  • sdk install java 27.0.0-oracle
• LZ4 Compression Library
  • /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
  • brew install lz4
• LMDB
  • brew install lmdb

Then after, set the following environment variable:

export LIBRARIES_NATIVE_LZ4_PATH="/the/path/to/liblz4.dylib"

export LIBRARIES_NATIVE_LMDB_PATH="/the/path/to/liblmdb.dylib"

For example:

export LIBRARIES_NATIVE_LZ4_PATH="/opt/homebrew/Cellar/lz4/1.10.0/lib/liblz4.dylib"

export LIBRARIES_NATIVE_LMDB_PATH="/opt/homebrew/Cellar/lmdb/0.9.35/lib/liblmdb.dylib"

At final step run:

./scripts/test.sh

You are now ready to import the project into your IDE to test/develop further.

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Dockerize Project

To dockerize the project you need docker engine or docker desktop to be installed; See https://www.docker.com to follow the installation instructions.

Then after, run:

./scripts/dockerize.sh

The Dockerfile also includes installation steps for both required native libraries.