Repository files navigation

Pelikan is a framework for developing cache services. It is:

• Fast: Pelikan provides high-throughput and low-latency caching solutions.

• Reliable: Pelikan is designed for large-scale deployment and theimplementation is informed by our operational experiences.

• Modular: Pelikan is a framework for rapidly developing new cachingsolutions by focusing on the inherent architectural similarity between cachingservices and providing reusable low-level components.

Website |Chat

• Overview
  • Products
  • Features
• Build
• Usage
• Community
  • Stay in touch
  • Contributing
• Documentation
• License

After years of using and working on various cache services, we built a commonframework that reveals the inherent architectural similarity among them.

By creating well-defined modules, most of the low-level functionalities arereused as we create different binaries. The implementation learns from ouroperational experiences to improve performance and reliability, and leads tosoftware designed for large-scale deployment.

The framework approach allows us to develop new features and protocols quickly.

Pelikan contains the following products:

• pelikan_segcache_rs: a Memcached-like server with Segcache as the backingstorage, a TTL-centric design offering extremely high memory efficiency andexcellent core scalability. See ourNSDI'21 paper for designand evaluation details.
• pelikan_pingserver_rs: an over-engineered, production-ready ping serveruseful as a tutorial and for measuring baseline RPC performance
• momento_proxy: a proxy which allows existingapplications to use Momento instead of a Memcache-compatible cache backend.

Pelikan legacy codebase in C can be found within thelegacy folder of thisproject. It offers the same design blueprint as the current mainline, andimplements multiple storage backend, data structures, and protocols. However, it onlybuilds single-threaded, plain-text backends. It remains as a reference, butis not actively worked on. We do not recommend it for production deployments.

• runtime separation of control and data plane
• predictably low latencies via lockless data structures, worker never blocks
• per-module config options and metrics that can be composed easily
• multiple storage and protocol implementations, easy to further extend
• low-overhead command logger for hotkey and other important data analysis

• Ruststable toolchain
• (to buildmomento_proxy) Followthe gRPC instructions hereto install Protocol Buffer Compiler. Alternatively, you can skip themomento_proxy package.
• C toolchain:llvm/clang (>= 7.0)
• Build tools:cmake (>= 3.2)

The C/C++ tools are used by Pelikan dependencies such as BoringSSL, and alsonecessary if you are building legacy Pelikan which is written in C.

git clone https://github.com/pelikan-io/pelikancd pelikancargo build --release# to skip momento_proxy, run:# cargo build --workspace --exclude momento_proxy --release

cargotest

Usingpelikan_segcache_rs as an example, other executables are highly similar.

To get info of the service, including usage format and options, run:

target/release/pelikan_segcache_rs --help

To launch the service with default settings, simply run:

target/release/pelikan_segcache_rs

To launch the service with the sample config file, run:

target/release/pelikan_segcache_rs config/segcache.toml

You should be able to try out the server using an existing memcached client,or simply withtelnet.

$ telnet localhost 12321Trying 127.0.0.1...Connected to localhost.Escape character is'^]'.set foo 0 0 3barSTORED

Attention: useadmin port for all non-data commands.

$ telnet localhost 9999Trying 127.0.0.1...Connected to localhost.Escape character is'^]'.versionVERSION 0.1.0statsSTAT pid 54937STATtime 1459634909STAT uptime 22STAT version 100STAT ru_stime 0.019172...

Pelikan is file-first when it comes to configurations, and currently isconfig-file only. You can create a new config file following the examplesincluded under theconfig directory.

• Join our project chat onfor questions and discussions
• Follow us on Twitter:@pelikan_cache
• Visithttp://pelikan.io

Please take a look at ourcommunity manifestoandcoding style guide.

If you want to submit a patch, please follow these steps:

1. create a new issue
2. fork on github & clone your fork
3. create a feature branch on your fork
4. push your feature branch
5. create a pull request linked to the issue

We have made progress and are actively working on documentation, and will put iton our website. Meanwhile, check out the current material underdocs/

This software is licensed under the Apache 2.0 license, seeLICENSE for details.