#database #mtbl #cdb #server #memcached

app cdbd

A little server that serves constant key-value store files (e.g. CDB and MTBL) via standard protocols (e.g. memcached)

2 releases

Uses old Rust 2015

0.1.1 Jun 7, 2017
0.1.0 Jun 7, 2017

#8 in #cdb




cdbd ("constant database daemon") is a small constant database server: given a key-value file in a format it understands (like CDB), it will serve that file via a protocol it speaks (like memcached).

In the past I have used a company-internal tool like cdbd (called "SSTable Service") to provide precomputed data to production services. The idea is that it's super easy to start a cdbd instance and get the data where you need. In a service-oriented architecture, cdbd makes your static data accessible.


echo '+3,5:one->Hello\n' | cdbmake f.cdb f.cdb.tmp
cdbd --cdb f.cdb --memcached 11211 &
memccat --servers=localhost:11211 one


Install with Cargo, the Rust package manager, like so:

cargo install cdbd


Usage: target/debug/cdbd [options]

        --memcached [HOST:]PORT
                        What port (and optional address) to bind a memcached
                        service on (default address "")
        --cdb CDB       A CDB file to serve
        --mtbl MTBL     An MTBL file to serve
    -v, --verbose       Print more logging information (may be used more than
                        once for more detail)
    -h, --help          Print this help text

Supported constant databases

  • CDB (with flag --cdb FILE)
  • MTBL (with flag --mtbl FILE)

Supported protocols

  • memcached (with flag --memcached [HOST:]PORT; supports memcached read operations only)

Work to be done

  • Loadtests and benchmarks
  • Use Tokio
  • Support other databases
    • LMDB
    • SQLite?
    • Berkeley DB?
  • Support other protocols
    • Redis (get and mget)
    • HTTP?
  • Pull protocols out into their own crates? It would allow others to write memcached etc. servers a little more easily, maybe.


Copyright 2017 Leon Barrett

Licensed under either of


Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.


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