# Kalavara

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A distributed persistent key value store that speaks http. Inspired by
[minkeyvalue](https://github.com/geohot/minikeyvalue).

# installation

precompiled binaries are available on [release page](https://github.com/shanavas786/kalavara/releases) or
you can run `cargo install kalavara` command to install kalavara

# master server

Master server stores index (key, url of volume server where the value is
stored) in rocksdb. Requests are redirected to curresponding volume server
after metadata is updated.

to start the server, run

```sh
master -p 6000 -d /tmp/kalavadb -v http://volume1:6001 http://volume2:6002
```

# volume server

Volume server stores values in file system. For atomicity temporary files are
first created in `destdir/tmp` directory and then moved to destination path.
For this approach to work, `destdir/tmp` and destination path should be in same
file system

to start the volume server, run

```sh
volume -p 7000 -d /tmp/kalavarastore
```

if master server is not aware of this volume server, register with

```sh
volume -p 7000 -d /tmp/kalavarastore -m http://master.server -b http://this.volume.server:7000
```


## Usage

1. insert a key-value

```sh
curl -XPUT -L -d value http://localhost:6000/store/key
```

2. retrive value

```sh
curl -XGET -L http://localhost:6000/store/key
```

3. delete a key

```sh
curl -XDELETE -L http://localhost:6000/store/key
```

4. register a new volume server with master

```sh
curl -XPOST -d http://newvolume.server http://localhost:6000/admin/add-volume
```


# Performance

```sh
./wrk -t2 -c100 -d10s http://localhost:6000/missingkey
Running 10s test @ http://localhost:6000/missingkey
  2 threads and 100 connections
  Thread Stats   Avg      Stdev     Max   +/- Stdev
    Latency     2.04ms    1.61ms  28.98ms   83.07%
    Req/Sec    21.33k     4.76k   34.42k    66.00%
  426423 requests in 10.07s, 65.88MB read
  Non-2xx or 3xx responses: 426423
Requests/sec:  42359.95
Transfer/sec:      6.54MB

```

# License

<p xmlns:dct="http://purl.org/dc/terms/"
  xmlns:vcard="http://www.w3.org/2001/vcard-rdf/3.0#"> <a rel="license"
  href="http://creativecommons.org/publicdomain/zero/1.0/"> <img
  src="http://i.creativecommons.org/p/zero/1.0/88x31.png" style="border-style:
  none;" alt="CC0" /> </a> <br />

To the extent possible under law, the author(s) have dedicated all copyright
related and neighboring rights to this software to the public domain worldwide.
This software is distributed without any warranty.

</p>