Johanna

Johanna is a server implementation of the Hannah session server hannahd and is written in Java.

Usage

$ java org.oneandone.idev.johanna.JohannahServer [--port=2001] \
  [--backend=memory|redis] \
  [--host=127.0.0.1] \
  [--identifier=md5|uuid]

or - if you run the uber-jar:

$ java -jar /path/to/johanna-jar.jar  [--port=2001] \
  [--backend=memory|redis] \
  [--host=127.0.0.1] \
  [--identifier=md5|uuid]

port: defaults to 2001.
backend: supports memory (keep sessions in RAM), redis (use Redis key-value store as session storage).
host: host of Redis store
identifier: use MD5 or UUID as session identifier implementation

Implemented protocol commands

The following commands are implemented:

session_create <ttl>
session_terminate <id>
session_isvalid <id>
session_settimeout <id> <ttl>
session_keys <id>
var_write <id> <stor> <name> <value>
var_read <id> <stor> <name>
var_delete <id> <stor> <name>
bye and exit

Parameters explained:

<id> is a session unique identifier generated by the server
<ttl> is a timeout in seconds
<stor> is the type of storage, it can be tmp, perm or sec. Currently only tmp is implemented
<name> is a whitespace delimited key name
<value> is a whitespace delimited value` - a common approach to store arbitrary data there is to first urlencode the data.

Prerequisites

The build requires Java 7
A non-global dependency jcli is contained in the contrib/ folder

Protocol

Basics

The Hannah-protocol is a line-based, human readable & writable protocol. Clients issue a command, the server replies. There are no server-initiated actions on the wire.