stompserver

stompserver by Patrick Hurley, Lionel Bouton http://stompserver.rubyforge.org/

== DESCRIPTION:

Stomp messaging server with file/dbm/memory/activerecord based FIFO queues, queue monitoring, and basic authentication.

== SYNOPSYS:

Handles basic message queue processing

== REQUIREMENTS:

• EventMachine

== FEATURES/PROBLEMS:

=== Several queue storage backends

Handles basic message queue processing using memory, file, or dbm based queues. Messages are sent and consumed in FIFO order (unless a client error happens, this should be corrected in the future). Topics are memory-only storage. You can select activerecord, file or dbm storage and the queues will use that, but topics will only be stored in memory.

memory queues are of course the fastest ones but shouldn't be used if you want to ensure all messages are delivered.

dbm queues will use berkeleydb if available, otherwise dbm or gdbm depending on the platform. sdbm does not work well with marshalled data. Note that these queues have not been tested in this release.

For the file based storage, each frame is stored in a single file. The first 8 bytes contains the header length, the next 8 bytes contains the body length, then the headers are stored as a marshalled object followed by the body stored as a string. This storage is currently inefficient because queues are stored separately from messages, which forces a double write for data safety reasons on each message stored.

The activerecord based storage expects to find a database.yml file in the configuration directory. It should be the most robust backend, but the slowest one. The database must have an ar_messages table which can be created with the following code (you are responsible to do so):

ActiveRecord::Schema.define do create_table 'ar_messages' do |t| t.column 'stomp_id', :string, :null => false t.column 'frame', :text, :null => false end end

You can read the frames with this model:

class ArMessage < ActiveRecord::Base serialize :frame end

The ar_message implementation will certainly change in the future.

This is meant to be easily readable by a Rails application (which could handle the ar_messages table creation with a migration).

=== Limitations

Stompserver not support any server to server messaging (although you could write a client to do this).

=== Monitoring

Queues can be monitored via the monitor queue (this will probably not be supported this way in the future to avoid polluting the queue namespace). If you subscribe to /queue/monitor, you will receive a status message every 5 seconds that displays each queue, it's size, frames enqueued, and frames dequeued. Stats are sent in the same format of stomp headers, so they are easy to parse. Following is an example of a status message containing stats for 2 queues:

Queue: /queue/client2 size: 0 dequeued: 400 enqueued: 400

Queue: /queue/test size: 50 dequeued: 250 enqueued: 300

=== Access control

Basic client authorization is also supported. If the -a flag is passed to stompserver on startup, and a .passwd file exists in the run directory, then clients will be required to provide a valid login and passcode. See passwd.example for the password file format.

=== Misc

Whenever you stop the server, any queues with no messages will be removed, and the stats for that queue will be reset. If the queue has any messages remaining then the stats will be saved and available on the next restart.

== INSTALL:

• gem install stompserver

stompserver will create a log, etc, and storage directory on startup in your current working directory, the value passed to as --working_dir parameter, or if using a config file it will use what you specified for working_dir. The configuration file is a yaml file and can be specified on the command line with -C . A sample is provided in config/stompserver.conf.

Command line options will override options set in the yaml config file.

To use the memory queue run as follows: stompserver -p 61613 -b 0.0.0.0

To use the file or dbm queue storage, use the -q switch and specificy either file or dbm. The file and dbm queues also take a storage directory specified with -s. .stompserver is the default directory if -s is not used. stompserver -p 61613 -b 0.0.0.0 -q file -s .stompfile Or stompserver -p 61613 -b 0.0.0.0 -q dbm -s .stompbdb

To specify where the queue is stored on disk, use the -s flag followed by a storage directory. To enable client authorization use -a, for debugging use -d. stompserver -p 61613 -b 0.0.0.0 -q file -s .stompserver -a -d

You cannot use the same storage directory for a file and dbm queue, they must be kept separate.

To use the activerecord queue storage use -q activerecord: stompserver -p 61613 -b 0.0.0.0 -q activerecord It will try to read the etc/database.yml file in the working directory. Here's an example of a database.yml for a PostgreSQL database named stompserver on the 'dbserver' host usable by PostgreSQL's user 'foo' with password 'bar'(see ActiveRecord's documentation for the parameters needed by your database):

adapter: postgresql database: stompserver username: foo password: bar host: dbserver

== LICENSE:

(The MIT License)

Copyright (c) 2006 Patrick Hurley Copyright (c) 2007 Lionel Bouton

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.