Comet Maturity Guide

We recently asked our contributors to outline the maturity of their preferred Comet server implementation. The summary of those questions are outlined here. If you want to add info about your Comet implementation, please contact us.

Version: 0.5 (Dec 12, 2009)

Caplin Liberator Cometd (Python) ErlyComet GlassFish Jetty Lightstreamer Meteor Orbited Persevere RMDS2Web Server
General
Status Production Beta Alpha Production Production Production Production Beta Production Production
Version 4.5.9 0.9 Alpha 3 7.0.1 3.x 1.06 0.7.x 1.0 1.6
License Commercial BSD MIT Apache 2.0 or Commercial Apache 2.0 Commercial GPL v2 MIT BSD or AFL Commercial
Pricing Free or Commercial Free Free Free or Commercial Free Free or Commercial Free Free Free Commercial
Protocols RTTP (Real Time Text Protocol) Bayeux Bayeux Bayeux Bayeux Lightstreamer Network Protocol Transports are completely configurable within simple constraints Revolved HTTP Channels and Bayeux negotiation Proprietary
Message Delivery Guarantee Yes No Yes Yes Yes Yes Yes Yes Yes Yes
Dedicated Comet Server Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes
Platforms
Unix/Linux Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes
Mac No Yes Yes Yes Yes Yes Yes Yes Yes Yes
Windows No Yes Yes Yes Yes Yes Yes Yes Yes Yes
Languages
Server C Python Erlang Java Java Java Perl Python Java/JavaScript Java
Server APIs C, Java, .Net Python Erlang Java Java Java, .NET, TCP sockets Perl Python Java, JavaScript Java
Client APIs (in addition to JavaScript) Java, .Net, Silverlight Python Erlang Java Java Flash, Flex, Java (SE/ME), .NET Many Many
Transports
Polling Yes Yes Yes Yes Yes Yes Yes Yes Yes No
Long-Polling No Yes Yes Yes Yes Yes Yes Yes Yes No
Callback-Polling No Yes Yes Yes Yes No Yes Yes No No
Iframe Streaming Yes No No Yes No Yes Yes Yes No No
htmlfile Streaming Yes No No Yes No No Yes Yes No Yes
XHR Streaming Yes No No Yes No No Yes Yes Yes Yes
Multipart Streaming Yes No No Yes No No Yes Yes No Yes
Server Sent Events No No No No No No Yes Yes No Yes
Direct Socket Yes No No No No Yes No No No No
HTML5 WebSocket No Yes Yes No Yes Yes No Yes Yes No
Scaling
Horizonal (multiple nodes) Yes No Yes Yes Yes Yes Yes Yes No Yes
Vertical 30,000 clients max. 1 million total client updates/sec at 10,000 clients TBD TBD Sun achieved 883.66 JOPS@Standard on a single app server instance running on a Sun Fire T2000 server. That translates to over 7000 simultaneous active user Jetty/Bayeux can support 20,000 simultaneous clients per node with several thousands of messages per second. Jetty/ActiveMQ has been able to deliver 7,000 price changes per second to 40,000 users over a 3 node cluster. 20,000 - 100,000 (depends only on the message throughputs, not on the number of clients) 1000 clients per node receiving 2 msgs (~400 bytes) per sec each. Tested up to 5000 clients per node receiving 1 msg/sec each Tested against 10,000 idling clients without issue on Intel core duo 1.6 GHz TBD 500,000 concurrent clients each client receiving 2.4 updates per minute with 17 millisecond end-to-end latency from a single entry-level server DELL SC1435. High throughput: 8,000 concurrent clients each client receiving 100 updates per second with 270 millisecond end-to-end latency from a single Dell SC1435.
Caplin Liberator Cometd (Python) ErlyComet GlassFish Jetty Lightstreamer Meteor Orbited Persevere RMDS2Web Server
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