Agent-based event-driven web server architecture

• US 7,917,601 B1
• Filed: 06/04/2010
• Issued: 03/29/2011
• Est. Priority Date: 10/10/2000
• Status: Expired due to Fees

• Current Assignee: Juniper Networks Incorporated
• Original Assignee: Juniper Networks Incorporated
• Inventors: Peiffer, Christopher
• Primary Examiner(s): Chan; Wing F
• Assistant Examiner(s): Miah; Razu A
• Application Number:
  US12/794,564
• Time in Patent Office: 298 Days
• Field of Search: 709217-219, 370/532
• US Class Current: 709/219
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]

Abstract

A networking device, method, and web server software architecture are provided. The device may include a web server application program configured to run on an operating system of the device, and an event-based signaling mechanism configured to signal the web server application program when data has arrived on a socket of the operating system, by triggering an operating system-level signaling event. The web server application program is configured to read data off of the socket in response to detecting the event, without polling the socket first to determine that data is ready to be read from the socket.

Claims

1. A networking device comprising:

a processor;

an operating system executing on the processor;

an application program executing as a process on the operating system of the device, wherein the application program receives data from a client device by a client socket of the operating system, wherein the networking device is positioned between the client device and a target server;

an event-based signaling mechanism within the operating system that triggers operating a system-level signaling event in response to each of a plurality of conditions associated with the client socket including data arriving on the client socket and at least one other condition associated with the client socket; and

a filter and an event queue within the operating system, the event queue of the operating system being associated with the client socket and accessible by the application program,

wherein the filter within the operating system receives the operating system-level signaling events and passes to the event queue only those operating-system-level events that were triggered in response to data arriving on the client socket without allowing any events that were triggered in response to any of the other conditions associated with the client socket to enter the event queue, and

wherein, in response to detecting one of the operating system-level signaling events in the event queue, the application program reads the data off of the client socket without polling the client socket first to determine that data is ready to be read from the client socket and forwards the data from the networking device to the target server.

2. The device of claim 1, wherein the other conditions associated with the client socket that trigger the operating-system level events include a completion of a connection request for the client socket, an initiation of a disconnection request for the client socket, a completion of the disconnection request for the client socket, a partial connection shutdown for the client socket, data being sent to server sockets, and asynchronous errors with respect to the client socket.

3. The device of claim 1, wherein the application program operates as a proxy server, such that the application program receives requests from the client, sends the requests to a target server, receives responses from the target server, and forwards the responses to the requesting clients.

4. The device of claim 1, wherein the application program includes a state machine subsystem.

5. The device of claim 4, wherein the state machine subsystem includes a first accept state machine that detects an event within the event queue, and, in response, read data off of the client socket associated with the requesting client.

6. The device of claim 5, wherein the state machine subsystem includes a forward state machine that writes data to the socket associated with the requesting client.

7. The device of claim 6, wherein the state machine subsystem includes a client session state machine that manages network communications with the requesting client, via the socket associated with the client, the first accept machine, and the forward state machine.

8. The device of claim 7, wherein the state machine subsystem includes a server session state machine that manages manage network communications with a target server, via server sockets associated with the target server, a second accept machine configured to read data from a server socket associated with the target server, and a target state machine configured to write data to a socket associated with a target server.

9. The device of claim 8, wherein the state machine subsystem includes a multiplexing agent that controls the flow of data between the client session state machine and one or more server session state machines.

10. A method for serving web resources, the method comprising:

receiving data from a client at a client socket on a intermediate networking device positioned between the client and at least one target server;

creating operating system-level events in response to each of a plurality of conditions associated with the client socket, wherein the plurality of conditions includes data arriving on the client socket and at least one other condition;

filtering the operating system-level events to pass to an event queue only the events that are created in response to receiving the data on the client socket;

detecting the events passed to the event queue from an application program executing on the networking device; and

in response to detecting the events passed to the event queue, reading data from the client socket with the application program without polling the client socket first to determine that the data is ready to be read from the client socket; and

forwarding the data read off of the client socket from the intermediate networking device to the target server.

11. The method of claim 10, wherein the other conditions associated with the client socket that trigger the operating-system level events include a completion of a connection request for the client socket, an initiation of a disconnection request for the client socket, a completion of the disconnection request for the client socket, a partial connection shutdown for the client socket, data being sent to server sockets, and asynchronous errors with respect to the client socket.

12. The method of claim 10, further comprising receiving data from the target server at the intermediate networking device in response to the data sent to the target server from the intermediate networking device.

13. The method of claim 10, further comprising forwarding the data received from the target server from the intermediate networking device to the client.