Agent-based event-driven web server architecture

• US 7,747,707 B1
• Filed: 07/31/2007
• Issued: 06/29/2010
• 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:
  US11/888,005
• Time in Patent Office: 1,064 Days
• Field of Search: 709/217, 709/218, 709/219
• 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. An intermediate networking device positioned between a client and a target server, the networking device comprising:

a processor;

an operating system executing on the processor;

a web server application program executing as a process on the operating system of the device, wherein the web server application program receives data from the client by a client socket of the operating system and forwards the data from the intermediate networking device to the target server;

an event-based signaling mechanism within the operating system that triggers operating system-level signaling events in response to data arriving on the client socket, 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; 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 web server 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 remaining ones of the other operating system-level events to enter the event queue, and

wherein, in response to detecting one of the operating system-level signaling events in the event queue, the web server 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 socket and forwards the data from the intermediate networking device to the target server.

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

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

4. The device of claim 3, 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.

5. The device of claim 4, wherein the state machine subsystem includes a forward state machine that writes data to the socket associated with the requesting client.

6. The device of claim 5, 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.

7. The device of claim 6, wherein the state machine subsystem includes a server session state machine that manages manage network communications with the 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.

8. The device of claim 7, wherein the state machine subsystem includes the multiplexing agent that controls the flow of data between the client session state machine and one or more server session state machines.

9. The device of claim 1,

wherein the event queue comprises a first event queue,

wherein the event-based signaling mechanism triggers an operating system-level signaling event in response data arriving on the server sockets,

wherein the filter passes the operating system-level signaling events that are in response to data arriving on the server sockets to the event queue, and

wherein the web server application program detects an event in the second queue, and, in response, reads data of off the server socket associated with the target server and forwards the data from the intermediate networking device to the client.

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

receiving data from a client at a client socket on an intermediate networking device located between the client and a target server;

creating operating system-level events in response to each of receiving the data on the client socket and at least one of connection request completion, disconnection request initiation, disconnection request completion, partial connection shutdown, data being sent to server sockets, and asynchronous errors;

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

detecting the events passed to the event queue from a component of a web server application program executed on the networking device;

in response to detecting the events passed to the event queue, reading data off of the client socket with the web server application program without polling the client socket first to determine that the data is ready to be read from the 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, further comprising receiving data from the target server at the networking device in response to the data sent to the target server from the networking device.

12. The method of claim 11, forwarding the data received from the target server from the networking device to the client.

13. An intermediate network device located between a plurality of clients and a target server, the intermediate network device comprising:

a web server application program executing on an operating system having client sockets for communicating with the clients and a plurality of server sockets for communicating with the target server;

an operating system-level event-based means for triggering a signaling event in response to each of the arrival of data on any of the client sockets and at least one other condition unrelated to data arriving on the client sockets; and

filter means for filtering the signaling events triggered by the event-based means such that only the events that are in response to arrival of data on any of the client sockets are provided to an event queue,

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

14. The device of claim 13, wherein the at least one other condition unrelated to data arriving on the client sockets comprises at least one of connection request completion, disconnection request initiation, disconnection request completion, partial connection shutdown, data being sent to server sockets, and asynchronous errors.

15. A computer readable storage medium comprising instructions that cause a processor to:

receive data from a client at a client socket on an intermediate networking device located between the client and a target server;

create operating system-level events in response to each of receiving the data on the client socket and at least one of connection request completion, disconnection request initiation, disconnection request completion, partial connection shutdown, data being sent to server sockets, and asynchronous errors;

filter the operating system-level events to pass only the events that are in response to receiving the data on the client socket to an event queue of an operating system executing on the processor;

detect the events passed to the event queue from a component of a web server application program executed on the networking device;

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

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

16. The computer readable medium of claim 15, further comprising instructions that cause the processor to:

receive data from the target server at the networking device in response to the data sent to the target server from the networking device; and

forward the data received from the target server from the networking device to the client.