Transaction accelerator for client-server communication systems

• US 20060069719A1
• Filed: 09/15/2005
• Published: 03/30/2006
• Est. Priority Date: 10/30/2002
• Status: Active Grant

• Current Assignee: Riverbed Technology, LLC (Riverbed Technology Incorporated)
• Original Assignee: Riverbed Technology Incorporated
• Inventors: McCanne, Steven, Demmer, Michael J.
• Granted Patent: US 7,428,573 B2
• Time in Patent Office: Days
• US Class Current: 709/203
• CPC Class Codes: H04L 67/288 Distributed intermediate devices, i.e. intermediate devices for interaction with other intermediate devices on the same level
• CPC Class Codes: H04L 67/289 Intermediate processing functionally located close to the data consumer application, e.g. in same machine, in same home or in same sub-network
• CPC Class Codes: H04L 67/56 Provisioning of proxy services store-and-forward switching systems in data switching networks H04L12/54
• CPC Class Codes: H04L 67/5651 Reducing the amount or size of exchanged application data
• CPC Class Codes: H04L 67/5682 Policies or rules for updating, deleting or replacing the stored data
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]

Abstract

In a network having transaction acceleration, for an accelerated transaction, a client directs a request to a client-side transaction handler that forwards the request to a server-side transaction handler, which in turn provides the request, or a representation thereof, to a server for responding to the request. The server sends the response to the server-side transaction handler, which forwards the response to the client-side transaction handler, which in turn provides the response to the client. Transactions are accelerated by the transaction handlers by storing segments of data used in the transactions in persistent segment storage accessible to the server-side transaction handler and in persistent segment storage accessible to the client-side transaction handler. When data is to be sent between the transaction handlers, the sending transaction handler compares the segments of the data to be sent with segments stored in its persistent segment storage and replaces segments of data with references to entries in its persistent segment storage that match or closely match the segments of data to be replaced. The receiving transaction store reconstructs the data sent by replacing segment references with corresponding segment data from its persistent segment storage, requesting missing segments from the sender as needed. The transaction accelerators could handle multiple clients and/or multiple servers and the segments stored in the persistent segment stores can relate to different transactions, different clients and/or different servers. Persistent segment stores can be prepopulated with segment data from other transaction accelerators.

Claims

1. In a network wherein clients initiate transactions with servers and the network carries request messages from the clients to the servers and response messages from the servers to the client and wherein at least one of the request messages and the response messages contains a payload to be transported over the network from a sender to a receiver, a method of accelerating transactions comprising:

segmenting the payload into zero or more segments and zero or more symbols of unsegmented data;

for each of the segments, determining whether to send the segment data in the payload as an unreferenced segment or as a referenced segment;

for each of the referenced segments, replacing at least some of the segment data with a reference to the replaced data and storing the replaced reference data associated with its reference;

sending the payload from the sender to the receiver as an accelerated payload comprising zero or more segment references and zero or more symbols of unreferenced data;

receiving the accelerated payload over the network;

identifying the zero or more segment references in the accelerated payload;

replacing the one or more segment references in the accelerated payload with segment data available to the receiver, to form a reconstructed payload; and

providing the reconstructed payload to the receiver as the transported payload.

2. The method of claim 1, further comprising:

deploying two or more transaction accelerators in a network;

receiving the payload from a sender server or sender client at a first transaction accelerator;

sending the accelerated payload from the first transaction accelerator to a second transaction accelerator; and

sending the reconstructed payload from a second transaction accelerator to the receiving client or receiving server, such that the acceleration is transparent to the sender'"'"'s sending protocol and to the receivers'"'"' receiving protocol.

3. The method of claim 1, further comprising:

determining, at the transaction accelerator associated with the receiver, when segment data for a referenced segment is not available for payload reconstruction; and

requesting segment data from a transaction accelerator associated with the sender.

4. The method of claim 1, further comprising:

when segment data is to be stored as part of a segment reference, transforming the segment data via an invertible function of the segment data, and storing the results of this transformation; and

when segment data is to be used in dereferencing a segment, untransforming the stored results using an inverse of the invertible function.

5. The method of claim 4, wherein the invertible function is one or more of a forward error correction function, an encryption function and a signature function.

6. In a network wherein clients initiate transactions with servers and the network carries request messages from the clients to the servers and response messages from the servers to the client and wherein at least one of the request messages and the response messages contains a payload to be transported over the network from a sender to a receiver, a transaction accelerator comprising:

a transaction transformer for transforming a payload of a message to be sent, comprising;

a) a segmenter for segmenting the payload into zero or more segments and zero or more symbols of unsegmented data; and

b) a replacer for determining whether to represent the segment data of each segment as an unreferenced segment or as a referenced segment;

a persistent segment store that stores segment data and segment references for referenced segments;

an inverse transaction transformer for untransforming an accelerated payload from a transaction transformer of a remote transaction accelerator, comprising;

a) a tokenizer that determines where segment references appear in the accelerator payload; and

b) a dereferencer for substituting segment data from the persistent segment store for each segment reference detected by the tokenizer;

a reference resolver for resolving references as needed by the dereferencer when encountering a segment reference to a segment that is not present in the persistent segment store.

7. In a network wherein clients initiate transactions with servers and the network carries a request message from a client to a server and a response message from the server to the client and wherein at least one of the request message and the response message contains a payload to be transported over the network from a sender to a receiver, an improvement comprising:

a client-side transaction accelerator, comprising;

a) a proxy coupled to the client for receiving request messages for delivery to servers and for relating reconstructed response messages from the servers to the client;

b) a transaction transformer for transforming a request message received from the proxy, comprising;

i) a segmenter for segmenting the request message payload into zero or more segments and zero or more symbols of unsegmented data; and

ii) a replacer for determining whether to represent the segment data of each segment as an unreferenced segment or as a referenced segment;

c) a persistent segment store that stores segment data and segment references for referenced segments of the request message payload, wherein segments with distinct segment data have distinct segment references and the distinct segment references can be independent of the transaction in which the segment reference was created; and

d) an inverse transaction transformer for untransforming a response message payload into a reconstructed response message when the response message has been accelerated, comprising;

i) a tokenizer that determines where segment references appear in the response message payload; and

ii) a dereferencer for substituting segment data from the persistent segment store for each segment reference detected by the tokenizer; and

a server-side transaction accelerator, comprising;

a) a proxy coupled to the server for receiving response messages for delivery to clients and for relaying reconstructed request messages from clients to the server;

b) a transaction transformer for transforming a response message received from the proxy, comprising;

i) a segmenter for segmenting the response message payload into zero or more segments and zero or more symbols of unsegmented data; and

ii) a replacer for determining whether to represent the segment data of each segment as an unreferenced segment or as a referenced segment;

c) a persistent segment store that stores segment data and segment references for referenced segments of the response message payload, wherein segments with distinct segment data have distinct segment references and the distinct segment references can be independent of the transaction in which the segment reference was created; and

d) an inverse transaction transformer for untransforming a request message payload into a reconstructed request message when the request message has been accelerated, comprising;

i) a tokenizer that determines where segment references appear in the request message payload; and

ii) a dereferencer for substituting segment data from the persistent segment store for each segment reference detected by the tokenizer,

wherein at least one segment in either the request message payload or a response message payload is sent as a referenced segment.

8. The improvement of claim 7, further comprising:

a client-side reference resolver for resolving references as needed by the client-side dereferencer when encountering a segment reference to a segment that is not present in the client-side persistent segment store; and

a server-side reference resolver for resolving references as needed by the server-side dereferencer when encountering a segment reference to a segment that is not present in the server-side persistent segment store.

9. The improvement of claim 7, wherein one of the client-side transaction accelerator and the server-side transaction accelerator is a first transaction accelerator and the other one of the client-side transaction accelerator and the server-side transaction accelerator is a second transaction accelerator, the improvement further comprising:

means at the first transaction accelerator for anticipating segment requirements of the second transaction accelerator; and

means for conveying anticipated segments from the first transaction accelerator to the persistent segment store of the second transaction accelerator prior to the need of those anticipated segments by the dereferencer of the second transaction accelerator.

10. The improvement of claim 7, further comprising:

means, at each transaction accelerator of a set of transaction accelerators cooperating over a network, for allocating segment reference identifiers such that the segment reference identifiers are unique over the set of transaction accelerators, wherein the segment reference identifiers are selected from an effectively unbounded identifier space; and

means for compressing the segment identifiers to form compressed segment identifiers used in one or more of data storage and data transmission.