Flexible failover configuration

• US 20060248198A1
• Filed: 04/29/2005
• Published: 11/02/2006
• Est. Priority Date: 04/29/2005
• Status: Active Grant

• Current Assignee: SAP SE
• Original Assignee: SAP AG (SAP SE)
• Inventors: Galchev, Galin
• Granted Patent: US 8,589,562 B2
• Time in Patent Office: Days
• US Class Current: 709/227
• CPC Class Codes: G06F 11/1438 Restarting or rejuvenating
• CPC Class Codes: G06F 11/1471 involving logging of persistent data for recovery
• CPC Class Codes: G06F 11/2035 without idle spare hardware
• CPC Class Codes: G06F 11/2043 where the redundant components share a common memory address space
• CPC Class Codes: G06F 11/2046 where the redundant components share persistent storage G06F11/2043 takes precedence
• CPC Class Codes: H04L 65/1066 Session management
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066

Abstract

A method is described that involves offering a user different persistent scope choices including: a) internal to a computing system that the deployment descriptor is to be sent to; and, b) external to the computing system that the deployment descriptor is to be sent to. The method also involves offering a user different persistence frequency choices including: a) persisting per request; and, b) persisting per session state information attribute change. The method also involves generating a deployment descriptor that reflects the user'"'"'s choice of the persistence scope and persistence frequency.

Claims

1. A method, comprising:

generating a first instance of a deployment descriptor and sending said first instance of said deployment descriptor to a first computing system, said first instance of said deployment descriptor specifying a persistence scope that does not extend beyond said first computing system, said first computing system having multiple virtual machines, said first computing system not having shared memory accessible to each of said virtual machines for storing persisted session information; and

,

generating a second instance of said deployment descriptor and sending said second instance of said deployment descriptor to a second computing system, said second instance of said deployment descriptor specifying a persistence scope that does not extend beyond said second computing system, said second computing system having multiple virtual machines, said second computing system having shared memory accessible to each of said second system'"'"'s virtual machines for storing persisted session information;

as a consequence of said first computing system receiving said first instance of said deployment descriptor, persisting a first session'"'"'s session state information in said first computing system'"'"'s file system; and

,

as a consequence of said second computing system receiving said second instance of said deployment descriptor, persisting a second session'"'"'s session state information in said second computing system'"'"'s shared memory.

2. The method of claim 1 further comprising:

generating a third instance of said deployment descriptor and sending said third instance of said deployment descriptor to a third computing system, said third instance of said deployment descriptor specifying a persistence scope that is external to said third computing system;

as a consequence of said third computing system receiving said third instance of said deployment descriptor, persisting a third session'"'"'s session state information in a database that is external to said third computing system.

3. The method of claim 1 wherein said first and second instances of said deployment descriptor specify a persistence frequency selected from the group consisting of:

persisting a session state attribute because a response will be, is, or has been generated;

persisting a session state attribute because said attribute has been changed.

4. The method of claim 1 wherein said second session'"'"'s session information comprises a plurality of attributes, each one of said attributes contained in a different object in said shared memory, each object not referencing another object containing one of said attributes.

5. The method of claim 1 further comprising instantiating a plug-in in said first computing system for said file system.

6. The method of claim 5 further comprising over the course of said first session, managing the persistence of said first session'"'"'s session state information in said file system by, with program code provided by said plug-in, translating a first command that is not specific to said file system into a second command that is specific to said file system, said session state information comprising a plurality of attributes, said first command to cause a process to be performed, said process selected from the group consisting of:

storing in said file system one of said attributes;

retrieving from said file system one of said attributes;

retrieving from said file system all of said attributes;

deleting from said file system all of said attributes;

retrieving from said file system a session identification for said session;

retrieving from said file system information used to determine if said session has expired; and

,

updating in said file system information used to determine if said session has expired.

7. The method of claim 6 wherein:

said one of said attributes is serialized prior to said storing; and

,

said one of said attributes is deserialized after said storing.

8. An article of manufacture including program code which, when executed by a machine, causes the machine to perform a method, the method comprising:

offering a user different persistence scope choices including;

a) internal to a computing system that said deployment descriptor is to be sent to;

b) external to said computing system that said deployment descriptor is to be sent to;

offering a user different persistence frequency choices including;

a) persisting per request;

b) persisting per session state attribute change; and

,

generating a deployment descriptor that reflects said user'"'"'s choice of said persistence scope and persistence frequency.

9. The article of manufacture of claim 8 wherein said deployment descriptor specifies whether said persistence is to be enabled or not enabled.

10. A computing system comprising a machine, said computing system also comprising instructions disposed on a computer readable medium, said instructions capable of being executed by said machine to perform a method, said method comprising:

offering a user different persistence scope choices including;

a) internal to a computing system that said deployment descriptor is to be sent to;

b) external to said computing system that said deployment descriptor is to be sent to;

offering a user different persistence frequency choices including;

a) persisting per session request;

b) persisting per session state information attribute change; and

,

generating a deployment descriptor that reflects said user'"'"'s choice of said persistence scope and persistence frequency.

11. The computing system of claim 10 wherein said deployment descriptor specifies whether said persistence is to be enabled or not enabled.