Patent ID: 8527809

Claim:
A system, comprising: interceptors configured to intercept fork( ) and exec( ); a checkpointer structured to checkpoint and restore applications that use fork( ) and exec( ), and structured to incrementally checkpoint and restore applications that write memory pages from kernel space; one or more computer nodes of a distributed system upon which one or more applications can be loaded and executed; a high-availability services module is structured to be executable on the one or more computer nodes for loss-less migration of the one or more applications, and is operable to perform checkpointing and restoration of all state in a transport connection; a shared memory comprising one or more shared memory locations; and wherein said checkpointer is configured to store in said shared memory at least one of a global application state including checkpoint barrier information having a barrier semaphore ID, a Virtual PID table, a Pipe table, a Semaphore ID table, and a “SystemV shared memory segment ID” table; wherein the system is configured to upon issuing an exec call by an application, passing control of the application to the interceptors, calling, by the interceptors, an operating system exec( ), overlaying a new image onto an existing application process, using an environment variable to preserve across exec( ) a number of times a process has exec'ed, and running said interceptors for fork( ) an exec( ) in user-space; wherein the system is configured to call the application's entry point to run the application; wherein said shared memory is configured to be outside an address space of the applications; and wherein a custom_init( ) function is preloaded.