Abstract: The present invention discloses an alternative arrangement to wake-on-LAN and which is designed specifically for multi-tenant cloud computing and virtualized server environments. This new arrangement identifies which tenants or applications of a multi-tenant server are idle, and when a tenant or application is identified as idle, it transparently reduces the reserved computational capacity footprint of the application or tenant without shutting down the tenancy or exiting the application. Furthermore, the near-instantaneous resumption of the idle tenant or application is achieved when some external event is detected which relates to the passivated tenant or application.

Abstract: A method and system for operating a modified Java Virtual Machine (JVM) which is able to simultaneously host multiple Java application programs is disclosed. In a first modification the JVM is modified to permit multiple class definitions of some of the Java Application Programming Interface (API) classes, so called non-sensitive classes, to be loaded multiple times but restrict other Java API classes, so called sensitive classes, to be loaded only once, preferably onto a bootstrap class loader. In a second modification the Java API classes are also modified. Preferably in a further modification, some or all of the sensitive API classes are modified not to use synchronization.

Abstract: A method of enhancing secure operation of a computer is disclosed. The computer receives input data from an untrusted source and also operates an application program which can utilize the input data. The method involves creating a tainted value cache and storing the input data in that cache. In the event that the application program invokes a method which utilizes data from the cache, then that data is intercepted before it is utilized by the application program. The intercepted data is subjected to a data content test. If the intercepted data passes the data content test, then the intercepted data is forwarded to the application program to be utilized thereby. However, if the intercepted data fails the data content test, a security action is implemented.

Abstract: A computer architecture providing enhanced JVM security and a method of providing enhanced security for a JVM are disclosed. The host computer runs a single, first, trusted JAVA API library above which is located a hypervisor software layer, and then at least one untrusted JAVA API library. The code of each second, upper, untrusted JAVA API library is modified at, or before runtime to call the hypervisor software layer instead of the JVM to thereby create a silo corresponding to each of the second, upper, untrusted JAVA API libraries. Each silo extends between the host computer and the corresponding second, upper, untrusted JAVA API library. The hypervisor software layer is operated to only permit communication between each of the second, upper, untrusted JAVA API libraries and a corresponding portion of the memory and functional assets of the host computer.

Abstract: A method and system for operating a modified Java Virtual Machine (JVM) which is able to simultaneously host multiple Java application programs is disclosed. In a first modification the JVM is modified to permit multiple class definitions of some of the Java Application Programming Interface (API) classes, so called non-sensitive classes, to be loaded multiple times but restrict other Java API classes, so called sensitive classes, to be loaded only once, preferably onto a bootstrap class loader. In a second modification the Java API classes are also modified. Preferably in a further modification, some or all of the sensitive API classes are modified not to use synchronization.

Abstract: The present invention discloses an alternative arrangement to wake-on-LAN and which is designed specifically for multi-tenant cloud computing and virtualized server environments. This new arrangement identifies which tenants or applications of a multi-tenant server are idle, and when a tenant or application is identified as idle, it transparently reduces the reserved computational capacity footprint of the application or tenant without shutting down the tenancy or exiting the application. Furthermore, the near-instantaneous resumption of the idle tenant or application is achieved when some external event is detected which relates to the passivated tenant or application.