Method for secure in-service software upgrades

1 . A method for upgrading a software program, the method comprising:

installing a first component running a first version of a software program in an active mode;

installing a second component running the first version of the software program in a standby mode;

installing a third component running a second version of the software program in a standby mode;

synchronizing state information of the first component with the third component;

switching the third component to an active mode and the first component to a standby mode after the state information of the first component is at least partially synchronized with the third component;

removing the second component;

installing a fourth component running the second version of the software program in a standby mode; and

synchronizing state information of the third component with the fourth component;

removing the first component.

2 . The method according to claim 1 , further comprising:

switching the fourth component to an active mode and the third component to a standby mode after the state information of the third component is at least partially synchronized with the fourth component.

3 . The method according to claim 1 , wherein the first component is installed on a first node in a network having at least a first and a second node.

4 . The method according to claim 3 , wherein the second component is installed on a second node in the network.

5 . The method according to claim 1 , wherein the third component is installed on a second node in a network having at least a first and a second node.

6 . The method according to claim 1 , wherein the fourth component is installed on a first node in a network having at least a first and a second node.

7 . The method according to claim 1 , wherein the state information includes at least one value in at least one memory location.

8 . The method according to claim 1 , wherein the standby mode is a mode of operation where the component monitors state values of at least one other component.

9 . A computer program product for upgrading a software program, the computer program product comprising:

a storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising:

installing a first component running a first version of a software program in an active mode;

installing a second component running the first version of the software program in a standby mode;

installing a third component running a second version of the software program in a standby mode;

synchronizing state information of the first component with the third component;

switching the third component to an active mode and the first component to a standby mode after the state information of the first component is at least partially synchronized with the third component;

removing the second component;

installing a fourth component running the second version of the software program in a standby mode;

synchronizing state information of the third component with the fourth component; and

removing the first component.

10 . The computer program product according to claim 9 , further comprising:

switching the fourth component to an active mode and the third component to a standby mode after the state information of the third component is at least partially synchronized with the fourth component.

11 . The computer program product according to claim 9 , wherein the first component is installed on a first node in a network having at least a first and a second node.

12 . The computer program product according to claim 11 , wherein the second component is installed on a second node in the network.

13 . The computer program product according to claim 9 , wherein the third component is installed on a second node in a network having at least a first and a second node.

14 . The computer program product according to claim 9 , wherein the fourth component is installed on a first node in a network having at least a first and a second node.

15 . The computer program product according to claim 9 , wherein the state information includes at least one value in at least one memory location.

16 . The computer program product according to claim 9 , wherein the standby mode is a mode of operation where the component monitors state values of at least one other component.

17 . A method for upgrading a software program in a multi-node network, the method comprising:

installing a third component running a second version of a software program in a standby mode on a second node of a multi-node network, the second node having a second component running a first version of the software program in a standby mode;

synchronizing state information of a first component running a first version of a software program in an active mode on a first node within the multi-node network with the third component;

switching the third component to an active mode and the first component to a standby mode after the state information of the first component is at least partially synchronized with the third component;

removing the second component from the second node;

installing a fourth component running a second version of the software program in a standby mode on the first node; and

synchronizing state information of the third component with the fourth component;

removing the first component from the first node.

18 . The computer program product according to claim 17 , further comprising:

switching the fourth component to an active mode and the third component to a standby mode after the state information of the third component is at least partially synchronized with the fourth component.

19 . The method according to claim 17 , wherein the state information includes at least one value in at least one memory location.

20 . The method according to claim 17 , wherein the standby mode is a mode of operation where the component monitors state values of at least one other component.