Managing the state of coupling facility structures

Abstract

A coupling facility is coupled to one or more other coupling facilities via one or more peer links. The coupling of the facilities enables various functions to be supported, including the duplexing of structures of the coupling facilities. Duplexing is performed on a structure basis, and thus, a coupling facility may include duplexed structures, as well as non-duplexed or simplexed structures.

1 . A method of managing the state of coupling facility structures, said method comprising: 
 obtaining a data structure to provide state of one or more structures of a coupling facility, said state relating to duplexing of said one or more structures, wherein the state of a structure of the one or more structures reflects whether the structure is duplexed in that a plurality of instances of the structure are concurrently updated to provide high availability of the structure; and    maintaining within the data structure state of the one or more structures.    
   
   
       2 . The method of  claim 1 , wherein said data structure comprises a vector having an indicator for each structure of the one or more structures.  
   
   
       3 . The method of  claim 2 , further comprising setting the indicator for a structure to activate duplexing of the structure.  
   
   
       4 . The method of  claim 3 , further comprising: 
 determining whether a remote coupling facility is connected to the coupling facility; and    setting the indicator, in response to a determination that the remote coupling facility is connected.    
   
   
       5 . The method of  claim 3 , further comprising resetting the indicator to deactivate duplexing.  
   
   
       6 . The method of  claim 5 , wherein the resetting causes a duplexed command issued after duplexing is deactivated to be suspended.  
   
   
       7 . The method of  claim 2 , wherein the vector is indexed by a structure identifier.  
   
   
       8 . The method of  claim 1 , wherein the state of a structure of one or more of the structures is used to control execution of one or more commands associated with the structure.  
   
   
       9 . A method of managing duplexing of coupling facility structures, said method comprising: 
 initiating activation of duplexing of a coupling facility structure, wherein an instance of the coupling facility structure is located within one coupling facility;    determining whether another coupling facility in which another instance of the coupling facility structure is to reside is connected to the one coupling facility; and    activating duplexing, in response to the determining indicating that the another coupling facility is connected to the one coupling facility.    
   
   
       10 . The method of  claim 9 , wherein said activating comprises setting in at least one data structure a duplexing indicator associated with the coupling facility structure.  
   
   
       11 . The method of  claim 9 , wherein the instance of the coupling facility structure and the another instance of the coupling facility structure are concurrently updated to provide high availability of the coupling facility structure.  
   
   
       12 . The method of  claim 9 , further comprising deactivating duplexing of the coupling facility structure, wherein the deactivating duplexing comprises resetting within at least one data structure a duplexing indicator associated with the coupling facility structure.  
   
   
       13 . The method of  claim 12 , wherein the resetting causes a duplexed command issued after duplexing is deactivated to be suspended.  
   
   
       14 . A memory for storing data accessible by one or more commands executing within a computing environment, said memory comprising: 
 a data structure to provide state of one or more structures of a coupling facility, said data structure comprising: 
 one or more indicators relating to duplexing of the one or more structures, wherein the state of a structure of the one or more structures reflects whether the structure is duplexed in that a plurality of instances of the structure are concurrently updated to provide high availability of the structure.  
   
   
   
       15 . A system of managing the state of coupling facility structures, said system comprising: 
 a data structure to provide state of one or more structures of a coupling facility, said state relating to duplexing of said one or more structures, wherein the state of a structure of the one or more structures reflects whether the structure is duplexed in that a plurality of instances of the structure are concurrently updated to provide high availability of the structure; and    a coupling facility to facilitate maintaining within the data structure state of the one or more structures.    
   
   
       16 . The system of  claim 15 , wherein said data structure comprises a vector having an indicator for each structure of the one or more structures, and said system further comprises means for setting the indicator for a structure to activate duplexing of the structure, wherein the setting is controlled by an operating system of a system coupled to the coupling facility.  
   
   
       17 . The system of  claim 16 , further comprising: 
 means for determining whether a remote coupling facility is connected to the coupling facility; and    wherein the means for setting the indicator comprises setting the indicator, in response to a determination that the remote coupling facility is connected.    
   
   
       18 . The system of  claim 16 , further comprising means for resetting the indicator to deactivate duplexing.  
   
   
       19 . The system of  claim 18 , wherein the resetting causes a duplexed command issued after duplexing is deactivated to be suspended.  
   
   
       20 . The system of  claim 15 , wherein the state of a structure of one or more of the structures is used to control execution of one or more commands associated with the structure.  
   
   
       21 . At least one program storage device readable by a machine tangibly embodying at least one program of instructions executable by the machine to perform a method of managing the state of coupling facility structures, said method comprising: 
 obtaining a data structure to provide state of one or more structures of a coupling facility, said state relating to duplexing of said one or more structures, wherein the state of a structure of one or more structures reflects whether the structure is duplexed in that a plurality of instances of the structure are concurrently updated to provide high availability of the structure; and    maintaining within the data structure state of the one or more structures.    
   
   
       22 . The at least one program storage device of  claim 21 , wherein said data structure comprises a vector having an indicator for each structure of the one or more structures, and wherein the vector is indexed by a structure identifier.  
   
   
       23 . The at least one program storage device of  claim 22 , wherein said method further comprises: 
 determining whether a remote coupling facility is connected to the coupling facility; and    setting the indicator for a structure, in response to a determination that the remote coupling facility is connected, to activate duplexing of the structure, wherein the setting is controlled by an operating system of a system coupled to the coupling facility.    
   
   
       24 . The at least one program storage device of  claim 23 , wherein said method further comprises resetting the indicator to deactivate duplexing, wherein the resetting is controlled by at least one of an operating system of a system coupled to the coupling facility and control code of the coupling facility, and wherein the resetting causes a duplexed command issued after duplexing is deactivated to be suspended.  
   
   
       25 . The at least one program storage device of  claim 21 , wherein the state of a structure of one or more of the structures is used to control execution of one or more commands associated with the structure.  
   
   
       26 . At least one program storage device readable by a machine tangibly embodying at least one program of instructions executable by the machine to perform a method of managing duplexing of coupling facility structures, said method comprising: 
 initiating activation of duplexing of a coupling facility structure, wherein an instance of the coupling facility structure is located within one coupling facility;    determining whether another coupling facility in which another instance of the coupling facility structure is to reside is connected to the one coupling facility; and    activating duplexing, in response to the determining indicating that the another coupling facility is connected to the one coupling facility.