Method and system for reducing message passing for contention detection in distributed SIP server environments

A computer program product comprising a computer readable hardware storage device having readable program code stored on the computer readable hardware storage device, the program code comprising:

• program code to obtain a local Wait-For Graph (WFG) at a first site of a distributed Session Initiation Protocol (SIP) server environment;
• program code to determine that a first transaction at the first site is waiting for a first object locked by a second transaction at a second site based on the local WFG at the first site;
• program code to send a first probe to the second site to determine whether the second site is waiting;
• program code to receive a second probe at the first site indicating that another site of the distributed server environment is waiting for an object locked by the first site, wherein the second probe further indicates to the first site a deadlock in the distributed SIP server environment to be resolved;
• program code to receive an indication of the deadlock in the distributed SIP server environment to be resolved;
• program code to resolve the deadlock in the distributed SIP server environment by victimizing the first transaction at the first site that is waiting for the first object;
• and
• program code to take into account a likelihood of an actual data lock issue happening for a given set of objects locked by a given set of transactions.

A computer system for detecting and resolving a deadlock in a distributed server environment, the system comprising:

• one or more computer processors;
• a computer readable hardware storage device;
• and
• program instructions stored on the computer readable hardware storage device for execution by the one or more computer processors, the program instructions comprising:
• program instructions to obtain a local Wait-For Graph (WFG) at a first site of a distributed Session Initiation Protocol (SIP) server environment;
• program instructions to determine that the first site is waiting for a first object locked by a second site based on the WFG at the first site;
• program instructions to send a first probe to the second site to determine whether the second site is waiting;
• program instructions to receive a second probe at the first site indicating that another site of the distributed server environment is waiting for an object locked by the first site, wherein the second probe further indicates to the first site a deadlock in the distributed SIP server environment to be resolved;
• program instructions to receive an indication of the deadlock in the distributed SIP server environment to be resolved;
• program instructions to resolve the deadlock in the distributed SIP server environment by victimizing a transaction at the first site that is waiting for the first object;
• and
• program instructions to obtain a dependence between transaction initiators and objects and forming reducts of such initiators and objects involved in data locks.