Information technology service management

1. An information technology (IT) service management method, comprising:

storing a desired instance of a service model, the service model specifying characteristics of an IT service;

storing an observed instance of the service model;

comparing the observed instance to the desired instance;

detecting an inconsistency between the desired instance and the observed instance based on the comparison; and

assigning, using a watchdog service and based on the detected inconsistency, a watched state to an instance of the service model associated with the desired instance and the observed instance, wherein the watched state indicates that the instance is usable but under scrutiny.

2. The method of claim 1 , further comprising:

modifying the desired instance in response to detecting the inconsistency.

3. The method of claim 1 , further comprising:

modifying the observed instance in response to detecting the inconsistency.

4. The method of claim 1 , further comprising:

determining when the detected inconsistency returns to a consistent state; and

notifying the watchdog service when the detected inconsistency returns to the consistent state.

5. The method of claim 1 , wherein the inconsistency includes at least one of a degradation of performance and a system failure.

6. The method of claim 1 , wherein modifying the observed instance includes adding resources to the IT service.

7. The method of claim 1 , wherein modifying the observed instance includes changing the IT service configuration.

8. The method of claim 1 , further comprising:

assigning a maximum amount of time that the instance of the service model can remain in the watched state; and

assigning a repair state to the instance in response to determining that the instance was in the watched state for an amount of time exceeding the maximum amount of time.

9. The method of claim 1 , further comprising:

deploying complementary monitoring probes in response to the watched state being assigned to the instance.

10. The method of claim 1 , further comprising:

assigning a grounded state to the instance in response to determining that the inconsistency is no longer detected.

11. The method of claim 1 , further comprising:

deploying a complementary probe by a monitoring service in response to the watchdog service assigning the watched state to the instance.

12. An information technology (IT) service management system, comprising:

a configuration management system (CMS) including a memory storing a desired instance of a service model;

a monitoring service providing an observed instance of the service model to the configuration management system;

wherein the configuration management system is configured to detect an inconsistency between the desired instance and the observed instance based on the comparison; and

a watchdog service to assign, based on the detected inconsistency, a state to an instance of the service model associated with the desired instance and the observed instance, wherein the state is one of:

a watched state indicating that the instance is usable but under scrutiny; and

a repair state indicating that the instance is not usable.

13. The system of claim 12 , further comprising:

a repair service invoked in response to detection of the inconsistency by the CMS.

14. The system of claim 12 , further comprising:

the watchdog service invoked in response to detection of the inconsistency by the CMS.

15. The system of claim 12 , further comprising the CMS to modify the observed instance in response to detection of the inconsistency.

16. The system of claim 12 , further comprising the CMS to modify the desired instance in response to detection of the inconsistency.

17. A non-transitory computer readable medium storing instructions executable by a processing resource to cause a computer to:

store a desired instance of a service model, the service model specifying characteristics of an Information Technology (IT) service;

store an observed instance of the service model;

compare the observed instance to the desired instance;

detect an inconsistency between the desired instance and the observed instance based on the comparison; and

assign, using a watchdog service and based on the detected inconsistency, a repair state to an instance of the service model associated with the desired instance and the observed instance, wherein the repair state indicates that the instance is not usable.

18. The medium of claim 17 , further comprising instructions executable by a processing resource to cause a computer to:

modify the observed instance in response to detection of the inconsistency.

19. The medium of claim 18 , wherein the instructions executable to modify the observed instance include instructions executable to invoke a repair service.

20. The medium of claim 19 , further comprising instructions executable by a processing resource to cause a computer to:

disable the instructions to detect an inconsistency between the desired instance and the observed instance until the repair service has completed a repair of the detected inconsistency.