1. Distributed Policy Management and Comprehension with Classified Advertisements

2. A Distributed Policy Scenario
A user submits a job to Condor
The user has designed a policy defining requested services
Machines in condor pool have policies restricting the use of services
The user’s job won’t run - Why?
Is user’s policy to restrictive?
Was job rejected by machine policies?

3. Policy Management Resource allocation challenges
Resource heterogeneity
Policy heterogeneity
How to allocate resources?
Conventional centralized allocation not sufficient
Solution: Matchmaking with Classified Advertisements (ClassAds)

4. Matchmaking ?
Job

5. ? Matchmaking Job MyType = “Machine”; [ MyType = “Job”; .............
Rank = ...
Requirements = ... ]
MyType = “Machine”; ?
Job

6. ? Matchmaking Job MyType = “Machine”; [ MyType = “Job”; .............
Rank = ...
Requirements = ... ]
MyType = “Machine”; ?
Job

7. ? Matchmaking Job MyType = “Machine”; [ MyType = “Job”; .............
Rank = ...
Requirements = ... ]
MyType = “Machine”; ?
Job

8. Classified Advertisements
Represent entities (e.g. jobs, machines) and their policies
A ClassAd is a set of named expressions called attributes
Types of attributes:
Characteristics of an entity (Arch, OpSys, Memory)
Constraints for requested resource (Requirements)
Preferences for requested resource (Rank)

9. Typical Classads [ [ Type = “Job”; Type = “Machine”;
Owner = “ncoleman”;
Cmd = “run_sim”;
Memory = 31m;
Rank = KFlops/1E3 + other.Memory/32;
Requirements = (other.Type == “Machine”) && (other.Arch == “INTEL”)
&& (other.Opsys == “LINUX”)
&& (other.Memory >= 128); ] [
Type = “Machine”;
KeybrdIdle = ‘00:23:12’;
Memory = 256M;
LoadAvg = ;
Kflops = 21893;
Arch = “INTEL”;
OpSys = “LINUX”;
Name = “foo.cs.wisc.edu”;
Rank = (DayTime() >= ‘9:00’)
&& ((DayTime() <= ‘17:00’) ?
1/other.ImageSize : 0);
Requirements = (other.Type == “Job”)
&& (other.Owner != “riffraff”)
&& (LoadAvg < 0.3)
&& (KeybrdIdle > ‘00:15’); ]

10. Policy Comprehension Why won’t my job run? Looking for answers
My policy is too restrictive
My job is rejected by machines in the pool
Looking for answers
Use condor tools (condor_q, condor_status)
Stare at job ClassAd to find out what’s wrong

11. Condor Tools condor_q –analyze: User wants more details:
Of 105 resource offers,
105 do not satisfy the request's constraints
64 resource offer constraints are not satisfied by this request
User wants more details:
Which parts of job requirements expression are problematic?
Is job ClassAd missing any attributes?

12. Two Cases to Examine 1. No machines meet the job’s requirements
2. The job does not meet any machine’s requirements
One or both of these issues may be preventing the job from running, but they are not interdependent. We can analyze each one separately.

13. Example 1 JOB [ Requirements = (Arch==“SPARK”) &&(OpSys==“SOLARIS2.7”)]

14. JOB
Example 1 [
Requirements = (Arch==“SPARK”)
&&(OpSys==“SOLARIS2.7”) ]
Result:
(Arch == “SPARK"): did not match - suggestion: REMOVE
(Opsys == "SOLARIS2.7"): matched: 2 - suggestion: KEEP

15. Example 2 JOB [ Requirements = (Arch==“ALPHA”) && (OpSys==“WINNT”)
&& (Memory>=64) ]

16. JOB
Example 2 [
Requirements = (Arch==“ALPHA”)
&& (OpSys==“WINNT”)
&& (Memory>=64) ]
Result:
(Arch == "ALPHA"): matched: 1 - suggestion: REMOVE
(OpSys == "WINNT"): matched: 2 - suggestion: KEEP
(Memory >= 64): matched: 4 - suggestion: KEEP

17. Example 3 JOB MACHINES 1 4 2 5 3 [ Owner = “jsmith”;
ImageSize = ;
Requirements = ... ]
MACHINES [
Requirements = (ImageSize <= 50176)
&& (MemoryReq < 49) ] 1 [
Requirements = (ImageSize <= 50176)
&& (MemoryReq < 49) ] 4 [
Requirements = (ImageSize <= 50176)
&& (MemoryReq < 49) ] 2 [
Requirements = (ImageSize <= )
&& (MemoryReq < 98) ] 5 [
Requirements = (ImageSize <= )
&& (MemoryReq < 98) ] 3

18. + ¥
115712
3,5
ImageSize
50176
1,2,3,4,5
3,5
+ ¥ 49 98
MemoryReq

19. Example 3 JOB Results of Test ---------------[
Owner = “jsmith”;
ImageSize = ;
Requirements = ... ]
Results of Test
The following attributes are missing from the job classad:
MemoryReq
The following attributes should be added or modified:
ImageSize: - suggestion: use a value less than or equal to 50176
MemoryReq: - suggestion: use a value less than 49

20. Current Work ClassAd analysis prototype implemented in Java
Job requirements analysis
Machine requirements analysis
Current version supports a simple menu driven interface
Working on integrating with Condor tools
condor_q –analyze
condor_status

21. Future Work Applications to other uses of ClassAds in Condor
Analysis of a successful match
Graphical interface
Analysis of gang matching
ClassAds as an authorization language

22. Conclusions
Automated fine grained policy expression analysis is useful and feasible
Different issues arise with job requirements analysis and machine requirements analysis
The ClassAd language is ideal for these purposes.