Batch-System-DOS-Pattern.md

+* Description: a user / work-group submits many short jobs to the workload manager. This results in waste due to pre-job and post-job overheads, slows down work-load manager
+
+* Criterion:
+  * Of 100 submitted batch-jobs the job-runtime is << 100x (Pre + Post Job Overhead)
+  * Multiple jobs of this category active at any time, or within a sliding window
+
+* Possible false positives: *
+
+* Possible cures / solutions:
+  * Aggregate multiple jobs into one batch job
+  * Use of job-arrays 
+
+
+```
+// rule on batch level
+{
+    "name":"Too Many Jobs",
+    "type":"bool",
+    "tag":"batchDOS",
+    "level":"jobs",
+    "metric(SLURM:jobID)":"jobIDs", // last 100 jobs for the user
+    "metric(SLURM:WTIME)":"jobWALLTimes",
+    "metric(SLURM:SubmitTime)":"jobSubmitTimes",
+    "parameter": ["max_submits_in_period","observation_period"] // <-- explicit list of used parameters? or can be gathered from code parsing?
+    "rule_terms":[
+        {"jobs_in_perdiod":       "SelectMetricIf(jobSubmitTimes,($$ - Now) < observation_period)"},
+        {"dos_alert":            "Carinality($jobs_in_period) > $max_submits_in_period)"},
+        {"job_submission_rate":       "$jobs_in_perdiod/$observation_period"},
+        {"max_job_submission_rate":       "$max_submits_in_period/$observation_period"},
+    ],  
+    "output":"dos_allert"
+    "output_metric":"$job_submission_rate"
+    "template":"The number of jobs sumbitted exceeded $max_job_submission_rate Jobs/Hour, was $job_submission_rate"
+}
+
+```
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