diff --git a/geonames/challenges/default.json b/geonames/challenges/default.json
index 8a8d4fa6..5c38fa0e 100644
--- a/geonames/challenges/default.json
+++ b/geonames/challenges/default.json
@@ -62,87 +62,199 @@
         {
           "operation": "index-stats",
           "warmup-iterations": 500,
-          "iterations": 1000,
-          "target-throughput": 90
+          "iterations": 1000
+          {%- if not target_throughput %}
+          ,"target-throughput": 90
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%-if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "node-stats",
           "warmup-iterations": 100,
-          "iterations": 1000,
-          "target-throughput": 90
+          "iterations": 1000
+          {%- if not target_throughput %}
+          ,"target-throughput": 90
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%-if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "default",
           "warmup-iterations": 500,
-          "iterations": 1000,
-          "target-throughput": 50
+          "iterations": 1000
+          {%- if not target_throughput %}
+          ,"target-throughput": 50
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%-if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "term",
           "warmup-iterations": 500,
-          "iterations": 1000,
-          "target-throughput": 140
+          "iterations": 1000
+          {%- if not target_throughput %}
+          ,"target-throughput": 140
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%-if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "phrase",
           "warmup-iterations": 500,
-          "iterations": 1000,
-          "target-throughput": 140
+          "iterations": 1000
+          {%- if not target_throughput %}
+          ,"target-throughput": 140
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%-if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "country_agg_uncached",
           "warmup-iterations": 200,
-          "iterations": 100,
-          "target-throughput": 3.6
+          "iterations": 100
+          {%- if not target_throughput %}
+          ,"target-throughput": 3.6
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%-if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "country_agg_cached",
           "warmup-iterations": 1000,
-          "iterations": 1000,
-          "target-throughput": 100
+          "iterations": 1000
+          {%- if not target_throughput %}
+          ,"target-throughput": 100
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%-if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "scroll",
           "warmup-iterations": 200,
           "iterations": 100,
-          "#COMMENT": "Throughput is considered per request. So we issue one scroll request per second which will retrieve 25 pages",
-          "target-throughput": 0.8
+          "#COMMENT": "Throughput is considered per request. So we issue one scroll request per second which will retrieve 25 pages"
+          {%- if not target_throughput %}
+          ,"target-throughput": 0.8
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%-if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "expression",
           "warmup-iterations": 200,
-          "iterations": 100,
-          "target-throughput": 2
+          "iterations": 100
+          {%- if not target_throughput %}
+          ,"target-throughput": 2
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%-if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "painless_static",
           "warmup-iterations": 200,
-          "iterations": 100,
-          "target-throughput": 1.5
+          "iterations": 100
+          {%- if not target_throughput %}
+          ,"target-throughput": 1.5
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%-if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "painless_dynamic",
           "warmup-iterations": 200,
-          "iterations": 100,
-          "target-throughput": 1.5
+          "iterations": 100
+          {%- if not target_throughput %}
+          ,"target-throughput": 1.5
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%-if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "large_terms",
           "warmup-iterations": 200,
-          "iterations": 100,
-          "target-throughput": 1.1
+          "iterations": 100
+          {%- if not target_throughput %}
+          ,"target-throughput": 1.1
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%-if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "large_filtered_terms",
           "warmup-iterations": 200,
-          "iterations": 100,
-          "target-throughput": 1.1
+          "iterations": 100
+          {%- if not target_throughput %}
+          ,"target-throughput": 1.1
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%-if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "large_prohibited_terms",
           "warmup-iterations": 200,
-          "iterations": 100,
-          "target-throughput": 1.1
+          "iterations": 100
+          {%- if not target_throughput %}
+          ,"target-throughput": 1.1
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%-if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         }
       ]
     },
diff --git a/geopoint/challenges/default.json b/geopoint/challenges/default.json
index f2ed1dfc..6216d25b 100644
--- a/geopoint/challenges/default.json
+++ b/geopoint/challenges/default.json
@@ -60,26 +60,58 @@
         {
           "operation": "polygon",
           "warmup-iterations": 200,
-          "iterations": 100,
-          "target-throughput": 2
+          "iterations": 100
+          {%- if not target_throughput %}
+          ,"target-throughput": 2
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%-if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "bbox",
           "warmup-iterations": 200,
-          "iterations": 100,
-          "target-throughput": 2
+          "iterations": 100
+          {%- if not target_throughput %}
+          ,"target-throughput": 2
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%-if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "distance",
           "warmup-iterations": 200,
-          "iterations": 100,
-          "target-throughput": 5
+          "iterations": 100
+          {%- if not target_throughput %}
+          ,"target-throughput": 5
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%-if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "distanceRange",
           "warmup-iterations": 200,
-          "iterations": 100,
-          "target-throughput": 0.5
+          "iterations": 100
+          {%- if not target_throughput %}
+          ,"target-throughput": 0.5
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%-if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         }
       ]
     },
diff --git a/http_logs/challenges/default.json b/http_logs/challenges/default.json
index 5ee5eb87..0f19627b 100644
--- a/http_logs/challenges/default.json
+++ b/http_logs/challenges/default.json
@@ -58,33 +58,73 @@
         {
           "operation": "default",
           "warmup-iterations": 500,
-          "iterations": 100,
-          "target-throughput": 8
+          "iterations": 100
+          {%- if not target_throughput %}
+          ,"target-throughput": 8
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%-if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "term",
           "warmup-iterations": 500,
-          "iterations": 100,
-          "target-throughput": 50
+          "iterations": 100
+          {%- if not target_throughput %}
+          ,"target-throughput": 50
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%-if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "range",
           "warmup-iterations": 100,
-          "iterations": 100,
-          "target-throughput": 1
+          "iterations": 100
+          {%- if not target_throughput %}
+          ,"target-throughput": 1
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%-if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "hourly_agg",
           "warmup-iterations": 100,
-          "iterations": 100,
-          "target-throughput": 0.2
+          "iterations": 100
+          {%- if not target_throughput %}
+          ,"target-throughput": 0.2
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%-if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "scroll",
           "warmup-iterations": 100,
           "iterations": 200,
-          "#COMMENT": "Throughput is considered per request. So we issue one scroll request per second which will retrieve 25 pages",
-          "target-throughput": 1
+          "#COMMENT": "Throughput is considered per request. So we issue one scroll request per second which will retrieve 25 pages"
+          {%- if not target_throughput %}
+          ,"target-throughput": 1
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%-if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         }
       ]
     },
diff --git a/nested/challenges/default.json b/nested/challenges/default.json
index 505c45b1..01bebb11 100644
--- a/nested/challenges/default.json
+++ b/nested/challenges/default.json
@@ -58,52 +58,115 @@
         },
         {
           "operation": "randomized-nested-queries",
-          "clients": 2,
-          "target-throughput": 20,
           "warmup-iterations": 500,
           "iterations": 1000
+          {%- if not target_throughput %}
+          ,"target-throughput": 20
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%- if not search_clients %}
+          ,"clients": 2
+          {%- elif search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "randomized-term-queries",
-          "clients": 2,
-          "target-throughput": 25,
           "warmup-iterations": 500,
           "iterations": 200
+          {%- if not target_throughput %}
+          ,"target-throughput": 25
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%- if not search_clients %}
+          ,"clients": 2
+          {%- elif search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "randomized-sorted-term-queries",
-          "clients": 2,
           "warmup-iterations": 500,
-          "target-throughput": 16,
           "iterations": 200
+          {%- if not target_throughput %}
+          ,"target-throughput": 16
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%- if not search_clients %}
+          ,"clients": 2
+          {%- elif search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "match-all",
-          "clients": 2,
-          "target-throughput": 5,
           "warmup-iterations": 500,
           "iterations": 200
+          {%- if not target_throughput %}
+          ,"target-throughput": 5
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%- if not search_clients %}
+          ,"clients": 2
+          {%- elif search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "nested-date-histo",
-          "clients": 2,
-          "target-throughput": 1,
           "warmup-iterations": 100,
           "iterations": 200
+          {%- if not target_throughput %}
+          ,"target-throughput": 1
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%- if not search_clients %}
+          ,"clients": 2
+          {%- elif search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "randomized-nested-queries-with-inner-hits_default",
-          "clients": 2,
-          "target-throughput": 18,
           "warmup-iterations": 500,
           "iterations": 1000
+          {%- if not target_throughput %}
+          ,"target-throughput": 18
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%- if not search_clients %}
+          ,"clients": 2
+          {%- elif search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "randomized-nested-queries-with-inner-hits_default_big_size",
-          "clients": 2,
-          "target-throughput": 16,
           "warmup-iterations": 500,
           "iterations": 1000
+          {%- if not target_throughput %}
+          ,"target-throughput": 16
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%- if not search_clients %}
+          ,"clients": 2
+          {%- elif search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         }
       ]
     },
diff --git a/noaa/challenges/default.json b/noaa/challenges/default.json
index 25905a0a..8ecc62cc 100644
--- a/noaa/challenges/default.json
+++ b/noaa/challenges/default.json
@@ -59,50 +59,114 @@
         {
           "operation": "range_field_big_range",
           "warmup-iterations": 100,
-          "iterations": 500,
-          "target-throughput": 8
+          "iterations": 500
+          {%- if not target_throughput %}
+          ,"target-throughput": 8
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%-if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "range_field_small_range",
           "warmup-iterations": 100,
-          "iterations": 500,
-          "target-throughput": 10
+          "iterations": 500
+          {%- if not target_throughput %}
+          ,"target-throughput": 10
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%-if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "range_field_conjunction_big_range_small_term_query",
           "warmup-iterations": 100,
-          "iterations": 500,
-          "target-throughput": 10
+          "iterations": 500
+          {%- if not target_throughput %}
+          ,"target-throughput": 10
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%-if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "range_field_conjunction_small_range_small_term_query",
           "warmup-iterations": 100,
-          "iterations": 500,
-          "target-throughput": 10
+          "iterations": 500
+          {%- if not target_throughput %}
+          ,"target-throughput": 10
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%-if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "range_field_conjunction_small_range_big_term_query",
           "warmup-iterations": 100,
-          "iterations": 500,
-          "target-throughput": 4
+          "iterations": 500
+          {%- if not target_throughput %}
+          ,"target-throughput": 4
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%-if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "range_field_conjunction_big_range_big_term_query",
           "warmup-iterations": 100,
-          "iterations": 500,
-          "target-throughput": 1
+          "iterations": 500
+          {%- if not target_throughput %}
+          ,"target-throughput": 1
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%-if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "range_field_disjunction_small_range_small_term_query",
           "warmup-iterations": 100,
-          "iterations": 500,
-          "target-throughput": 10
+          "iterations": 500
+          {%- if not target_throughput %}
+          ,"target-throughput": 10
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%-if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "range_field_disjunction_big_range_small_term_query",
           "warmup-iterations": 100,
-          "iterations": 500,
-          "target-throughput": 6
+          "iterations": 500
+          {%- if not target_throughput %}
+          ,"target-throughput": 6
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%-if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         }
       ]
     },
diff --git a/nyc_taxis/challenges/default.json b/nyc_taxis/challenges/default.json
index fb4bc3d6..68615a74 100644
--- a/nyc_taxis/challenges/default.json
+++ b/nyc_taxis/challenges/default.json
@@ -54,20 +54,44 @@
         {
           "operation": "default",
           "warmup-iterations": 50,
-          "iterations": 100,
-          "target-throughput": 3
+          "iterations": 100
+          {%- if not target_throughput %}
+          ,"target-throughput": 3
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%- if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "range",
           "warmup-iterations": 50,
-          "iterations": 100,
-          "target-throughput": 0.7
+          "iterations": 100
+          {%- if not target_throughput %}
+          ,"target-throughput": 0.7
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%- if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "distance_amount_agg",
           "warmup-iterations": 50,
-          "iterations": 100,
-          "target-throughput": 2
+          "iterations": 100
+          {%- if not target_throughput %}
+          ,"target-throughput": 2
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%- if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         }
       ]
     },
diff --git a/percolator/challenges/default.json b/percolator/challenges/default.json
index cac23ccf..9e567197 100644
--- a/percolator/challenges/default.json
+++ b/percolator/challenges/default.json
@@ -59,38 +59,86 @@
         {
           "operation": "percolator_with_content_president_bush",
           "warmup-iterations": 100,
-          "iterations": 100,
-          "target-throughput": 50
+          "iterations": 100
+          {%- if not target_throughput %}
+          ,"target-throughput": 50
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%- if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "percolator_with_content_saddam_hussein",
           "warmup-iterations": 100,
-          "iterations": 100,
-          "target-throughput": 50
+          "iterations": 100
+          {%- if not target_throughput %}
+          ,"target-throughput": 50
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%- if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "percolator_with_content_hurricane_katrina",
           "warmup-iterations": 100,
-          "iterations": 100,
-          "target-throughput": 50
+          "iterations": 100
+          {%- if not target_throughput %}
+          ,"target-throughput": 50
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%- if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "percolator_with_content_google",
           "warmup-iterations": 100,
-          "iterations": 100,
-          "target-throughput": 30
+          "iterations": 100
+          {%- if not target_throughput %}
+          ,"target-throughput": 30
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%- if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "percolator_no_score_with_content_google",
           "warmup-iterations": 100,
-          "iterations": 100,
-          "target-throughput": 100
+          "iterations": 100
+          {%- if not target_throughput %}
+          ,"target-throughput": 100
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%- if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "percolator_with_highlighting",
           "warmup-iterations": 100,
-          "iterations": 100,
-          "target-throughput": 50
+          "iterations": 100
+          {%- if not target_throughput %}
+          ,"target-throughput": 50
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%- if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "percolator_with_content_ignore_me",
@@ -102,8 +150,16 @@
         {
           "operation": "percolator_no_score_with_content_ignore_me",
           "warmup-iterations": 100,
-          "iterations": 100,
-          "target-throughput": 15
+          "iterations": 100
+          {%- if not target_throughput %}
+          ,"target-throughput": 15
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%- if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         }
       ]
     }
\ No newline at end of file
diff --git a/pmc/challenges/default.json b/pmc/challenges/default.json
index a1790f5c..0eb754ca 100644
--- a/pmc/challenges/default.json
+++ b/pmc/challenges/default.json
@@ -68,38 +68,86 @@
         {
           "operation": "default",
           "warmup-iterations": 500,
-          "iterations": 200,
-          "target-throughput": 20
+          "iterations": 200
+          {%- if not target_throughput %}
+          ,"target-throughput": 20
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%- if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "term",
           "warmup-iterations": 500,
-          "iterations": 200,
-          "target-throughput": 20
+          "iterations": 200
+          {%- if not target_throughput %}
+          ,"target-throughput": 20
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%- if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "phrase",
           "warmup-iterations": 500,
-          "iterations": 200,
-          "target-throughput": 20
+          "iterations": 200
+          {%- if not target_throughput %}
+          ,"target-throughput": 20
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%- if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "articles_monthly_agg_uncached",
           "warmup-iterations": 500,
-          "iterations": 200,
-          "target-throughput": 20
+          "iterations": 200
+          {%- if not target_throughput %}
+          ,"target-throughput": 20
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%- if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "articles_monthly_agg_cached",
           "warmup-iterations": 500,
-          "iterations": 200,
-          "target-throughput": 20
+          "iterations": 200
+          {%- if not target_throughput %}
+          ,"target-throughput": 20
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%- if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         },
         {
           "operation": "scroll",
           "warmup-iterations": 50,
-          "iterations": 100,
-          "target-throughput": 0.5
+          "iterations": 100
+          {%- if not target_throughput %}
+          ,"target-throughput": 0.5
+          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
+          {%- else %}
+          ,"target-throughput": {{ target_throughput | tojson }}
+          {%- endif %}
+          {%- if search_clients is defined and search_clients %}
+          ,"clients": {{ search_clients | tojson}}
+          {%- endif %}
         }
       ]
     },