ElasticSearch search exception after migration 1.0.3 from 0.90.x

Question

We are migrating our ES cluster from 0.90 to 1.x (1.0.3), after following ES migration guides from

https://github.com/elasticsearch/elasticsearch/blob/2c777cef24603f2b7d79bd23c450dbc23927a24a/docs/reference/migration/migrate_1_0.asciidoc#search-request-source-filtering

Our app is a heavy-user of dynamic scripting (earlier accomplished with custom_score which is now changed to function_score) and uses boosting via script for search rankings. Though Tire doesn't support ES 1.x officially we are working on a fork to add 1.x fixes (https://github.com/dbose/retire/commit/1e90b159d645ec171c0e83b4e8301a432b72e246) before slowly moving to elasticsearch-ruby/rails client, which is now the officially library.

The problem is, our search works first time. But from next time onwards, ES crashes on the same query with following error

[2014-11-28 14:12:55,828][DEBUG][action.search.type       ] [Black Lama] [development-business][2], node[2yW9bVjbSLqyl3FkXXy_zw], [P], s[STARTED]: Failed to execute [org.elasticsearch.action.search.SearchRequest@31b8c5e3] lastShard [true]
org.elasticsearch.search.query.QueryPhaseExecutionException: [development-business][2]: query[filtered(function score (-company.exact: +(ops_status:new ops_status:active ops_status:claim_pending ops_status:claim_original ops_status:pending ops_status:paymentpending) +(customer_status:paymentpending customer_status:active customer_status:awaiting_payment customer_status:jumpstart) +domain_ids:[34834 TO 34834], functions: [{filter(*:*), function [script[relativeDistance = def(lat1, lon1, lat2, lon2) {
  if(lat1 == nil || lon1 == nil || lat2 == nil || lon2 == nil) {
    return 2147483647;
  }

  return Math.pow(lat2-lat1, 2) + Math.pow(lon2-lon1, 2);
};
closestPoint = def(lat, lon, output) {
  if(lat == nil || lon == nil) {
    return (output == 'object' ? _source.locations[0] : _score);
  }

  closest = 2147483647;
  closest_location = _source.locations[0];
  for(loc : _source.locations) {
    d = relativeDistance(loc.geo_point.lat, loc.geo_point.lon, lat, lon);
    if(closest > d) { closest = d; closest_location = loc; }
  };

  return (output == 'object' ? closest_location : closest);
};
coverageScore = def(region_id, region_type, region_ancestors) {
  weights = [60000, 50000, 40000, 30000, 20000, 10000];
  weight_index = 0;
  if(region_type == "suburb") { region_type = "location" }

  // find the region or its subregions
  types = ["national", "state", "region", "area", "location", "suburb"];
  active = false;
  for(type: types) {
    if(active || region_type == type){
      active = true;
      items = (type != "location" ? _source.serviced_areas : _source.locations);
      for(item: items) {
        if((type == "location" || item.region_type == type) && item[region_type] == region_id) {
          return weights[weight_index];
        }
      }
      weight_index += 1;
    }
  }

  // now expand to larger regions
  ancestor_index = 0;
  active = false;
  reversed_types = ["suburb", "location", "area", "region", "state", "national"];
  for(type: reversed_types) {
    if(active) {
      items = (type != "location" ? _source.serviced_areas : _source.locations);
      for(item: items) {
        if((type == "location" || item.region_type == type) && item.id == region_ancestors[ancestor_index]) {
          return weights[weight_index];
        }
      }
      ancestor_index += 1;
      weight_index += 1;
    }
    else if(region_type == type) {
      active = true;
    }
  }

  // didn't match anything
  return 0;
};
matchKeyword = def(keyword, keywords_weightings) {
  for(kw: keywords_weightings) {
    if(kw.keyword == keyword) {
      return kw.weighting;
    }
  }
  return 0.0;
};
categoryKeywordWeightingScore = def(keywords) {
  //for(keyword: keywords) {
  //  score_to_add += matchKeyword(keyword, _source.category_keywords);
  //}
  for(kw: _source.category_keywords) {
    if(kw.keyword == keywords) {
      return kw.weighting;
    }
  }
  return 0.0; // TODO: normalise this
};
primaryCategoryScore = def(category_id) {
  for(id : _source.category_ids) {
    if(id == category_id) {
      return 10000;
    }
  }
  return 0;
};
score = _score;

// CATEGORY + KEYWORD SCORING

primary_category_bonus = primaryCategoryScore(category_id);
score += primary_category_bonus;

if(primary_category_bonus == 0) {
  score += categoryKeywordWeightingScore(keywords);
}

// FEATURED BUSINESSES SCORING

for(featured : _source.featured_businesses) {
  if (featured.domain_id == domain_id && featured.category_id == category_id) {
    score += 10000000 * (1 + featured.level);
  }
}

// BUSINESS TIER SCORING

score += _source.plan_ranking * 100000;

// LOCATION SCORING

if (_source.locations != null) {

  if (_source.serviced_areas != null) {
    // score by coverage areas (locations + serviced areas)
    score += coverageScore(region_id, region_type, region_ancestors);
  }

  // score by distance
  point = closestPoint(lat, lon, 'object');
  if (point.id != region_id) {
    score += (10.0/(relativeDistance(point.geo_point.lat, point.geo_point.lon, lat, lon) + 0.001));
  }
}

// CONTENT SCORING

if (_source.company_lower == keywords) {
  score += 750000;
}

if (_source.primary_domain_id == domain_id) {
  score += 100;
}

if (_source.phone_number != null && _source.phone_number != "") {
  score += 50;
}

if (_source.star_rating != null && _source.star_rating > 0) {
  score += _source.star_rating * 50;
}

return score;
], params [{primaryCategoryScore=org.elasticsearch.common.mvel2.ast.PrototypalFunctionInstance@7bf90a55, _source=org.elasticsearch.search.lookup.SourceLookup@97a8b43, matchKeyword=org.elasticsearch.common.mvel2.ast.PrototypalFunctionInstance@4c4ce091, region_ancestors=[0], score=0.12918511, region_id=2, _score=0.12918511, coverageScore=org.elasticsearch.common.mvel2.ast.PrototypalFunctionInstance@46750a05, categoryKeywordWeightingScore=org.elasticsearch.common.mvel2.ast.PrototypalFunctionInstance@2de4f266, region_name=nsw, _FREQUENCIES=8, _fields=org.elasticsearch.search.lookup.FieldsLookup@11e61e14, lat=0.0, region_type=state, _PAYLOADS=4, lon=0.0, keywords=, domain_id=34834, _index=org.elasticsearch.search.lookup.IndexLookup@1ac0bc3a, category_id=null, closestPoint=org.elasticsearch.common.mvel2.ast.PrototypalFunctionInstance@6385918e, _doc=org.elasticsearch.search.lookup.DocLookup@561734ad, doc=org.elasticsearch.search.lookup.DocLookup@561734ad, relativeDistance=org.elasticsearch.common.mvel2.ast.PrototypalFunctionInstance@d837603, _CACHE=32, _OFFSETS=2, _POSITIONS=16}]]}]))->cache(_type:business)],from[0],size[20]: Query Failed [Failed to execute main query]
 at org.elasticsearch.search.query.QueryPhase.execute(QueryPhase.java:126)
 at org.elasticsearch.search.SearchService.executeQueryPhase(SearchService.java:249)
 at org.elasticsearch.search.action.SearchServiceTransportAction.sendExecuteQuery(SearchServiceTransportAction.java:202)
 at org.elasticsearch.action.search.type.TransportSearchQueryThenFetchAction$AsyncAction.sendExecuteFirstPhase(TransportSearchQueryThenFetchAction.java:80)
 at org.elasticsearch.action.search.type.TransportSearchTypeAction$BaseAsyncAction.performFirstPhase(TransportSearchTypeAction.java:216)
 at org.elasticsearch.action.search.type.TransportSearchTypeAction$BaseAsyncAction.performFirstPhase(TransportSearchTypeAction.java:203)
 at org.elasticsearch.action.search.type.TransportSearchTypeAction$BaseAsyncAction$2.run(TransportSearchTypeAction.java:186)
 at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895)
 at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918)
 at java.lang.Thread.run(Thread.java:680)

Any clues to debug this would be fantastic ! Thanks guys