Open, Search, Close Old Indexes

I have a request to search through 200 closed indexes for some data. Our current cluster is running well but at the edge of what it can handle. I don't want to open all the necessary indexes at one time to avoid overloading the cluster.

I like to open the index, search it, collect data and close it back down. I understand I will hit the system with a good amount of overhead doing this.

Is there a better way to do this?

The cluster is a 5.6.16 version and is due for upgrades latter this year. It is currently at this version while software that relies on it is upgraded to handle the newer Elasticsearch versions.

Cluster Stats if helpful

     "completion" : {
          "size" : "0b",
          "size_in_bytes" : 0
        },
        "segments" : {
          "count" : 15334,
          "memory" : "49gb",
          "memory_in_bytes" : 52700563987,
          "terms_memory" : "38.1gb",
          "terms_memory_in_bytes" : 40990621926,
          "stored_fields_memory" : "9gb",
          "stored_fields_memory_in_bytes" : 9754110992,
          "term_vectors_memory" : "0b",
          "term_vectors_memory_in_bytes" : 0,
          "norms_memory" : "3.6mb",
          "norms_memory_in_bytes" : 3878464,
          "points_memory" : "1.5gb",
          "points_memory_in_bytes" : 1642141873,
          "doc_values_memory" : "295.4mb",
          "doc_values_memory_in_bytes" : 309810732,
          "index_writer_memory" : "52.4mb",
          "index_writer_memory_in_bytes" : 55039064,
          "version_map_memory" : "2.1mb",
          "version_map_memory_in_bytes" : 2294006,
          "fixed_bit_set" : "0b",
          "fixed_bit_set_memory_in_bytes" : 0,
          "max_unsafe_auto_id_timestamp" : -1,
          "file_sizes" : { }
        }
      },
      "nodes" : {
        "count" : {
          "total" : 7,
          "data" : 3,
          "coordinating_only" : 0,
          "master" : 3,
          "ingest" : 7
        },
        "versions" : [
          "5.6.16"
        ],
        "os" : {
          "available_processors" : 104,
          "allocated_processors" : 104,
          "names" : [
            {
              "name" : "Linux",
              "count" : 7
            }
          ],
          "mem" : {
            "total" : "226gb",
            "total_in_bytes" : 242713886720,
            "free" : "43.8gb",
            "free_in_bytes" : 47133552640,
            "used" : "182.1gb",
            "used_in_bytes" : 195580334080,
            "free_percent" : 19,
            "used_percent" : 81
          }
        },
        "process" : {
          "cpu" : {
            "percent" : 9
          },
          "open_file_descriptors" : {
            "min" : 255,
            "max" : 6302,
            "avg" : 2823
          }
        },
        "jvm" : {
          "max_uptime" : "20d",
          "max_uptime_in_millis" : 1735647149,
          "versions" : [
            {
              "version" : "1.8.0_232",
              "vm_name" : "OpenJDK 64-Bit Server VM",
              "vm_version" : "25.232-b09",
              "vm_vendor" : "Private Build",
              "count" : 5
            },
            {
              "version" : "1.8.0_222",
              "vm_name" : "OpenJDK 64-Bit Server VM",
              "vm_version" : "25.222-b10",
              "vm_vendor" : "Private Build",
            },
    {
      "_nodes" : {
        "total" : 7,
        "successful" : 7,
        "failed" : 0
      },
      "cluster_name" : "wildcard-graylog",
      "timestamp" : 1580148140391,
      "status" : "green",
      "indices" : {
        "count" : 684,
        "shards" : {
          "total" : 6506,
          "primaries" : 3253,
          "replication" : 1.0,
          "index" : {
            "shards" : {
              "min" : 6,
              "max" : 28,
              "avg" : 9.511695906432749
            },
            "primaries" : {
              "min" : 3,
              "max" : 14,
              "avg" : 4.755847953216374
            },
            "replication" : {
              "min" : 1.0,
              "max" : 1.0,
              "avg" : 1.0
            }
          }
        },
        "docs" : {
          "count" : 21190208302,
          "deleted" : 2055179
        },
        "store" : {
          "size" : "27.6tb",
          "size_in_bytes" : 30443808755847,
          "throttle_time" : "0s",
          "throttle_time_in_millis" : 0
        },
        "fielddata" : {
          "memory_size" : "520.2mb",
          "memory_size_in_bytes" : 545556728,
          "evictions" : 0
        },
        "query_cache" : {
          "memory_size" : "5gb",
          "memory_size_in_bytes" : 5403289588,
          "total_count" : 20900349,
          "hit_count" : 1532613,
          "miss_count" : 19367736,
          "cache_size" : 24106,
          "cache_count" : 28752,
          "evictions" : 4646
        },
        "completion" : {
          "size" : "0b",
          "size_in_bytes" : 0
        },
        "segments" : {
          "count" : 15334,
          "memory" : "49gb",
          "memory_in_bytes" : 52700563987,
          "terms_memory" : "38.1gb",
          "terms_memory_in_bytes" : 40990621926,
          "stored_fields_memory" : "9gb",
          "stored_fields_memory_in_bytes" : 9754110992,
          "term_vectors_memory" : "0b",
          "term_vectors_memory_in_bytes" : 0,
          "norms_memory" : "3.6mb",
          "norms_memory_in_bytes" : 3878464,
          "points_memory" : "1.5gb",
          "points_memory_in_bytes" : 1642141873,
          "doc_values_memory" : "295.4mb",
          "doc_values_memory_in_bytes" : 309810732,
          "index_writer_memory" : "52.4mb",
          "index_writer_memory_in_bytes" : 55039064,
          "version_map_memory" : "2.1mb",
          "version_map_memory_in_bytes" : 2294006,
          "fixed_bit_set" : "0b",
          "fixed_bit_set_memory_in_bytes" : 0,
          "max_unsafe_auto_id_timestamp" : -1,
          "file_sizes" : { }
        }
      },
      "nodes" : {
        "count" : {
          "total" : 7,
          "data" : 3,
          "coordinating_only" : 0,
          "master" : 3,
          "ingest" : 7
        },
        "versions" : [
          "5.6.16"
        ],
        "os" : {
          "available_processors" : 104,
          "allocated_processors" : 104,
          "names" : [
            {
              "name" : "Linux",
              "count" : 7
            }
          ],
          "mem" : {
            "total" : "226gb",
            "total_in_bytes" : 242713886720,
            "free" : "43.8gb",
            "free_in_bytes" : 47133552640,
            "used" : "182.1gb",
            "used_in_bytes" : 195580334080,
            "free_percent" : 19,
            "used_percent" : 81
          }
        },
        "process" : {
          "cpu" : {
            "percent" : 9
          },
          "open_file_descriptors" : {
            "min" : 255,
            "max" : 6302,
            "avg" : 2823
          }
        },
        "jvm" : {
          "max_uptime" : "20d",
          "max_uptime_in_millis" : 1735647149,
          "versions" : [
            {
              "version" : "1.8.0_232",
              "vm_name" : "OpenJDK 64-Bit Server VM",
              "vm_version" : "25.232-b09",
              "vm_vendor" : "Private Build",
              "count" : 5
            },
            {
              "version" : "1.8.0_222",
              "vm_name" : "OpenJDK 64-Bit Server VM",
              "vm_version" : "25.222-b10",
              "vm_vendor" : "Private Build",
              "count" : 1
            },
            {
              "version" : "11.0.5",
              "vm_name" : "OpenJDK 64-Bit Server VM",
            "heap_max_in_bytes" : 100661395456
              "vm_version" : "11.0.5+10-post-Ubuntu-0ubuntu1.118.04",
              "vm_vendor" : "Private Build",
              "count" : 1
            }
          ],
          "mem" : {
            "heap_used" : "70.4gb",
            "heap_used_in_bytes" : 75626306200,
            "heap_max" : "93.7gb",
            "heap_max_in_bytes" : 100661395456
          },
          "threads" : 1151
        },
        "fs" : {
          "total" : "126.6tb",
          "total_in_bytes" : 139234065371136,
          "free" : "88.4tb",
          "free_in_bytes" : 97247962710016,
          "available" : "88.4tb",
          "available_in_bytes" : 97235960922112,
          "spins" : "true"
        },
        "plugins" : [ ],
        "network_types" : {
          "transport_types" : {
            "netty4" : 7
          },
          "http_types" : {
            "netty4" : 7
          }
        }
      }
    }