title: InfluxDB missing tag value (putInfluxDB nifi processor)
body: <p>i'm new in InfluxDB, the problem consists in that i have to insert python dicts in InfluxDB via Nifi and i have tried different ways and i allways got the same error telling that tag is missing:</p>
  
  <p><a href="https://i.stack.imgur.com/rfIkV.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/rfIkV.png" alt="enter image description here"></a></p>
  
  <pre><code>org.influxdb.InfluxDBException: {
      "error": "unable to parse '[
          {
            "measurement": "sensor",
            "time": 1559560006,
            "tags": [
              "sensor",
              "id",
              "date",
              "info",
              "aleatory_number",
              "aleatory_number_square_root"
            ],
            "fields": {
              "id": 8,
              "date": 1559559961002,
              "info": "info sensor8",
              "aleatory_number": 1778687859,
              "aleatory_number_square_root": 42174.492
            }
          }
        ]': missing tag value"
  } 
  </code></pre>
  
  <p>Another example:</p>
  
  <pre><code>{
    "error":"unable to parse 
    '[{
      "measurement":"sensor",
      "time":1559630455,
      "tags":{"test_tag":"test"},
      "fields":{}
      }]'
      : missing tag value"
  }
  </code></pre>
  
  <p>Another:</p>
  
  <pre><code>org.influxdb.InfluxDBException: 
  {
    "error":"unable to parse 
    '[{
      "measurement":"sensor",
      "time":1559631341,
      "tags":{},
      "fields":{}
      }]'
      : missing tag value"}
  </code></pre>
  
  <p>My last try follows this avro schema:</p>
  
  <pre><code>{
    "type": "record",
    "name": "preprocessed_value",
    "fields": [
      { "name": "measurement", "type": "string"  },
      { "name": "time", "type": "long"  },
      { "name": "tags", "type": { "type":"map", "values" : "string"}  },
      { 
        "name" : "fields" , 
        "type" : {
          "name" : "PythonDict",
          "type" : "record",
          "fields": [
            { "name": "id",                           "type": "int" },
            { "name": "date",                         "type": "long"  },
            { "name": "info",                         "type": "string"  },
            { "name": "aleatory_number",              "type": "long"  },
            { "name": "aleatory_number_square_root",  "type": "float" }
          ]
        } 
      }
    ]
  }
  </code></pre>
  
  <p>And i got the same error using tags and fields simultaneously:</p>
  
  <pre><code>org.influxdb.InfluxDBException: {"error":"unable to parse 
    '[{
      "measurement":"sensor",
      "time":1559720142,
      "tags":{"test_tag":"test"},
      "fields":{
        "id":3,
        "date":1559718332366,
        "info":"info sensor3",
        "aleatory_number":141969819,
        "aleatory_number_square_root":11915.108
        }
    }]': missing tag value"}
  </code></pre>