Logstash conditional statement not working

[Shabu]

I want to use a conditional statement in my logstash config, so that syslogs are sent to "syslogindex" and other logs are sent to "testindex". I have tried multiple things, but It just does not work. This is my config:

The Logstash log then always shows something like "_index => Testindex, Reason: Could not index event to elasticsearch. Object mapping for [host] tried to parse field [host] as object, but found a concrete value". This tells me that the condition is not working and the logs are sent to the wrong index, which is not configured to take syslogs

How can I make the condition work?

[Wolfram_Haussig]

Hi,

I am not aware that Logstash automatically adds the input name as tag, you could try adding the tag manually:

input {
  syslog {
    port => 514
    tags => ["syslog"]
  }
}

Best regards
Wolfram

[Shabu]

Adding the tag makes the logs go to the correct index now, but I still receive the mapping error. I tried creating a new, simple mapping. But here I receive the error "mapper [message] cannot be changed from type [match_only_text] to [text]". This is my mapping:

{
  "properties": {
    "@timestamp": {
      "type": "date"
    },
    "host": {
      "type": "keyword"
    },
    "facility": {
      "type": "keyword"
    },
    "severity": {
      "type": "keyword"
    },
    "message": {
      "type": "text"
    },
    "switch": {
      "type": "keyword"
    },
    "port": {
      "type": "keyword"
    },
    "vlan": {
      "type": "keyword"
    } 
  }
}

[Wolfram_Haussig]

You cannot change the mapping of a field when this field already exists. Normally, when using Index Lifecycle Management, you would update the mapping in the index template and then rollover the write alias. This creates a new index with the new mapping.
If you do not use Lifecycle Management, you would need to create a new index manually and point Logstash to it.

[Shabu]

I tried changing the mapping again and just removed the fields that would result in a type change error. This way, the fields that were already working were left unchanged and the new ones were added. Thank you for your time