Behavior of a deleted pipeline

Hello,

I had to delete and reinstall Filebeat because of some things I did wrong. In the old configuration I had, it gave me some available fields which are also in the new old, even if the pipeline doesn't exist (like host.hostname).

Alongside, when I PUT /_ingest/pipeline/filebeat-7.5.2-system-syslog-pipeline, the old pipeline, it doesn't give me anything even if it worked perfectly on the old one.

Do you know why and how to resolve it ? Thanks a lot.

Here is the pipeline I talk about and it was unchanged :

PUT /_ingest/pipeline/filebeat-7.5.2-system-syslog-pipeline
{
  "description": "Pipeline for parsing Syslog messages.",
  "processors": [
    {
      "grok": {
        "pattern_definitions": {
          "GREEDYMULTILINE": "(.|)*"
        },
        "ignore_missing": true,
        "field": "message",
        "patterns": [
          "%{SYSLOGTIMESTAMP:system.syslog.timestamp} %{SYSLOGHOST:host.hostname} %{DATA:process.name}(?:\\[%{POSINT:process.pid:long}\\])?: %{GREEDYMULTILINE:system.syslog.message}",
          "%{TIMESTAMP_ISO8601:system.syslog.timestamp} %{SYSLOGHOST:host.hostname} %{DATA:process.name}(?:\\[%{POSINT:process.pid:long}\\])?: %{GREEDYMULTILINE:system.syslog.message}",
           "%{SYSLOGTIMESTAMP:system.syslog.timestamp} %{GREEDYMULTILINE:system.syslog.message}"
        ]
      }
    },
    {
      "rename": {
        "field": "system.syslog.message",
        "target_field": "message",
        "ignore_missing": true
      }
    },
    {
      "date": {
        "formats": [
          "MMM  d HH:mm:ss",
          "MMM dd HH:mm:ss",
          "MMM d HH:mm:ss",
          "ISO8601"
        ],
        "on_failure": [
          {
            "append": {
              "field": "error.message",
              "value": "{{ _ingest.on_failure_message }}"
            }
          }
        ],
        "if": "ctx.event.timezone == null",
        "field": "system.syslog.timestamp",
        "target_field": "@timestamp"
      }
    },
    {
      "date": {
        "if": "ctx.event.timezone != null",
        "field": "system.syslog.timestamp",
        "target_field": "@timestamp",
        "formats": [
          "MMM  d HH:mm:ss",
          "MMM dd HH:mm:ss",
          "MMM d HH:mm:ss",
          "ISO8601"
        ],
        "timezone": "{{ event.timezone }}",
        "on_failure": [
          {
            "append": {
              "field": "error.message",
              "value": "{{ _ingest.on_failure_message }}"
            }
          }
        ]
      }
    },
    {
      "remove": {
        "field": "system.syslog.timestamp"
      }
    }
  ],
  "on_failure": [
    {
      "set": {
        "field": "error.message",
        "value": "{{ _ingest.on_failure_message }}"
      }
    }
  ]
}

I finally fix it.

Actually, I update FIlebeat but it was still looking at the 7.5 version instead of the 7.6. A directory for the 7.6 version was created, but not on the /etc/filebeat/ so I had to move the files to take over the old one.