large memory usage increment from about 300M to 10G since v2.1.9 (more than 10 times of v2.1.8)

[hsingli20]

Bug Report

Describe the bug Large memory usage increment from about 300M to 10G since v2.1.9 (more than 10 times of v2.1.8) The memory of container will keep increasing until close to 10G. Memory increases in a sawtooth pattern and then releases. Under the same traffic test and the same configurations for fluentbit, the version v2.1.9 seems introducing such new memory usage pattern, this will cause more memory usage reserved for fluentbit to avoid OOM kill issue.

To Reproduce

• Rubular link if applicable: 100%

• Steps to reproduce the problem:

  1. stress the logging traffic
  2. monitor the memory usage Expected behavior

Screenshots

Your Environment

• Version used: v2.1.9
• Configuration:

  
  [INPUT]
  name                tail
  tag                 event.kafka.ingress
  alias               kafka.ingress
  buffer_chunk_size   1m
  buffer_max_size     1m
  read_from_head      true
  refresh_interval    5
  rotate_wait         10
  skip_empty_lines    off
  skip_long_lines     true
  key                 message
  db                  /var/log/kafka.ingress.db
  db.sync             normal
  db.locking          true
  db.journal_mode     off
  db.compare_filename true
  path                /var/log/app/*
  exclude_path        /var/log/app/xxx.log,/var/log/app/ingress/*.gz,/var/log/app/ingress/*.tgz
  mem_buf_limit       20MB
  parser              json
  ignore_older        11m

* Environment name and version (e.g. Kubernetes? What version?): kubernetes
![MicrosoftTeams-image (1)](https://github.com/fluent/fluent-bit/assets/59753717/ae22f87a-4c9c-4d61-a797-29ea03cf05c5)

[edsiper]

please provide the full configuration including filters and outputs.