ES Modify note

• helm pull elastic/elasticsearch --version 7.17.3 --untar

  • untar means unzip files

• helm fetch elastic/elasticsearch --version --untar --untardir

• tgz zxvf

• unzip to the folder and compare

Upgrade note:

• need to wait until cluster ready.
  • re-index process.
• can validate by 2 process
  • check by dev tool
  • readiness:
    • will check flag green, then it's ready.
• Q: is it possible to have less than 2 nodes?
• A: 2 node might have brain-split issue. suggest using 3 node cluster would be safer.