Pt-online-schema-change --execute fails to connect after MySQL 8 upgrade, but --dry-run still works

MySQL & MariaDB
6

Hi,
I found around for this :

  • pt-online-schema-change is PERL script and you can edit it
  • see line 2340, after “my $tries = 2;”
  • something is wrong with $cxn_string - it include strange IP address. I don’t know where this is getting IP, because it is not nslookup of RDS URL (also not of RDS replica)
  • first I add “print “\nConnect string before : $cxn_string\n”;” after “my $tries = 2;” (line 2341)
  • after getting this value, I tool IP address and replace it with my primary RDS hostname
  • example : “$cxn_string =~ s/10.1.1.110/mkprod.REMOVEKEY.eu-central-1.rds.amazonaws.com/;”
    And then it is working. I have successful extended 2 RDS instances with primary+replica.