Pt-online schema change altering host IP; can't bypass replication checks

Polyglot Projects Percona Toolkit
1

Hello,

I’m trying to use pt-online-schema-change version 3.7.1 with MySQL 8.0.42 on AWS Aurora.

I’m having the same issue described here, where it’s changing my host string to an IP address I can’t access.

I’m tried seemingly every possible variation/combination of flags, but I can’t seem to bypass replication checks or stop it from running CHECK SLAVE STATUS; to pick up the write master host IP (which we can’t use). I can get it to work fine with --dry-run or if I resort to --force, but I’d prefer to keep the schema/data integrity checks intact.

Here are some of the flags I’ve tried, either alone or in combination with each other:

  • --recursion-method=none
  • --recursion-method=NONE
  • --recursion-method='dsn=D=percona,t=dsns' (pointing at empty table)
  • --recursion-method=hosts
  • --nocheck-replication-filters
  • --skip-check-replica-lag
  • --skip-check-slave-lag
  • --recurse=0

None of them seemed to make any difference in behavior with PTDEBUG=1, though they seemed to be getting parsed correctly. With --execute it just hangs until the connection eventually times out, though it can apparently do version checks and read variables just fine.

I would have created a ticket, but the exposed Jira portal is unresponsive to the point of being unusable.

2

Hi @Alex_Porter ,

Welcome to Percona community.

You’re right in disabling the replication check as it makes complete sense due to the way Aurora replicates.

The recursion method none should do the trick but I’d ask you to rerun the command with the options: --recursion-method=none --nocheck-replication-filters

Also, provide us with initial few lines atleast that shows the tool has identified the replicas and recusion-method flag is invalid along with full command.

Thanks,
K