Custom 'CHANGE MASTER TO' params

[shlomi-noach]

Is your feature request related to a problem? Please describe.
I wish to set up my replicas with specific parameters. e.g. MASTER_CONNECT_RETRY=1 (as opposed to the default 60) or MASTER_RETRY_COUNT=<somevalue>

The two specific replication params I mentioned are essential for quick(er) failure resolution.

Describe the solution you'd like
dbdeployer deploy to support --change-master-options [stringArray], similarly to --my-cnf-options. Example usage:

$ dbdeployer deploy replication 5.7.26 \
  --gtid \
  --my-cnf-options="slave_net_timeout=2" \
  --change-master-options="MASTER_CONNECT_RETRY=1" \
  --change-master-options="MASTER_RETRY_COUNT=10" \

Describe alternatives you've considered
the current alternative is to (post deploy) run stop slave; change master to... ; start slave on all replicas.

Thank you for your consideration.

[datacharmer]

Thanks for this feature request.
It can be added easily.
In the meantime, here's a workaround to achieve the goal with the current features:

0. (optional) dbdeployer defaults templates list replication
1. dbdeployer defaults templates show init_slaves_template > /tmp/init.tmpl
2. Edit the file /tmp/init.tmpl to include the options you'd like.
3. Run replication as

dbdeployer deploy replication 5.7.26 \
  --gtid \
  --my-cnf-options="slave_net_timeout=2" \
  --use-template=init_slave_template:/tmp/init.tmpl

The file initialize_slaves will be generated (and later run) with the changes you have added to the template. See Sandbox Customization for more info.

[shlomi-noach]

Thank you, I can confirm the workaround works, per openark/orchestrator-ci-env#17

[datacharmer]

Implemented in v1.49.0

[shlomi-noach]

Thank you for releasing v1.49.0! Just as addendum (possibly worth opening a new issue), dbdeployer deploy --help does not indicate the new --change-master-options flags, although I can confirm they work.

[datacharmer]

Thanks for confirming that the new flags works.

As for the help, the flag --change-master-options belongs to the sub-command deploy replication, not just deploy, as it is not applicable to single sandboxes. Similarly to the flag --prompt that applies to single deployments but not to replication.

[shlomi-noach]

Perfect, thank you!