Add --test-on-replica-manual-replication-control flag #174
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This will wait indefinitely for the replication status to change. This allows us to run test schema changes in RDS without needing custom RDS commands in gh-ost.
| } | ||
| migrationContext.TestOnReplica = true | ||
| migrationContext.ManualReplicationControl = true | ||
| } |
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@shlomi-noach , in my opinion the code reads more complicated to me when there are two flags that have the same core functionality, with this one slight variation.
I think the semantics would be more clear if we still used the --test-on-replica flag and had a separate flag that just customized this one aspect of its behavior. So if one wants to have manual replication control, one would use the args:
--test-on-replica --manual-replication-control
Without the extra flag, --test-on-replica would behave as it always has.
What do you think?
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That was my original intention. The flag is good to be named --test-on-replica-skip-stop-replica or whatever, but it would be an addon to --test-on-replica. Not only are the flags not mutually exclusive, the --test-on-replica-skip-stop-replica is only applicable when --test-on-replica exists.
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Ah, I understand now. My apologies for the confusion. I'll update the logic.
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See comments inline |
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I've updated the flag and behavior we discussed. It is now an add-on flag to |
| if !migrationContext.TestOnReplica { | ||
| log.Fatalf("--test-on-replica-skip-replica-stop requires --test-on-replica to be enabled") | ||
| } | ||
| log.Warning("--test-on-replica-skip-replica-stop enabled. We will not stop replication before cut-over. Ensure you have a plugin that does this.") |
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I've made mention of plugins (prematurely) in the warning because I don't think this feature will really work without them.
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Not at all. I'll take a look first thing tomorrow. |
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Actually, that was simple, just did it now. :) |
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@pbitty this is what it would look like once #190 is merged: https://github.com/github/gh-ost/pull/190/files#diff-e2990679ccfa83d6fc15414958333bcbR523 |
This will wait indefinitely for the replication status to change.
This allows us to run test schema changes in RDS without needing
custom RDS commands in gh-ost.
Closes #162