do not sync persistent store when get a fake position #397
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@siddontang PTAL |
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PTAL @GregoryIan |
canal/sync.go
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| @@ -65,6 +65,10 @@ func (c *Canal) runSyncBinlog() error { | |||
| // TODO: If we meet any DDL query, we must save too. | |||
| switch e := ev.Event.(type) { | |||
| case *replication.RotateEvent: | |||
| // if event pos equal to local pos.maybe be fake rotate event,do nothing. | |||
| if string(e.NextLogName) == pos.Name && uint32(e.Position) == pos.Pos { | |||
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in MySQL, a fake rotate event is an event with timestamp equals to 0 (see https://github.com/mysql/mysql-server/blob/8cc757da3d87bf4a1f07dcfb2d3c96fed3806870/sql/rpl_binlog_sender.cc#L899), and also with log pos equals to 0 in the implementation (see https://github.com/mysql/mysql-server/blob/8cc757da3d87bf4a1f07dcfb2d3c96fed3806870/sql/rpl_binlog_sender.cc#L906).
I don't know whether some corner cases exist if checking by string(e.NextLogName) == pos.Name && uint32(e.Position) == pos.Pos.
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Friendly ping @lintanghui
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in MySQL, a fake rotate event is an event with timestamp equals to 0 (see https://github.com/mysql/mysql-server/blob/8cc757da3d87bf4a1f07dcfb2d3c96fed3806870/sql/rpl_binlog_sender.cc#L899), and also with log pos equals to 0 in the implementation (see https://github.com/mysql/mysql-server/blob/8cc757da3d87bf4a1f07dcfb2d3c96fed3806870/sql/rpl_binlog_sender.cc#L906).
I don't know whether some corner cases exist if checking by
string(e.NextLogName) == pos.Name && uint32(e.Position) == pos.Pos.
yes, timestamp 0 and pos 0 is set in event header, but in event body, pos and file name is also be set, https://github.com/mysql/mysql-server/blob/8cc757da3d87bf4a1f07dcfb2d3c96fed3806870/sql/rpl_binlog_sender.cc#L909 . in sync.go we just get event body and compare it. we can also do such below
ev.Header.Pos==0 {continue }
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@lintanghui I know, in this special case string(e.NextLogName) == pos.Name && uint32(e.Position) == pos.Pos is right, but I don't know whether some corner cases exist.
BTW, will you update it to ev.Header.Pos==0 {continue }?
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fine, it seem better to compare header pos.
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PTAL @GregoryIan . it's that ok to be merge? |
fixed #396