Change in GET_LOCK call to make it MariaDB compatilble #5343
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Change in GET_LOCK call to make it MariaDB compatilble
pavel-usov
changed the title
physical/mysql/mysql.go
Outdated
| @@ -620,7 +620,7 @@ func (i *MySQLLock) becomeLeader() error { | |||
| func (i *MySQLLock) Lock() error { | |||
| defer metrics.MeasureSince([]string{"mysql", "get_lock"}, time.Now()) | |||
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| rows, err := i.in.Query("SELECT GET_LOCK(?, -1), IS_USED_LOCK(?)", i.key, i.key) | |||
| rows, err := i.in.Query("SELECT GET_LOCK(?, 4294967295), IS_USED_LOCK(?)", i.key, i.key) | |||
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How was this number chosen?
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This number is the decimal representation of maximal integer with 64bit length. In hexadecimal this number should be 0xffffffff
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Can we instead use math.MaxUint32 from the https://golang.org/pkg/math/ package and add a comment above that about -1 not being compatible with different MySQL flavours?
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@michaeljs1990 Yes, we can use this constant. I tested this, committed changes and comments.
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Same problem faced. Can you help with steps on how to apply this fix on a running mysql deployment?
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You shouldn't need to make any changes to mysql for this fix. What is the issue you are running into?
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@michaeljs1990 could you take a look at this? |
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Thanks for the improvement to make this work on MariaDB! I admit the -1 is a rather undocumented get lock feature but it seemed common enough in other software I had worked with I didn't think it would cause issues. |
Change in GET_LOCK call to make it MariaDB compatilble. This should resolve Issue 5266
The fix creates a lock with a timeout of 136 years which is failry enough to be considered as "unlimited"