2947b099db
Add a multi-primary mode option that supports MySQL DB setups
that use circular replication with STATEMENT formatted binlogs.
The `modtoken` column is only used when multi-primary mode is
explicitly enabled in configuration. The column is used by write
queries to determine the "winning" version of keys, with the goal
of approximating "Last-Write-Wins" eventual consistency.
Writes with different timestamps can be handled by picking the
one with the highest timestamp as the "winner". Writes with the
same timestamp, from different primary DBs, can be handled by
picking the one from the primary DB with the highest server_id.
Writes with the same token timestamp from the same primary DB can
be handled by picking the last write to appear in the binlog.
The delete() operation uses tombstones in multi-primary mode,
since there must be a key version to actually compare with the
versions from other operations.
Also:
* Remove "LOCK IN SHARE MODE" that was made obsolete by the
CONN_TRX_AUTOCOMMIT flag. For the SQLite transaction case,
it is serializable anyway.
* Simplified handleWriteError() to match handleReadError()
and merged them into handleDBError().
Changes from
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| .. | ||
| APCUBagOStuffTest.php | ||
| BagOStuffTest.php | ||
| BagOStuffTestBase.php | ||
| MultiWriteBagOStuffTest.php | ||